Common use of INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE Clause in Contracts

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectus. The information incorporated by reference is considered to be part of this prospectus, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of charge, a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “"incorporate by reference” " into this prospectus supplement and the accompanying base prospectus certain information we file with it which it. This means that we can disclose important information to you in this prospectus supplement by referring you to those documents. These incorporated documents instead of having to repeat contain important business and financial information about us that is not included in or delivered with this prospectus supplement or the information in this accompanying base prospectus. The information incorporated by reference is considered to be part of this prospectus supplement and the accompanying base prospectus, and later information that we file filed with the SEC will automatically update and supersede the information contained in this informationprospectus supplement and the accompanying base prospectus. We incorporate by reference the documents listed below and as well as any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statementAct, and (ii) from the date of this prospectus and before supplement to the completion of the all offerings of the particular securities included offered by this prospectus supplement, except that we do not incorporate any document or portion of a document that is "furnished" to the SEC, but not deemed "filed." The following documents filed with the SEC are incorporated by reference in this prospectus. · Our annual report : • our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2016, filed with the SEC on February 22March 31, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with 2017, including the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our information specifically incorporated by reference into such Annual Report from our definitive proxy statement on Schedule 14A for our Annual Meeting of Stockholders held on May 31, 2017 and filed with the SEC on July 18May 1, 2017 (File No. 001-12584)2017; and · The description of • our common stock set forth in our registration statement Quarterly Reports on Form 810-A12BQ for the fiscal quarter ended April 1, 2017, filed with the SEC on May 16, 2017, the fiscal quarter ended July 1, 2017, filed with the SEC on August 15, 2017, and the fiscal quarter ended September 30, 2017, filed with the SEC on November 14, 2017; • our Current Reports on Form 8-K filed on March 29, 2017, April 14, 2017, April 17, 2017, May 5, 2017, May 9, 2017, June 201, 2007 (File No2017, August 17, 2017 and September 29, 2017; and • the description of our common stock contained in our Registration Statement on Form 8-A filed with the SEC on November 27, 2006, including any amendments or reports filed for the purpose of updating such description. 000-12584). You may obtainWe will provide without charge to each person, free including any beneficial owner, to whom a prospectus is delivered, on written or oral request of chargethat person, a copy of any or all of these the documents (we are incorporating by reference into this prospectus supplement or the accompanying base prospectus, other than exhibits to these those documents unless the such exhibits are specifically incorporated by reference into these documents or referred those documents. Such written requests should be addressed to: You may direct telephone requests to in this prospectus) by writing or calling us our Investor Relations Department at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000. We may offer and sell from time to time the above securities in one or more classes, in one or more transactions, separately or together in any combination and as separate series, and in amounts, at prices and on terms that we will determine at the times of the offerings. We may also offer any of these securities that may be issuable upon the conversion, exercise or exchange of preferred stock or warrants. The aggregate initial offering price of the securities that we may offer through this prospectus will be up to $40,000,000. We will provide specific terms of any offering in supplements to this prospectus, which we will deliver together with the prospectus at the time of sale. The supplements may add, update or change information contained in this prospectus. You should read this prospectus and any prospectus supplement carefully before you invest. This prospectus may not be used to offer and sell securities unless accompanied by a prospectus supplement. We may offer the securities independently or together in any combination for sale directly to purchasers, through one or more underwriters, dealers or agents, or through underwriting syndicates managed or co-managed by one or more underwriters, to be designated at a future date, on a continuous or delayed basis. Our common stock is listed on the NASDAQ Capital Market under the symbol "NLST." On August 17, 2016, the last reported sale price of our common stock was $1.60 per share. This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, or SEC, using a "shelf" registration process. Under this shelf registration process, we may, from time to time, sell the securities or combinations of the securities described in this prospectus in one or more offerings in amounts that we will determine from time to time. For further information about our business and the securities, you should refer to the registration statement containing this prospectus and its exhibits. The exhibits to our registration statement contain the full text of certain contracts and other important documents we have summarized in this prospectus. Since these summaries may not contain all the information that you may find important in deciding whether to purchase the securities we offer, you should review the full text of these documents. We have filed and plan to continue to file other documents with the SEC that contain information about us and our business. Also, we will file legal documents that control the terms of the securities offered by this prospectus as exhibits to the reports we file by the SEC. The registration statement and other reports can be obtained from the SEC as indicated under the heading "Where You Can Find More Information." This prospectus provides you with a general description of the securities that we may offer. Each time we offer securities pursuant to this prospectus, we will provide a prospectus supplement and/or other offering material that will contain specific information about the terms of that offering. When we refer to a "prospectus supplement," we are also referring to any free writing prospectus or other offering material authorized by us. The prospectus supplement may also add, update or change information contained in this prospectus. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement, you should rely on the information in the prospectus supplement or incorporated information having a later date. You should read this prospectus and any prospectus supplement together with additional information described under the headings "Incorporation of Certain Documents by Reference" and "Where You Can Find More Information." You should rely only on the information provided in this prospectus, in any prospectus supplement, or any other offering material that we authorize, including the information incorporated by reference. We have not authorized anyone to provide you with different information. You should not assume that the information in this prospectus, any supplement to this prospectus, or any other offering material that we authorize, is accurate at any date other than the date indicated on the cover page of these documents or the date of the statement contained in any incorporated documents, respectively. This prospectus is not an offer to sell or a solicitation of an offer to buy any securities other than the securities referred to in the prospectus supplement. This prospectus is not an offer to sell or a solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should not interpret the delivery of this prospectus, or any sale of securities, as an indication that there has been no change in our affairs since the date of this prospectus. You should also be aware that information in this prospectus may change after this date. The information contained in this prospectus or a prospectus supplement or amendment, or incorporated herein or therein by reference, is accurate only as of the date of this prospectus or prospectus supplement or amendment, as applicable, regardless of the time of delivery of this prospectus or prospectus supplement or amendment, as applicable, or of any sale of the shares. Unless the context otherwise requires, in this prospectus "Netlist," "we," "us," and "our" refer to Netlist, Inc. and its consolidated subsidiaries.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC Commission allows us the Company to “incorporate by reference” the information we file it files with it the Commission, which means that we the Company can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information incorporated by reference is considered to be an important part of this prospectus, and later information that we file the Company files later with the SEC Commission will automatically update and supersede this information. We incorporate The following documents previously filed by the Company with the Commission are incorporated by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · Our annual report : • Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2010, filed with March 11, 2011, including portions of the SEC Company’s Proxy Statement for the 2011 Annual Meeting of Shareholders to the extent specifically incorporated by reference therein; • Quarterly Reports on February 22Form 10-Q for the fiscal quarter ended March 31, 2018 (File No. 001-12584)2011, filed May 9, 2011, and the fiscal quarter ended June 30, 2011, filed August 9, 2011; · Our current reports • Current Reports on Form 8-K filed February 1, 2011, February 10, 2011, April 28, 2011 (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC as amended on July 1828, 2017 (File No. 001-125842011), June 30, 2011, and July 6, 2011; and · • The description of our the Company’s common stock set forth contained in our registration statement the Registration Statement on Form 8-A12BB filed July 1, 1993. All reports and other documents subsequently filed with by the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of charge, a copy of any of these documents Company (other than exhibits any portion of such filings that are furnished under applicable rules of the Commission rather than filed) pursuant to these documents unless Sections 13(a) and 15(d) of the exhibits are specifically Exchange Act, prior to the termination of the offering pursuant to this prospectus, shall be deemed to be incorporated by reference into these documents this prospectus and to be part hereof from the date of filing of such reports and documents. Any statement contained in a document incorporated or referred deemed to be incorporated by reference into this prospectus shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained herein or in any other subsequently filed document which is also or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information that is incorporated by reference is considered to be part of this prospectus, and later the information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus the documents listed below following documents: · our Annual Report on Form 10-K for the year ended December 31, 2018, filed on March 13, 2019; · our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2019, filed on May 8, 2019, and for the quarter ended June 30, 2019, filed on August 8, 2019; (as amended on June 12, 2019), June 6, 2019, July 8, 2019, August 22, 2019, August 23, 2019, September 5, 2019, September 23, 2019, and October 3, 2019 (provided that any future filings made portions of such reports that are deemed furnished and not filed pursuant to instructions to Form 8-K shall not be incorporated by reference into this prospectus); and · the description of common stock set forth in or Registration Statement on Form 8-A12B filed with the SEC (other than any portions on November 5, 2014 pursuant to Section 12(b) of any such documents that are not deemed “filed” under the Exchange Act in accordance Act, including any amendment or report filed for the purpose of updating such description. All documents subsequently filed with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date termination of this prospectus and before the completion of the offerings of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of charge, a copy of any of these documents (other than exhibits offering shall be deemed to these documents unless the exhibits are specifically be incorporated by reference into these documents the prospectus. Any statement contained in any document incorporated by reference herein will be deemed to be modified or referred superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or any additional prospectus supplements modifies or supersedes such statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” into this prospectus the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information incorporated by reference is considered to be part of this prospectus, and later information in documents that we file later with the SEC will automatically update and supersede information in this informationprospectus. We incorporate by reference into this prospectus the documents listed below and any future filings, including all filings made after the date of the filing of the registration statement of which this prospectus is a part and prior to the effectiveness of such registration statement, made by us with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior Act, except for information “furnished” under Items 2.02, 7.01 or 9.01 on Form 8-K or other information “furnished” to the effectiveness of the registration statementSEC, which is not deemed filed and (ii) the date of this prospectus and before the completion of the offerings of the securities included not incorporated in this prospectus, until the termination of the offering of securities described in the applicable prospectus supplement. · Our annual report We hereby incorporate by reference the following documents: • our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2020, as filed with the SEC on February 2226, 2018 (File No. 0012021; • the information specifically incorporated by reference into our Annual Report on Form 10-12584)K for the year ended December 31, 2020 from our definitive proxy statement on Schedule 14A, as filed with the SEC on April 27, 2021; · Our current reports • our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2021, June 30, 2021 and September 30, 2021, as filed with the SEC on May 10, 2021, August 6, 2021 and November 9, 2021, respectively; • our Current Reports on Form 8-K (File No. 001-12584) filed with the SEC on January 85, 20182021, March 711, 2018; 2021, April 239, 2018 2021, June 17, 2021, August 16, 2021, September 10, 2021 and May 7October 29, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584)2021; and · The • the description of our common stock set forth contained in our registration statement Registration Statement on Form 8-A12BA, as filed with the SEC on June 2023, 2007 (File No2017, including any amendment or report filed for the purpose of updating such description. 000-12584)Any statement contained in a document incorporated or deemed to be incorporated by reference in this prospectus will be deemed modified, superseded or replaced for purposes of this prospectus to the extent that a statement contained in this prospectus modifies, supersedes or replaces such statement. You may obtain, free of charge, request a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) filings, at no cost, by writing or calling telephoning us at the following address address: Copies of these filings are also available, without charge, on the SEC’s website at xxx.xxx.xxx and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxxon our website at xxx.xxxxxxx.xxx as soon as reasonably practicable after they are filed electronically with the SEC. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number The information contained on our website is (000) 000-0000not a part of this prospectus.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it into this prospectus, which means that we can disclose important information to you by referring you to those documents instead of having to repeat another document filed separately with the information in this prospectusSEC. The information SEC file number for the documents incorporated by reference in this prospectus is considered to be part of 001-35994. The documents incorporated by reference into this prospectus, and later prospectus contain important information that we file you should read about us. The following documents are incorporated by reference into this document: · Our Annual Report on Form 10-K for the year ended December 31, 2019 (Commission File No. 001-35994) filed with the SEC will automatically update on March 30, 2020; · Our Current Reports on Form 8-K (Commission File No. 001-35994) filed with the SEC onJanuary 3, 2020, January 21, 2020, February 5, 2020, February 21, 2020, February 27, 2020, March 2, 2020, March 3, 2020, March 5, 2020, March 11, 2020, March 13, 2020, March 17, 2020, March 23, 2020, March 23, 2020, and supersede this informationApril 10, 2020; · Our Definitive Proxy Statement on Schedule 14A filed with the SEC on January 24, 2020; · The description of our common stock set forth in our registration statement onForm 8-A filed with the SEC on July 8, 2013 (Commission File No. 001-35994); and · The description of our common stock purchase rights set forth in our registration statement on Form 8-A filed with the SEC onMarch 12, 2018, Form 8-A/A (Amendment No. 1) filed on March 13, 2019, Form 8-A/A (Amendment No. 2) filed with the SEC onMarch 13, 2020 (Commission File No. 001-35994). We also incorporate by reference the into this prospectus all documents listed below (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and any future filings made exhibits filed on such form that are related to such items) that are filed by us with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) after the date of the initial filing of the registration statement of which this prospectus forms a part and prior to the effectiveness of the registration statement, and or (ii) after the date of this prospectus and before but prior to the completion termination of the offerings of the securities included in this prospectusoffering. · Our annual report These documents include periodic reports, such as Annual Reports on Form 10-K for the fiscal year ended December 31K, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports Quarterly Reports on Form 810-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 Q and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement Current Reports on Form 8-A12B8- K, filed with the SEC on June 20, 2007 (File No. 000-12584)as well as proxy statements. You may obtain, free of charge, a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic BiologicsAny statement contained in this registration statement or in a document incorporated or deemed to be incorporated by reference in this registration statement shall be deemed to be modified or superseded for purposes of this registration statement to the extent that a statement contained in this registration statement or in any other subsequently filed document which also is or is deemed to be incorporated by reference in this registration statement modifies or supersedes that statement. Any statement so modified or superseded shall not be deemed, Inc.except as so modified or superseded, 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000to constitute a part of this registration statement.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the reference information we file with it which into this document. This means that we can disclose important information to you by referring you to those documents instead of having to repeat another document filed separately with the information in this prospectusSEC. The information incorporated by reference is considered to be an important part of this prospectusprospectus supplement, and later information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections Section 13(a), 13(c), 14 14, or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior made subsequent to the effectiveness of the registration statement, and (ii) the date of this prospectus and before supplement until the completion termination of the offerings offering of the securities included described in this prospectusprospectus supplement (other than information in such filings that was “furnished,” under applicable SEC rules, rather than “filed”). · Our annual report We incorporate by reference the following documents or information that we have filed with the SEC: • our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2019 filed with the SEC on March 12, 2020; • our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2020 filed with the SEC on June 1, 2020, as amended on June 1, 2020, and for the quarter ended June 30, 2020 filed with the SEC on August 10, 2020; • our definitive Proxy Statement for our Annual Meeting of Stockholders held on June 7, 2020 filed with the SEC on April 15, 2020; • our Current Reports on Form 8-K filed with the SEC on February 226, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 2020, March 12, 2020, March 18, 2020, May 11, 2020, May 11, 2020, May 28, 2020, June 8, 20182020, March 7August 11, 2018; April 232020 and September 8, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584)2020; and · The • the description of our common stock set forth included in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 A12B (File No. 000001-12584)33357) filed with the Commission on March 9, 2007, including any amendment or reports filed for the purpose of updating such description. You Copies of these filings are available at no cost on our website, xxx.xxxxxxxx.xxx. In addition, you may obtain, free of charge, request a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) filings at no cost by writing or calling telephoning us at the following address address: You should rely only on the information incorporated by reference or provided in this prospectus supplement or the accompanying base prospectus. We have not authorized anyone else to provide you with different or additional information. An offer of these securities is not being made in any jurisdiction where the offer or sale is not permitted. You should not assume that the information in this prospectus supplement or the accompanying base prospectus is accurate as of any date other than the date on the front of those documents. We may from time to time offer, in one or more series, separately or together, the following: • our common stock; • our preferred stock in one or more series; • debt securities in one or more series; and telephone number• warrants to purchase our common stock. The aggregate public offering price of the securities that we may offer through this prospectus will be up to $100,000,000. We will provide the specific terms of the securities offered by us in supplements to this prospectus, which we will deliver together with the prospectus at the time of sale. This prospectus may not be used to sell securities unless accompanied by a prospectus supplement. Please read this prospectus and the applicable prospectus supplement carefully before you invest in any of our securities. We may, from time to time, offer and sell these securities directly or through one or more underwriters, agents or dealers, through underwriting syndicates managed or co-managed by one or more underwriters, or directly to purchasers, on or off the NYSE American at prevailing market prices or at privately negotiated prices, on a continuous or delayed basis. Our common stock is listed on the NYSE American under the symbol “PLX” and on the Tel Aviv Stock Exchange under the symbol “PLX.” On March 28, 2019, the last reported sale price of our common stock was $0.43 per share on the NYSE American and NIS 1.58 per share on the Tel Aviv Stock Exchange. ABOUT THIS PROSPECTUS 1 OUR BUSINESS 2 RISK FACTORS 4 USE OF PROCEEDS 4 DILUTION 4 SECURITIES WE MAY OFFER 5 DESCRIPTION OF EQUITY SECURITIES 6 DESCRIPTION OF DEBT SECURITIES 10 PLAN OF DISTRIBUTION 15 WHERE YOU CAN FIND MORE INFORMATION 17 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE 18 LEGAL MATTERS 19 EXPERTS 19 The statements set forth and incorporated by reference in this prospectus, which are not historical, constitute “forward- looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, including statements regarding the expectations, beliefs, intentions or strategies for the future. When used in this prospectus, or in any document incorporated by reference in this prospectus, the terms “anticipate,” “believe,” “estimate,” “expect,” “can,” “continue,” “could,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” and words or phrases of similar import, as they relate to our company or our subsidiaries or our management, are intended to identify forward-looking statements. These forward-looking statements are only predictions and reflect our views as of the date they are made with respect to future events and financial performance, and we undertake no obligation to update or revise, nor do we have a policy of updating or revising, any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events, except as may be required under applicable law. We intend that all forward-looking statements be subject to the safe- harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are subject to many risks and uncertainties that could cause our actual results to differ materially from any future results expressed or implied by the forward-looking statements. Examples of the risks and uncertainties include, but are not limited to, the following: Synthetic Biologics• failure or delay in the commencement or completion of our preclinical studies and clinical trials, which may be caused by several factors, including: slower than expected rates of patient recruitment; unforeseen safety issues; determination of dosing issues; lack of effectiveness during clinical trials; inability or unwillingness of medical investigators and institutional review boards to follow our clinical protocols; inability to monitor patients adequately during or after treatment; and or lack of sufficient funding to finance our clinical trials; • the risk that the results of our clinical trials will not support the applicable claims of superiority, safety or efficacy and that our product candidates will not have the desired effects or will have undesirable side effects or other unexpected characteristics; • the risk that the U.S. Food and Drug Administration, or the FDA, or foreign regulatory authorities may not accept or approve a marketing application we file for any of our product candidates; • our ability to remediate the material weakness in internal control over financial reporting and to maintain effective internal control over financial reporting; • risks relating to our ability to manage our relationship with Chiesi Farmaceutici S.p.A., or Xxxxxx, and any other collaborator, distributor or partner; • risks relating to our ability to make scheduled payments of the principal of, to pay interest on or to refinance or satisfy conversions of our outstanding convertible notes or any other indebtedness; • risks relating to the compliance by Fundação Xxxxxxx Xxxx, or Fiocruz, an arm of the Brazilian Ministry of Health, or the Brazilian MoH, with its purchase obligations under our supply and technology transfer agreement, which may have a material adverse effect on us and may also result in the termination of such agreement; • risks related to our ability to maintain compliance with the continued listing standards of the NYSE American; • our dependence on performance by third-party providers of services and supplies, including without limitation, clinical trial services; • risks relating to our ability to finance our activities and research programs; • delays in preparing and filing applications for regulatory approval of our product candidates in the United States, the European Union and elsewhere; • the impact of development of competing therapies and/or technologies by other companies; • the risk that products that are competitive to our product candidates may be granted orphan drug status in certain territories and, therefore, one or more of our product candidates may become be subject to potential marketing and commercialization restrictions; • risks related to our supply of drug product to Pfizer Inc., 0000 Xxxxxxx Xxxxxx Xxxxxor Pfizer, Xxxpursuant to our amended and restated exclusive license and supply agreement with Pfizer, or the Amended Pfizer Agreement; • risks related to the commercialization efforts for taliglucerase alfa in Brazil; • risks related to our expectations with respect to the potential commercial value of our product and product candidates; • the inherent risks and uncertainties in developing the types of drug platforms and products we are developing; • potential product liability risks, and risks of securing adequate levels of product liability and clinical trial insurance coverage; • the possibility of infringing a third-party’s patents or other intellectual property rights; • the uncertainty of obtaining patents covering our products and processes and in successfully enforcing our intellectual property rights against third- parties; • risks relating to changes in healthcare laws, rules and regulations in the United States, the European Union or elsewhere; and • the possible disruption of our operations due to terrorist activities and armed conflict, including as a result of the disruption of the operations of regulatory authorities, our subsidiaries, our manufacturing facilities and our customers, suppliers, distributors, collaborative partners, licensees and clinical trial sites. 000Companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in advanced or late-stage clinical trials, Xxxxxxxxxeven after obtaining promising earlier trial results or preliminary findings for such clinical trials. Even if favorable testing data is generated from clinical trials of a drug product, Xxxxxxxx 00000the FDA or foreign regulatory authorities may not accept or approve a marketing application filed by a pharmaceutical or biotechnology company for the drug product. Our telephone number is (000) 000These forward-0000looking statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. These and other risks and uncertainties are detailed under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2018, and are described from time to time in the reports we file with the U.S. Securities and Exchange Commission, or the Commission.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information that is incorporated by reference is considered to be part of this prospectus, and later the information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus the documents listed below and any future filings made following documents: ● our Annual Report on Form 10-K for the year ended December 31, 2020, filed with the SEC onMarch 25, 2021; ● our definitive Proxy Statement on Schedule 14A for the 2021 Annual Meeting of Stockholders, filed April 7, 2021 (other than solely to the extent incorporated by reference into Part III of our Annual Report on Form 10-K for the fiscal year ended December 31, 2020); ● our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021 and June 30, 2021, filed with the SEC onMay 12, 2021 and August 11, 2021; ● our Current Reports on Form 8-K filed with the SEC onJanuary 4, 2021, January 19, 2021, January 26, 2021, February 1, 2021, February 3, 2021, March 2, 2021, March 25, 2021, April 28, 2021, May 12, 2021, May 28, 2021, May 28, 2021, June 14, 2021, July 20, 2021, July 27, 2021, August 12, 2021, August 12, 2021, August 16, 2021 and August 17, 2021 (provided that any portions of any such documents reports that are deemed furnished and not deemed “filed” under filed pursuant to instructions to Form 8-K shall not be incorporated by reference into this prospectus); and ● the Exchange Act description of common stock set forth in accordance Exhibit 4.11 to our Annual Report on Form 10-K for the year ended December 31, 2020, filed with the Exchange Act and applicable SEC rules) on March 25, 2021, including any amendment or report filed for the purpose of updating such description. All documents subsequently filed with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after prior to the termination of this offering shall be deemed to be incorporated by reference into this prospectus supplement. Any statement contained in any document incorporated by reference herein will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any additional prospectus supplement modifies or supersedes such statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement. We may offer from time to time in one or more offerings up to an aggregate of $250,000,000 of the common stock, preferred stock, debt securities, warrants or units described in this prospectus, separately or together in one or more combinations. The preferred stock, debt securities, and warrants may be convertible into or exercisable or exchangeable for common stock or preferred stock or other securities, as identified in the applicable prospectus supplement. This prospectus provides a general description of the securities we may offer. This prospectus will allow us to offer for sale securities over time. Each time we sell securities, we will provide specific terms of the securities offered in the applicable prospectus supplement. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference herein and therein, before you invest in any of our securities. This prospectus may not be used to sell the securities unless accompanied by a prospectus supplement. We may offer and sell the securities through underwriters, dealers or agents, or directly to purchasers, or through a combination of these methods. See “Plan of Distribution” beginning on page 16 of this prospectus. Our common stock is listed on the Nasdaq Global Market under the symbol “ADMA.” On May 26, 2021, the last reported sale price of our common stock was $1.72 per share. The date of this prospectus is May 28, 2021 TABLE OF CONTENTS Page Special Note Regarding Forward-Looking Statements 6 Description of the Securities We May Offer 9 This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission (ithe “SEC” or the “Commission”) using a “shelf” registration process under the Securities Act of 1933, as amended (the “Securities Act”). Under this shelf registration process, we may offer and sell, from time to time, any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $250,000,000. This prospectus provides a general description of the securities we may offer. Each time we sell the securities, we will, to the extent required by law, provide a prospectus supplement that will contain specific information about the terms of the offering. We may also authorize one or more free writing prospectuses to be provided to you in connection with the offering. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. You should carefully read this prospectus, the applicable prospectus supplement, and any applicable free writing prospectus, as well as the information and documents incorporated herein and therein by reference and the additional information under the heading “Where You Can Find More Information,” before making an investment decision. We have not authorized any dealer, salesman or other person to give any information or to make any representation other than those contained in, or incorporated by reference into, this prospectus and the applicable prospectus supplement, and any free writing prospectus we have authorized for use in connection with a specific offering. This prospectus and any accompanying prospectus supplement to this prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor do this prospectus or any accompanying prospectus supplement to this prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus, any accompanying prospectus supplement and any applicable free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the initial registration statement and prior document incorporated by reference, even though this prospectus, any accompanying prospectus supplement or any applicable free writing prospectus is delivered, or securities sold, on a later date. This prospectus may not be used by us to consummate sales of our securities unless it is accompanied by a prospectus supplement. To the effectiveness of the registration statementextent there are inconsistencies between any prospectus supplement, and (ii) the date of this prospectus and before any documents incorporated by reference, the completion of the offerings of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed document with the SEC on February 22most recent date will control. This prospectus supplement includes our trademarks, 2018 (File Notrade names and service marks, such as “BIVIGAM®,” “ASCENIV™” and “Nabi-HB®,” which are protected under applicable intellectual property laws and are the property of ADMA Biologics, Inc., or its subsidiaries. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8Solely for convenience, 2018trademarks, March 7, 2018; April 23, 2018 trade names and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of charge, a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or service marks referred to in this prospectus) by writing prospectus supplement may appear without the ®, TM or calling SM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the right of the applicable licensor to these trademarks, trade names and service marks. We do not intend our use or display of other parties’ trademarks, trade names or service marks to imply, and such use or display should not be construed to imply, a relationship with, or endorsement or sponsorship of us at by, these other parties. Unless the following address context otherwise requires, references in this prospectus to “we,” “us,” “our,” the “Company,” “ADMA Biologics” and telephone number: Synthetic “ADMA” refer to ADMA Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxxa Delaware corporation, Xxx. 000and its subsidiaries: ADMA BioCenters Georgia Inc., Xxxxxxxxxa Delaware corporation (“ADMA BioCenters”), Xxxxxxxx 00000. Our telephone number is ADMA BioManufacturing, LLC, a Delaware limited liability company (000) 000-0000“ADMA BioManufacturing”), and ADMA Plasma Biologics, Inc., a Delaware corporation (“ADMA Plasma”).

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “"incorporate by reference” " the information we file with it which them. This means that we can disclose important information to you in this prospectus by referring you to those documents. These incorporated documents instead of having to repeat the contain important business and financial information about us that is not included in or delivered with this prospectus. The information incorporated by reference is considered to be part of this prospectus, and later information that we file filed with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and as well as any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) from the date of the initial registration statement and prior to the effectiveness of the this registration statement, and (ii) any filings made after the date of this prospectus and before the completion of the offerings until we sell all of the securities included under this prospectus, except that we do not incorporate any document or portion of a document that is "furnished" to the SEC, but not deemed "filed." The following documents filed with the SEC are incorporated by reference in this prospectus. · Our annual report : • our Annual Report on Form 10-K for the fiscal year ended December 31January 2, 2017 2016 (including any portions of our Definitive Proxy Statement on Schedule 14A filed on May 2, 2016 that are incorporated by reference into such Annual Report on Form 10-K); • our Quarterly Reports on Form 10-Q for the quarters ended April 2, 2016 and July 2, 2016; • our Current Reports on Form 8-K filed on January 13, 2016, February 1, 2016, February 10, 2016, June 9, 2016 and August 2, 2016; and • the description of our common stock contained in our Registration Statement on Form 8-A filed with the SEC on February 22November 27, 2018 (File No2006, including any amendments or reports filed for the purpose of updating such description. 001-12584); · Our current reports We will provide without charge to each person, including any beneficial owner, to whom a prospectus is delivered, on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description written or oral request of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of chargethat person, a copy of any or all of these the documents (we are incorporating by reference into this prospectus, other than exhibits to these those documents unless the such exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxxthose documents. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.Such written requests should be addressed to:

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows permits us to “incorporate by reference” the information and reports we file with it which it. This means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusanother document. The information incorporated that we incorporate by reference is considered to be part of this prospectus, and later information that we file with the SEC will automatically update updates and supersede supersedes this information. We incorporate by reference the documents listed below below, except to the extent information in those documents is different from the information contained in this prospectus, and any all future filings made documents filed with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 14, or 15(d) of the Exchange Act after (i) other than the date of the initial registration statement and prior portions thereof deemed to be furnished to the effectiveness SEC pursuant to Item 9 or Item 12) until we terminate the offering of the registration statement, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · these securities: ● Our annual report Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2018, which was filed with the SEC on February 2228, 2018 2019; ● Our Quarterly Report on Form 10-Q for the quarter ended March 31, 2019, which was filed on May 5, 2019; ● Our Quarterly Report on Form 10-Q for the quarter ended June 30, 2019, which was filed on July 31, 2019; ● Our Quarterly Report on Form 10-Q for the quarter ended September 30, 2019, which was filed on November 12, 2019; ● Our Current Reports on Form 8-K, which were filed on January 1, 2019, January 17, 2019, January 28, 2019, January 31, 2019, February 15, 2019, March 29, 2019, May 10, 2019, July 7, 2019, August 5, 2019 and September 25, 2019 (File No. 001-12584); · Our current reports in each case excluding any information furnished pursuant to Item 2.02 or Item 7.01 of any such Current Report on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584unless otherwise indicated therein); and · ● The description of our common stock set forth in our registration statement on Form 8-A12B, which was filed onJuly 24, 2015, and any amendments or reports filed for the purpose of updating this description; and ● All documents we file with the SEC under Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus and prior to the termination of this offering made by way of this prospectus. To the extent that any statement in this prospectus is inconsistent with any statement that is incorporated by reference and that was made on June 20or before the date of this prospectus, 2007 (File Nothe statement in this prospectus shall supersede such incorporated statement. 000-12584)The incorporated statement shall not be deemed, except as modified or superseded, to constitute a part of this prospectus or the registration statement. Statements contained in this prospectus as to the contents of any contract or other document are not necessarily complete and, in each instance, we refer you to the copy of each contract or document filed as an exhibit to our various filings made with the SEC. You may obtain, free of charge, request a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) filings, at no cost, by writing or calling telephoning us at the following address and or telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.:

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows permits us to “incorporate by reference” the information contained in documents we file with it the SEC, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information rather than by including them in this prospectus. The information Information that is incorporated by reference is considered to be part of this prospectus and you should read it with the same care that you read this prospectus, and later . Later information that we file with the SEC will automatically update and supersede the information that is either contained, or incorporated by reference, in this informationprospectus, and will be considered to be a part of this prospectus from the date those documents are filed. We have filed with the SEC, and incorporate by reference the documents listed below following in this prospectus: · our Annual Report on Form 10-K for the year ended March 31, 2021, filed on July 14, 2021; · our Quarterly Report on Form 10-Q for the quarter ended June 30, 2021, filed on August 16, 2021; · our Current Reports on Form 8-K filed onJuly 6, 2021, July 9, 2021, July 20, 2021, July 30, 2021, and any future filings made August 2, 2021; · our Definitive Proxy Statement on Schedule 14A, as filed with the SEC (other than any portions of any such on July 29, 2021; and · our Registration Statement on Form 8-A as filed with the SEC on December 15, 2006. In addition, all documents that are not deemed “filed” under the Exchange Act in accordance we file with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act Act, after (i) the date of the initial registration statement of which this prospectus is a part and prior to the effectiveness of the registration statement, and (ii) statement as well as all such documents that we file with the SEC after the date of this prospectus and before the completion termination of the offerings offering of our securities shall be deemed incorporated by reference into this prospectus and to be a part of this prospectus from the respective dates of filing such documents. Unless specifically stated to the contrary, none of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports information that we disclose under Items 2.02 or 7.01 of any Current Report on Form 8-K (File No. 001-12584) filed with that we may from time to time furnish to the SEC on January 8will be incorporated by reference into, 2018or otherwise included in, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584)this prospectus. You may obtain, free of charge, request a copy of any or all of these the documents incorporated by reference but not delivered with this prospectus, at no cost, by writing or telephoning us at the following address and number: Investor Relations, Sonoma Pharmaceuticals, Inc., 000 Xxxxx Xxxx, Suite 150, Woodstock, Georgia, 30189, telephone (other than 000) 000-0000. We will not, however, send exhibits to these documents those documents, unless the exhibits are specifically incorporated by reference into these documents in those documents. Insofar as indemnification for liabilities arising under the Securities Act, as amended, may be permitted to directors, officers, and controlling persons of the registrant pursuant to the Company’s constituent documents, or referred otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer, or controlling person in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person connected with the securities being registered, we will, unless in the opinion of our counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in this prospectus) the Securities Act and will be governed by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000final adjudication of such issue.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows permits us to “incorporate by reference” the information and reports we file with it which it. This means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusanother document. The information incorporated that we incorporate by reference is considered to be part of this prospectusprospectus supplement, and later information that we file with the SEC will automatically update updates and supersede supersedes this information. We incorporate by reference the documents listed below below, except to the extent information in those documents is different from the information contained in this prospectus supplement, and any all future filings made documents filed with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 14, or 15(d) of the Exchange Act after (i) other than the date of the initial registration statement and prior portions thereof deemed to be furnished to the effectiveness SEC pursuant to Item 9 or Item 12) until we terminate the offering of the registration statement, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · these securities: ● Our annual report Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2019, which was filed with on March 11, 2020; ● Our Quarterly Report on Form 10-Q for the SEC quarter ended March 31, 2020, which was filed on February April 30, 2020; ● Our Quarterly Report on Form 10-Q for the quarter ended June 30, 2020, which was filed on August 4, 2020; ● Our Quarterly Report on Form 10-Q for the quarter ended September 30, which was filed on October 22, 2018 2020; ● the information specifically incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 from our Definitive Proxy Statement on Schedule 14A, filed on April 16, 2020; ● Our Current Reports on Form 8-K, which were filed on January 22, 2020, March 30, 2020, April 9, 2020, April 14, 2020, April 20, 2020, May 20, 2020, June 5, 2020, July 1, 2020, July 21, 2020, and February 17, 2021 (File No. 001-12584); · Our current reports in each case excluding any information furnished pursuant to Item 2.02 or Item 7.01 of any such Current Report on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584unless otherwise indicated therein); and · ● The description of our common stock set forth in our registration statement on Form 8-A12B, which was filed on July 24, 2015, and any amendments or reports filed for the purpose of updating this description; and ● All documents we file with the SEC under Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus and prior to the termination of this offering made by way of this prospectus. To the extent that any statement in this prospectus supplement is inconsistent with any statement that is incorporated by reference and that was made on June 20or before the date of this prospectus supplement, 2007 (File Nothe statement in this prospectus supplement shall supersede such incorporated statement. 000-12584)The incorporated statement shall not be deemed, except as modified or superseded, to constitute a part of this prospectus supplement or the registration statement. Statements contained in this prospectus supplement as to the contents of any contract or other document are not necessarily complete and, in each instance, we refer you to the copy of each contract or document filed as an exhibit to our various filings made with the SEC. You may obtain, free of charge, request a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) filings, at no cost, by writing or calling telephoning us at the following address and or telephone number: Synthetic BiologicsWe have filed with the SEC a registration statement under the Securities Act (SEC File No. 333-235238) that registers the securities offered hereby. The registration statement, Inc.including the exhibits and schedules attached thereto and the information incorporated by reference therein, 0000 Xxxxxxx Xxxxxx Xxxxxcontains additional relevant information about the securities and our Company, Xxxwhich we are allowed to omit from this prospectus supplement pursuant to the rules and regulations of the SEC. 000In addition, Xxxxxxxxxwe file annual, Xxxxxxxx quarterly and current reports and proxy statements and other information with the SEC. You may read and copy any document that we file at the SEC’s Public Reference Room at 000 X Xxxxxx, X.X., Xxxxxxxxxx, X.X. 00000. Our telephone number is (000) Please call the SEC at 0-000-0000XXX-0000 for further information on the Public Reference Room. Our SEC filings are also available on the SEC’s website at xxx.xxx.xxx. Copies of certain information filed by us with the SEC are also available on our website at xxx.xxxxxxxxxx.xxx. We have not incorporated by reference into this prospectus supplement the information on our website and it is not a part of this document.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows permits us to “incorporate by reference” the information contained in documents we file with it the SEC, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information rather than by including them in this prospectus. The information Information that is incorporated by reference is considered to be part of this prospectus and you should read it with the same care that you read this prospectus, and later . Later information that we file with the SEC will automatically update and supersede the information that is either contained, or incorporated by reference, in this informationprospectus, and will be considered to be a part of this prospectus from the date those documents are filed. We have filed with the SEC, and incorporate by reference the documents listed below following in this prospectus: · our Annual Report on Form 10-K for the year ended March 31, 2020, filed on July 10, 2020; · our Quarterly Report on Form 10-Q for the quarter endedJune 30, 2020, filed on August 14, 2020, the Amendment No. 1 to the Quarterly Report on Form 10-Q/A for the quarter ended June 30, 2020, filed on November 17, 2020; and any future filings made the Quarterly Report on Form 10-Q for the quarter endedSeptember 30, 2020, filed on November 20, 2020; · our Current Reports on Form 8-K filed on April 20, 2020; May 4, 2020; May 26, 2020; June 4, 2020; June 29, 2020; August 6, 2020; September 11, 2020; September 18, 2020; November 17, 2020; December 10, 2020; and December 17, 2020; · our Definitive Proxy Statement on Schedule 14A, as filed with the SEC (other than any portions of any such on July 29, 2021; and · our Registration Statement on Form 8-A as filed with the SEC onDecember 15, 2006. In addition, all documents that are not deemed “filed” under the Exchange Act in accordance we file with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities and Exchange Act of 1934, as amended, after (i) the date of the initial registration statement of which this prospectus is a part and prior to the effectiveness of the registration statement, and (ii) statement as well as all such documents that we file with the SEC after the date of this prospectus and before the completion termination of the offerings offering of our securities shall be deemed incorporated by reference into this prospectus and to be a part of this prospectus from the respective dates of filing such documents. Unless specifically stated to the contrary, none of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports information that we disclose under Items 2.02 or 7.01 of any Current Report on Form 8-K (File No. 001-12584) filed with that we may from time to time furnish to the SEC on January 8will be incorporated by reference into, 2018or otherwise included in, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584)this prospectus. You may obtain, free of charge, request a copy of any or all of these the documents incorporated by reference but not delivered with this prospectus, at no cost, by writing or telephoning us at the following address and number: Investor Relations, Sonoma Pharmaceuticals, Inc., 000 Xxxxx Xxxx, Suite 150, Woodstock, Georgia 30189, telephone (other than 000)000-0000. We will not, however, send exhibits to these documents those documents, unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000those documents.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” reference the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectus. The information incorporated by reference is considered to be part of this prospectus, and later information another document that we file have filed separately with the SEC will automatically update and supersede this informationSEC. We hereby incorporate by reference the following information or documents listed below into this prospectus: · our Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 31, 2022; · our Definitive Proxy Statement on Schedule 14A relating to our 2022 Annual Meeting of Stockholders, filed with the SEC on May 2, 2022; · our Definitive Information Statement on Schedule 14C, filed with the SEC on January 23, 2023; · our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2022, June 30, 2022 and September 30, 2022, filed with the SEC on May 16, 2022, August 15, 2022 and November 14, 2022, respectively; · our Current Reports on Form 8-K filed with the SEC on February 14, 2022, April 6, 2022, April 12, 2022, June 28, 2022, October 11, 2022, October 20, 2022, December 28, 2022, January 3, 2023, January 9, 2023 and January 27, 2023; and · the description of our Class A common stock contained in our Registration Statement on Form 8-A, filed with the SEC on January 25, 2022 under Section 12(b) of the Exchange Act, including any amendments or reports filed for the purpose of updating such description (including Exhibit 4.1 to our Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 31, 2022). Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information. We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statementAct, and (ii) the date of this prospectus and before the completion of the offerings until we sell all of the securities included offered by this prospectus. Information in such future filings updates and supplements the information provided in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC on February 22that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements. Upon written or oral request, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8we will provide to you, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of without charge, a copy of any or all of these the documents (other than that are incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits to these documents unless the exhibits which are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone numbersuch documents. Requests should be directed to: Synthetic BiologicsKnightscope, Inc., Attention: Investor Relations, 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, XxxxxxxxxXxxxx Xxxxx Xxxxxx, Xxxxxxxx Xxxx, Xxxxxxxxxx 00000. Our , telephone number is (000) 000-0000. We may, from time to time in one or more offerings, offer and sell up to $100,000,000 in the aggregate of Class A common stock, preferred stock, debt securities, warrants and units, in any combination. The specific terms of the securities, including their offering prices, will be contained in one or more supplements to this prospectus. You should read this prospectus and any prospectus supplement carefully before you invest. The securities may be sold to or through one or more underwriters, dealers or agents, or directly to investors, on a continuous or delayed basis. See “Plan of Distribution.” Our Class B common stock is not publicly traded. Holders of Class A common stock and holders of Class B common stock have substantially identical rights, except that holders of Class A common stock are entitled to one vote per share and holders of shares of Class B common stock are entitled to 10 votes per share. Holders of Class A common stock and holders of Class B common stock vote together as a single class on all matters submitted to a vote of stockholders, unless otherwise required by law or our certificate of incorporation. Each share of Class B common stock may be converted into a share of Class A common stock at any time at the election of the holder. See “Description of Capital Stock.” Our Class A common stock is traded on The Nasdaq Global Market under the symbol “KSCP.” On January 30, 2023, the last reported sales price of our Class A common stock on The Nasdaq Global Market was $1.60 per share. We are an “emerging growth company” as defined under U.S. federal securities laws and, as such, have elected to comply with reduced public company reporting requirements. This prospectus complies with the requirements that apply to an issuer that is an emerging growth company. As of January 27, 2023, the aggregate market value of our outstanding Class A common stock held by non-affiliates, or public float, was approximately $60.7 million, based on the closing price of our Class A common stock as reported on The Nasdaq Global Market on December 5, 2022, as calculated in accordance with General Instruction I.B.6 of Form S-3. We have not sold any securities pursuant to General Instruction I.B.6. of Form S-3 during the 12 calendar months prior to and including the date of this prospectus. Pursuant to General Instruction I.B.6 of Form S-3, in no event will we sell any securities in a public primary offering with a value exceeding one-third of our public float in any 12-month period unless our public float subsequently rises to $75.0 million or more. Investing in our securities involves risks. See “Risk Factors” on page 1 of this prospectus, and any applicable prospectus supplement, and in the documents that are incorporated by reference herein and therein. Page ABOUT THIS PROSPECTUS ii RISK FACTORS 1 CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS iii USE OF PROCEEDS 1 OUR COMPANY 2 DESCRIPTION OF DEBT SECURITIES 8 DESCRIPTION OF CAPITAL STOCK 2 DESCRIPTION OF UNITS 15 DESCRIPTION OF WARRANTS 14 LEGAL MATTERS 18 PLAN OF DISTRIBUTION 16 WHERE YOU CAN FIND MORE INFORMATION 18 EXPERTS 18 INFORMATION INCORPORATED BY REFERENCE 18 This prospectus is part of a registration statement on Form S-3 under the Securities Act of 1933, as amended (the “Securities Act”), that we filed with the Securities and Exchange Commission (“SEC”) using the “shelf” registration process. Under this shelf registration process, we may offer and sell any combination of the securities described in this prospectus in one or more offerings, up to a total dollar amount of $100,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we offer the securities described in this prospectus, we will provide you with a prospectus supplement that will describe the specific amounts, prices and terms of the securities being offered. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement or free writing prospectus may also add, update or change information contained in or incorporated by reference into this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or free writing prospectus, you should rely on the prospectus supplement or free writing prospectus, as applicable. This prospectus does not contain all the information provided in the registration statement filed with the SEC. You should carefully read both this prospectus and any prospectus supplement (and any applicable free writing prospectuses), together with the additional information described below under “Where You Can Find More Information” and “Information Incorporated By Reference” before you make an investment decision. We have not authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus or in any prospectus supplement or free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. You should assume that the information appearing in this prospectus and the applicable prospectus supplement to this prospectus is accurate as of the date on its respective cover and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. Any statement made in this prospectus or in a document incorporated or deemed to be incorporated by reference in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in a prospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. See “Information Incorporated By Reference.” This prospectus and any accompanying prospectus supplements may include trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included in this prospectus or any accompanying prospectus supplement are the property of their respective owners.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information that is incorporated by reference is considered to be part of this prospectusprospectus supplement, and later the information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made we make with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections Section 13(a), 13(c), 14 14, or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date termination of this prospectus offering and before the completion following documents (other than information in documents that is deemed not to be filed, including the portions of the offerings these documents that are furnished under items 2.02 or Item 7.01 of the securities a Current Report on Form 8-K, including any exhibits included in this prospectus. · Our annual report with such Items): ● our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2023, filed with the SEC on February 22March 29, 2018 (File No. 0012024; ● our Proxy Statement on Schedule 14A for our Annual Meeting of Stockholders, filed April 29, 2024; ● our Quarterly Report on Form 10-12584)Q for the quarter ended March 31, 2024, filed on May 10, 2024; · Our current reports ● our Current Reports on Form 8-K (File No. 001-12584) K, filed with the SEC on January 818, 20182024, March 7January 25, 2018; April 232024, 2018 January 30, 2024, February 6, 2024 and May 721, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584)2024; and · The ● the description of our common stock set forth contained in or incorporated into our registration statement Registration Statement on Form 8-A12BA, filed with September 17, 2020, and any amendment or report updating that description. Notwithstanding the SEC on June 20foregoing, 2007 (File No. 000-12584). You may obtain, free of charge, a copy documents or portions thereof containing information furnished under Items 2.02 and 7.01 of any of these documents (other than Current Report on Form 8-K, including the related exhibits to these documents unless the exhibits under Item 9.01, are specifically not incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us the Company to “incorporate by reference” the information we file it files with it the SEC, which means that we the Company can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information incorporated by reference is considered to be an important part of this prospectusOffer to Purchase. Any statement contained in a document which is incorporated by reference in this Offer to Purchase is automatically updated and superseded if information contained in this Offer to Purchase, or information that the Company later filed with the SEC, modifies or replaces this information. The Company incorporates by reference the following documents it filed with the SEC: • its Indenture, dated as of April 2, 2007, among the operating partnership, as issuer, the Company, as guarantor, and later information that we file U.S. Bank National Association, as trustee, including the form of 3.250% Exchangeable Senior Notes due 2012 (incorporated by reference to Exhibit 4.1 of Xxxxxx Realty Corporations’ Current Report on Form 8-K filed with the SEC will automatically update on April 5, 2007); • its Current Reports on Form 8-K filed on January 28, 2010, February 2, 2010, February 3, 2010, March 1, 2010, April 20, 2010 and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a)first Current Report on Form 8-K filed on April 14, 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · Our annual report 2010; • its Annual Report on Form 10-K for the fiscal year ended December 31, 2017 filed 2009; and • its Quarterly Report on Form 10-Q for the quarter ended March 31, 2010. The Company is not incorporating by reference any documents or portions thereof or exhibits thereto specifically listed above that are deemed “not filed” with the SEC SEC, including its compensation committee reports and performance graph included or incorporated by reference in any Annual Report on February 22, 2018 (File No. 001Form 10-12584); · Our current reports on K or any information or related exhibits furnished pursuant to Items 2.02 or 7.01 of Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, K. To receive a free of charge, a copy of any of these the documents (other than exhibits incorporated by reference in this Offer to these documents unless the exhibits Purchase, including exhibits, if they are specifically incorporated by reference into these documents in the documents, call or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologicswrite Xxxxxx Realty Corporation, Inc.00000 Xxxx Xxxxxxx Xxxxxxxxx, 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. Xxxxx 000, XxxxxxxxxXxx Xxxxxxx, Xxxxxxxx Xxxxxxxxxx 00000. Our telephone number is , Attention: Secretary, (000) 000-0000. In order to tender, a holder must mail or deliver, or cause to be mailed or delivered, a properly completed and signed Letter of Transmittal and any other required documents to the depositary at its address set forth below or tender through DTC’s ATOP by transmitting their acceptance to DTC in accordance with DTC’s ATOP procedures. A holder tendering notes through ATOP does not need to complete the Letter of Transmittal. Table of Contents The depositary for the offer is: Any questions or requests for assistance may be directed to the dealer managers or the information agent at their respective telephone numbers as set forth below. Any requests for additional copies of this Offer to Purchase, the Letter of Transmittal or related documents may be directed to the information agent. A holder may also contact such holder’s broker, dealer, commercial bank, trust company or other nominee for assistance concerning the offer. The information agent for the offer is: Table of Contents [Attached] Table of Contents Confirm receipt by calling: (000) 000-0000 Xxxxxx Realty, L.P., or the operating partnership, is a Delaware limited partnership. Xxxxxx Realty Corporation, or the Company, is a Maryland corporation and the sole general partner of the operating partnership. Unless otherwise expressly stated or the context otherwise requires, in this Offer to Purchase “we,” “us” and “our” refer to the Company, the operating partnership and the Company’s other subsidiaries. We are offering (the “offer”) to purchase for cash any and all of its outstanding 3.250% Exchangeable Senior Notes due 2012 (the “notes”) from the registered holders thereof (the “holders”), upon the terms and subject to the conditions described in the Offer Documents. Table of Contents Capitalized terms used herein and not defined herein have the meaning given to them in the Offer to Purchase. This Letter of Transmittal is to be completed by a holder desiring to tender notes pursuant to the offer unless such holder is executing the tender through ATOP. A holder tendering notes through ATOP does not need to complete this Letter of Transmittal. Holders that are tendering notes by book-entry transfer to the depositary’s account at DTC can execute the tender through ATOP. DTC participants that are accepting the offer must transmit their acceptance to DTC, which will verify the acceptance and execute a book-entry delivery to the depositary’s account at DTC. DTC will then send an Agent’s Message to the depositary for its acceptance. Delivery of the Agent’s Message by DTC will satisfy the terms of the offer as to execution and delivery of a Letter of Transmittal by the participant identified in the Agent’s Message. Table of Contents ¨ CHECK HERE IF CERTIFICATES REPRESENTING TENDERED NOTES ARE ENCLOSED HEREWITH. ¨ CHECK HERE IF TENDERED NOTES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER MADE TO THE ACCOUNT MAINTAINED BY THE DEPOSITARY WITH DTC AND COMPLETE THE FOLLOWING: Name of Tendering Institution: Account Number: Transaction Code Number: Date Tendered: List below the notes to which this Letter of Transmittal relates. If the space provided is inadequate, list the principal amounts on a separately executed schedule and affix the schedule to this Letter of Transmittal. Tenders of notes will be accepted only in principal amounts equal to $1,000 or integral multiples thereof. No alternative, conditional or contingent tenders will be accepted. * Need not be completed by holders tendering notes by book-entry transfer. ** Unless otherwise specified, it will be assumed that the entire aggregate principal amount represented by the notes described above is being tendered. See Instruction 3. If tendered by a participant in DTC, and if not already printed above, the participant name(s) and address(es) should be printed exactly as such participant’s name appears on a security position listing as the owner of the notes. The offer is not being made to, and tenders will not be accepted from or on behalf of, holders in any jurisdiction in which the making or the acceptance of the offer would not be in compliance with the laws of such jurisdiction. The payment date for a holder that validly tenders and does not validly withdraw its notes prior to the expiration time and whose notes are accepted for purchase by us is expected to occur on Friday, June 18, 2010. Such a holder will receive the purchase price payable for its notes, plus accrued and unpaid interest to, but not including, the payment date. We may, in our sole discretion, extend the expiration time to a date and time later than 5:00 p.m., New York City time, Tuesday, June 15, 2010. Table of Contents Ladies and Gentlemen: The undersigned hereby tenders to the operating partnership, upon the terms and subject to the conditions set forth in the Offer to Purchase, receipt of which is hereby acknowledged, and in accordance with this Letter of Transmittal, the principal amount of the notes indicated in the table above entitled “Description of Notes Tendered” under the column heading “Aggregate Principal Amount Tendered” (or, if nothing is indicated therein, with respect to the entire aggregate principal amount represented by the notes described in such table). The undersigned acknowledges and agrees that the tender of notes made hereby may not be withdrawn except to the extent required by law or in accordance with the procedures set forth in the Offer to Purchase. Subject to, and effective upon, the acceptance for purchase of, and payment for, the principal amount of notes tendered with this Letter of Transmittal in accordance with the terms and subject to the conditions of the offer, the undersigned hereby (a) sells, assigns and transfers to, or upon the order of, the operating partnership, all right, title and interest in and to all of the notes tendered hereby, (b) waives any and all other rights with respect to such notes (including, without limitation, any existing or past defaults and their consequences in respect of such notes and the indenture governing such notes) and (c) releases and discharges the operating partnership from any and all claims the undersigned may have now or may have in the future arising out of or related to the notes, including, without limitation, any claims that the undersigned is entitled to participate in any repurchase, redemption or defeasance of the notes. The undersigned hereby irrevocably constitutes and appoints the depositary as the true and lawful agent and attorney-in-fact of the undersigned (with full knowledge that the depositary also acts as the agent of the operating partnership) with respect to such notes, with full powers of substitution and revocation (such power of attorney being deemed to be an irrevocable power coupled with an interest), to: • present such notes and all evidences of transfer and authenticity to, or transfer ownership of such notes on the account books maintained by DTC and the trustee to, or upon the order of, the operating partnership, • present such notes for transfer of ownership on the books of the operating partnership, and • receive all benefits and otherwise exercise all rights of beneficial ownership of such notes, all in accordance with the terms and conditions of the offer as described in this Letter of Transmittal and in the Offer to Purchase. The undersigned acknowledges and agrees that a tender of notes pursuant to any of the procedures described in the Offer to Purchase and in the instructions to this Letter of Transmittal and an acceptance of such notes by the operating partnership will constitute a binding agreement between the undersigned and the operating partnership upon the terms and subject to the conditions of the offer, which agreement shall be governed by, and construed in accordance with, the laws of the State of New York. The undersigned acknowledges, by tendering notes pursuant to any of the procedures described in the Offer to Purchase and in the instructions to this Letter of Transmittal, under certain circumstances set forth in the Offer to Purchase, the operating partnership is not required to accept for purchase any of the notes tendered. The undersigned hereby represents and warrants that (a) the undersigned has read the Offer to Purchase and this Letter of Transmittal and agrees to all of the terms and conditions of the offer, (b) the undersigned has full power and authority to tender, sell, assign and transfer the notes tendered hereby, and (c) when such tendered notes are accepted for purchase and payment by the operating partnership pursuant to the offer, the operating partnership will acquire good title thereto, free and clear of all liens, restrictions, charges and encumbrances and not subject to any adverse claim or right. The undersigned will, upon request, execute and deliver any additional documents deemed by the depositary or by the operating partnership to be necessary or desirable to complete the sale, assignment and transfer of the notes tendered hereby.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusprospectus supplement. The information incorporated by reference is considered to be part of this prospectusprospectus supplement, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus supplement and before the completion of the offerings of the securities shares of our common stock included in this prospectusprospectus supplement. · Our annual report Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2019 filed with the SEC on February 22onFebruary 20, 2018 2020 (File No. 001-12584); · Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020, June 30, 2020 and September 30, 2020 filed with the SEC onMay 5, 2020, August 6, 2020 and November 10, 2020 and our Quarterly Report on Form 10-Q/A filed with the SEC onNovember 12, 2020; · Our current reports on Form 8-K and Form 8-K/A (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 232020, 2018 and May February 7, 20182020, August 5, 2020, September 18, 2020, October 2, 2020, November 12, 2020, November 17, 2020, November 18, 2020, November 24, 2020, December 22, 2020, December 31, 2020, January 6, 2021, January 19, 2021, January 27, 2021, January 29, 2021 and February 1, 2021; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18onAugust 4, 2017 2020 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June onJune 20, 2007 (File No. 000-12584), as updated by the description of our common stock filed as Exhibit 4.16 to our Annual Report on Form 10-K for the year ended December 31, 2019, including any amendments or reports filed for the purpose of updating such description. You may obtainAny statement contained in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus supplement modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, free except as so modified or superseded, to constitute a part of chargethis prospectus supplement. We will furnish without charge to you, on written or oral request, a copy of any or all of these the documents (other than that are incorporated by reference into this prospectus supplement and the accompanying base prospectus but not delivered with the prospectus supplement, including exhibits to these documents unless the exhibits which are specifically incorporated by reference into these such documents. You should direct any requests for documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., Attn: Xxxxxx X. Xxxxxxxxxx, Chief Executive Officer and Chief Financial Officer, 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. Xxxxx 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is , or telephoning us at (000) 000-0000. You should rely only on information contained in, or incorporated by reference into, this prospectus supplement and the accompanying base prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus supplement or incorporated by reference in this prospectus supplement or the accompanying base prospectus. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation. We may offer and sell up to $200,000,000 in the aggregate of the securities identified above from time to time in one or more offerings. This prospectus provides you with a general description of the securities. Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement before you invest in any of our securities. We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities. Our common stock is listed on the NYSE American LLC under the symbol “SYN.” The last reported sale price of our common stock on the NYSE American LLC on May 3, 2018 was $0.23 per share. We urge prospective purchasers of our common stock to obtain current information about the market prices of our common stock. On February 22, 2018, the date we filed our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, we became subject to the offering limits in General Instruction I.B.6 of Form S-3. As of the date of this prospectus, the aggregate market value of our common stock held by non-affiliates pursuant to General Instruction I.B.6 of Form S-3 is $44,622,699, which is calculated based on 114,799,845 shares of our common stock outstanding held by non-affiliates and a price of $0.3887 per share, the closing price of our common stock on March 16, 2018, which is the highest closing sale price of our common stock on the NYSE American LLC within the prior 60 days of this prospectus. During the prior 12 calendar month period that ends on and includes the date hereof, we have not offered or sold any shares of our common stock pursuant to General Instruction I.B.6 to Form S-3. About this Prospectus i Ratio of Earnings to Fixed Charges and Preferred Stock Dividends 9 This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, (the “SEC”), using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time and in one or more offerings up to a total dollar amount of $200,000,000 of securities as described in this prospectus. We have provided to you in this prospectus a general description of the securities we may offer. Each time that we offer and sell securities under this shelf registration statement, we will, to the extent required by law, provide a prospectus supplement to this prospectus that will contain specific information about the securities being offered and sold and the specific terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or any free writing prospectus, you should rely on the prospectus supplement or free writing prospectus; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus or any prospectus supplement or any related free writing prospectus — the statement in the document having the later date modifies or supersedes the earlier statement. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement, together with the additional information described under the heading “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” Unless otherwise stated or the context otherwise requires, references in this prospectus to “Synthetic” the “Company,” “we,” “our” and “us” refer to Synthetic Biologics, Inc., a Nevada corporation, and its consolidated subsidiaries, unless otherwise specified. When we refer to “you,” we mean the holders of the applicable series of securities.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information that is incorporated by reference is considered to be part of this prospectus, and later the information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus the documents listed below and any future filings made following documents: · our Annual Report on Form 10-K for the year ended December 31, 2019, filed with the SEC on March 13, 2020, including the information specifically incorporated by reference therein from our definitive proxy statement for our 2020 annual meeting of stockholders; · our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2020, filed on May 6, 2020; for the quarter ended June 30, 2020, filed on August 5, 2020; and for the quarter ended September 30, 2020, filed on November 5, 2020; · our Current Reports on Form 8-K filed with the SEC on January 7, 2020, February 7, 2020, February 11, 2020 (other than both reports), February 24, 2020, March 5, 2020, March 20, 2020, April 3, 2020, April 21, 2020, April 28, 2020, May 1, 2020, May 21, 2020, May 27, 2020, June 18, 2020, July 6, 2020, and September 3, 2020 (provided that any portions of any such documents reports that are deemed furnished and not deemed “filed” under filed pursuant to instructions to Form 8-K shall not be incorporated by reference into this prospectus); and · the description of our common stock set forth in our Registration Statement on Form 8-A12B filed with the SEC on November 5, 2014 pursuant to Section 12(b) of the Exchange Act in accordance Act, including any amendment or report filed for the purpose of updating such description, including Exhibit 4.7 to our Annual Report on Form 10-K for the fiscal year ended December 31, 2019, as filed with the Exchange Act and applicable SEC rules) on March 13, 2020. All documents subsequently filed with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after prior to the termination of this offering shall be deemed to be incorporated by reference into this prospectus. Any statement contained in any document incorporated by reference herein will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or any additional prospectus supplements modifies or supersedes such statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We may offer from time to time in one or more offerings up to an aggregate of $200,000,000 of the common stock, preferred stock, debt securities, warrants or units described in this prospectus, separately or together in one or more combinations. The preferred stock, debt securities, and warrants may be convertible into or exercisable or exchangeable for common stock or preferred stock or other securities, as identified in the applicable prospectus supplement. This prospectus provides a general description of the securities we may offer. This prospectus will allow us to offer for sale securities over time. Each time we sell securities, we will provide specific terms of the securities offered in the applicable prospectus supplement. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference herein and therein, before you invest in any of our securities. This prospectus may not be used to sell the securities unless accompanied by a prospectus supplement. We may offer and sell the securities through underwriters, dealers or agents, or directly to purchasers, or through a combination of these methods. See “Plan of Distribution” beginning on page 14 of this prospectus. Our common stock is listed on the Nasdaq Capital Market under the symbol “ADMA.” On October 1, 2019, the last reported sale price of our common stock was $4.45 per share. This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission (ithe “SEC” or the “Commission”) using a “shelf” registration process under the Securities Act of 1933, as amended (the “Securities Act”). Under this shelf registration process, we may offer and sell, from time to time, any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $200,000,000. This prospectus provides a general description of the securities we may offer. Each time we sell the securities, we will, to the extent required by law, provide a prospectus supplement that will contain specific information about the terms of the offering. We may also authorize one or more free writing prospectuses to be provided to you in connection with the offering. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. You should carefully read this prospectus, the applicable prospectus supplement, and any applicable free writing prospectus, as well as the information and documents incorporated herein and therein by reference and the additional information under the heading “Where You Can Find More Information,” before making an investment decision. We have not authorized any dealer, salesman or other person to give any information or to make any representation other than those contained in, or incorporated by reference into, this prospectus and the applicable prospectus supplement, and any free writing prospectus we have authorized for use in connection with a specific offering. This prospectus and any accompanying prospectus supplement to this prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor do this prospectus or any accompanying prospectus supplement to this prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus, any accompanying prospectus supplement and any applicable free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the initial registration statement and prior document incorporated by reference, even though this prospectus, any accompanying prospectus supplement or any applicable free writing prospectus is delivered, or securities sold, on a later date. This prospectus may not be used by us to consummate sales of our securities unless it is accompanied by a prospectus supplement. To the effectiveness of the registration statementextent there are inconsistencies between any prospectus supplement, and (ii) the date of this prospectus and before any documents incorporated by reference, the completion of the offerings of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed document with the SEC on February 22most recent date will control. This prospectus includes our trademarks, 2018 (File Notrade names and service marks, such as “ASCENIV™,” “Nabi-HB®” and “BIVIGAM®,” which are protected under applicable intellectual property laws and are the property of ADMA Biologics, Inc., or its subsidiaries. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8Solely for convenience, 2018trademarks, March 7, 2018; April 23, 2018 trade names and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of charge, a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or service marks referred to in this prospectus) by writing prospectus may appear without the ®, ™ or calling SM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the right of the applicable licensor to these trademarks, trade names and service marks. We do not intend our use or display of other parties’ trademarks, trade names or service marks to imply, and such use or display should not be construed to imply, a relationship with, or endorsement or sponsorship of us at by, these other parties. Unless the following address context otherwise requires, references in this prospectus to “we,” “us,” “our,” the “Company,” “ADMA Biologics” and telephone number: Synthetic “ADMA” refer to ADMA Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxxa Delaware corporation, Xxxand its subsidiaries: ADMA Plasma Biologics, Inc., a Delaware corporation (“ADMA Plasma”), ADMA Bio Centers Georgia Inc., a Delaware corporation (“ADMA BioCenters”), and ADMA BioManufacturing, LLC, a Delaware limited liability company (“ADMA BioManufacturing”). 000ADMA Biologics, XxxxxxxxxInc. is a vertically integrated commercial biopharmaceutical and specialty immunoglobulin company that manufactures, Xxxxxxxx markets and develops specialty plasma-derived biologics for the treatment of immune deficiencies and the prevention and treatment of certain infectious diseases. Our targeted patient populations include immune-compromised individuals who suffer from an underlying immune deficiency disorder or who may be immune-suppressed for medical reasons. We currently have three products with United States Food and Drug Administration (the “FDA”) approvals: Nabi-HB (Hepatitis B Immune Globulin, Human), which is currently marketed and commercially available and is indicated for the treatment of acute exposure to blood containing Hepatitis B surface antigen (“HBsAg”), and other listed exposures to Hepatitis B; ASCENIV (Immune Globulin Intravenous, Human – slra 10% Liquid), previously referred to as RI-002, an Intravenous Immune Globulin (“IVIG”) product for the treatment of Primary Humoral Immunodeficiency Disease (“PIDD” or “PI”), for which we received FDA approval on April 1, 2019 and anticipate having this product available for commercial launch in the second half of 2019; and BIVIGAM (Immune Globulin Intravenous, Human), for which we submitted a Prior Approval Supplement (the “PAS”) to the FDA to amend the approved Biologics License Application (“BLA”) to allow for the commercial re-launch of the product, which is indicated for the treatment of primary humoral immunodeficiency. The PAS was approved on May 9, 2019, and the commercial relaunch and first commercial sales of BIVIGAM were announced in August 2019. The raw material plasma we collect and procure to manufacture ASCENIV™ using our proprietary microneutralization assay contains plasma from donors with high titers to Respiratory Syncytical Virus. This plasma amounts to less than ten percent of the total donor collections from each center. We seek to develop a pipeline of plasma-derived therapeutics, including a product based on our most recently approved patent application under U.S. Patent No. 10,259,865 related to methods of treatment and prevention of S. pneumonia infection for an immunoglobulin manufactured to contain standardized antibodies to numerous serotypes of S. pneumonia. Our products and product candidates are intended to be used by physician specialists focused on caring for immune-compromised patients with or at risk for certain infectious diseases. ADMA Biologics, Inc. was founded on June 24, 2004 as a New Jersey corporation and re-incorporated in Delaware on July 16, 2007. We operate through our wholly- owned subsidiaries ADMA BioManufacturing, ADMA Plasma Biologics and ADMA BioCenters. ADMA BioManufacturing was formed in January 2017 to facilitate the acquisition (the “Biotest Transaction”) of certain assets of the Therapy Business Unit of Biotest Pharmaceuticals Corporation (“BPC” and, together with Biotest AG, “Biotest”). ADMA BioCenters is the Company’s source plasma collection business, which operates in the United States. Each operational biocenter, once approved, will have a license with the FDA and may obtain additional certifications from other regulatory agencies such as the German Health Authority and the Korean Ministry of Food and Drug Safety. ADMA BioCenters supplies ADMA with a portion of its raw material plasma for the manufacture of its products and product candidates. We maintain our headquarters at 000 Xxxxx Xxxxx 00, Xxxxxx, XX 00000. Our telephone number is (000) 000-0000. Our Florida campus is located at 0000 Xxxx xx Xxxxxxxx Xxxxxxxxx, Xxxxxxxxx, Xxxx Xxxxx, XX 00000. Our Florida telephone number is (000) 000-0000. We maintain a website at xxx.xxxxxxxxxxxxx.xxx. The information on, or that can be accessed through, our website is not part of this prospectus or any accompanying prospectus supplement or related free writing prospectus.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC Commission allows us to “incorporate by reference” the information we file with it the Commission, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information incorporated we incorporate by reference is considered to be an important part of this prospectus, and later certain information that we will later file with the SEC Commission will automatically update and supersede this information. We incorporate by reference the documents listed below and as well as any future filings made we make with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Commission pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding, unless otherwise provided therein or herein, documents not deemed “filed” with the Commission and information furnished pursuant to Item 2.02 and Item 7.01 on any Current Report on Form 8-K or certain exhibits furnished pursuant to Item 9.01 of Form 8-K) after (i) the date of the initial registration statement and prior to the effectiveness of the this registration statement, and (ii) any filings made after the date of this prospectus and before the completion of the offerings until we sell all of the securities included under this prospectus. The following documents filed with the Commission are incorporated by reference in this prospectus. · Our annual report : ● our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584)2021; · Our current reports ● our Current Reports on Form 8-K (File No. 001-12584) filed with the SEC Commission on January 8February 24, 20182022, March 731, 20182022; and April 234, 2018 2022 (other than Items 2.02 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-125849.01); ● our Defintive Proxy Statement, filed on April 29, 2022, for our Annual Meeting of Stockholders scheduled to be held on June 30, 2022; and · The ● the description of our common stock set forth included in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 A12B (File No. 000001-12584)33357) filed with the Commission on March 9, 2007, including any amendment or reports filed for the purpose of updating such description. You Copies of these filings are available at no cost on our website, xxx.xxxxxxxx.xxx. In addition, you may obtain, free of charge, request a copy of these filings and any of these documents (other than amendments thereto at no cost, by writing or telephoning us. Those copies will not include exhibits to these those documents unless the exhibits are specifically incorporated by reference into these in the documents or referred unless you specifically request them. You may also request copies of any exhibits to the registration statement at no cost. Please direct your request to: You should rely only on the information in this prospectus) , any prospectus supplement, any applicable free writing prospectus and the documents that are incorporated by reference. We have not authorized anyone else to provide you with different information. We are not offering these securities in any state where the offering is prohibited by law. You should not assume that the information in this prospectus, any prospectus supplement, any applicable free writing prospectus or calling us at any incorporated document is accurate as of any date other than the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000date of the document.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. We file or furnish annual and current reports and other information with the SEC (File Number 001-36187). These filings and other submissions contain important information that does not appear in this prospectus supplement. The SEC allows us to “incorporate by reference” the information we file with it in this prospectus supplement, which means that we can disclose important information to you by referring you to those other documents instead of having that we have filed or furnished with or to repeat the information in this prospectus. The SEC and such information incorporated by reference is then considered to be part of this prospectus, and later information that we file with the SEC will automatically update and supersede this informationprospectus supplement. We incorporate by reference in this prospectus the documents listed below and any future filings made with the SEC (other than any portions of any all amendments or supplements to such documents that are not deemed “filed” under we may file or furnish to the Exchange Act in accordance with the Exchange Act and applicable SEC rulespursuant to Section 13(a) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date Act: • Our 2019 annual report; • The description of the initial registration statement and prior to the effectiveness of the registration statementour ordinary shares contained in Form 8-A, and (ii) the date of this prospectus and before the completion of the offerings of the securities included in this prospectus. · Our annual report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584); · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B36187, filed with the SEC on June 20December 29, 2007 2016, as amended by Exhibit 2.1 to our 2019 annual report; and • Our Reports of Foreign Private Issuer on Form 6-K furnished to the SEC on May 6, 2020, May 26, 2020 (File Norelating solely to the consolidated statements of financial position tables for the quarter ended March 31, 2020 contained in the press release attached as exhibit 99.1 thereto), May 28, 2020, August 5, 2020 (excluding the statements of our President and CEO contained in the press release attached as exhibit 99.1 thereto), August 5, 2020, September 1, 2020, September 2, 2020, September 8, 2020 (excluding the statements of Biomica’s chairman and CEO contained in Exhibit 99.1 therein), September 10, 2020, September 15, 2020, October 13, 2020 (excluding the statements of Biomica’s chairman and CEO contained in Exhibit 99.1 therein), October 29, 2020 (excluding the statements of Xxxxx Bio’s chairman and CEO contained in Exhibit 99.1 therein), October 30, 2020 (other than Exhibit 99.1 therein), November 18, 2020 (excluding the statements of our President and CEO contained in Exhibit 99.1 therein), December 10, 2020, December 15, 2020 (excluding the statements of AgPlenus’ CEO and our President and CEO contained in Exhibit 99.1 therein and the video referenced therein), December 23, 2020, (excluding the statements of Xxxxxxx’s CEO and our President and CEO contained in Exhibit 99.1 therein), December 29, 2020 (excluding the statements of Xxxxx Bio’s CEO and our President and CEO contained in Exhibit 99.1 therein), December 31, 2020 and January 14, 2021. 000-12584). You may obtainWe will provide to each person, free of including any beneficial owner, to whom a prospectus is delivered, without charge, upon written or oral request, a copy of any or all of these documents (the information that has been incorporated by reference in this prospectus supplement, other than exhibits to these such documents unless the exhibits which are not specifically incorporated by reference into such documents. Please direct your written or telephone requests to our headquarters, which are currently located at 00 Xxx Xxxxxxxxx Street, Park Rehovot, P.O.B 4173, Xxxx Xxxxx, 7414002, Israel, Attn: VP Legal Affairs & Company Secretary, telephone number: +000-0-0000-000. Copies of these documents filings and submissions may also be accessed at our website, xxxxx://xxx.xxxxxxx.xxx. Information contained in our website is not part of this prospectus supplement. We may offer, issue and sell from time to time, in one or referred more offerings, up to $50,000,000, in the aggregate, of our ordinary shares, warrants to purchase ordinary shares, rights and units comprised of, or other combinations of, the foregoing securities. We refer to the ordinary shares, warrants, rights and units individually and collectively as “securities” in this prospectus) . Each time we sell securities, we will provide a supplement to this prospectus that contains specific information about the offering, as well as the amounts, prices and terms of the securities. We may also authorize one or more free writing prospectuses to be provided to you in connection with each offering of the securities. Any prospectus supplement and related free writing prospectuses may also add, update or change information contained in this prospectus. You should read this prospectus, any applicable prospectus supplement and related free writing prospectuses, as well as the documents incorporated by reference or deemed incorporated by reference into this prospectus, before you invest in any of our securities. We may, from time to time, offer and sell securities through public or private transactions, directly or through underwriters, agents or dealers, on or off the Nasdaq Stock Market, or Nasdaq, or Tel Aviv Stock Exchange Ltd., or the TASE, as applicable, at prevailing market prices or at privately negotiated prices. If any underwriters, agents or dealers are involved in the sale of any of these securities, the applicable prospectus supplement will set forth the names of the underwriters, agents or dealers and any applicable fees, commissions or discounts. Our net proceeds from the sale of securities will also be set forth in the applicable prospectus supplement. Our ordinary shares are traded on the Nasdaq and TASE under the symbol “EVGN.” On July 30, 2020, the closing price of our ordinary shares was $1.06 as reported on the Nasdaq. On June 23, 2020, the aggregate market value of our ordinary shares held by non-affiliates was approximately $31,124,387 based on 24,127,432 ordinary shares outstanding and a per ordinary share price of $1.29 based on the closing sale price of our shares on June 23, 2020. In addition, as of the date hereof, we have not offered any securities pursuant to General Instruction I.B.5 on Form F-3 during the prior 12 calendar month period that ends on and includes the date of this prospectus. ABOUT THIS PROSPECTUS 2 RISK FACTORS 3 FORWARD-LOOKING STATEMENTS 4 OUR COMPANY 5 CAPITALIZATION 5 USE OF PROCEEDS 5 DESCRIPTION OF SECURITIES 5 DESCRIPTION OF ORDINARY SHARES 6 DESCRIPTION OF WARRANTS 10 DESCRIPTION OF RIGHTS 11 DESCRIPTION OF UNITS 12 RESEARCH GRANTS 13 PLAN OF DISTRIBUTION 15 LEGAL MATTERS 18 EXPERTS 18 WHERE YOU CAN FIND MORE INFORMATION 18 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE 18 ENFORCEABILITY OF CIVIL LIABILITIES 19 OFFERING EXPENSES 20 This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, or the SEC, using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time, in one or more offerings up to a total dollar amount of $50,000,000, as described in this prospectus. Each time that we sell securities, we will provide a prospectus supplement to this prospectus that contains specific information about the securities being offered and sold and the specific terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you in connection with each offering of the securities. Any prospectus supplement and related free writing prospectuses may also add, update or calling change information contained in this prospectus. If there is any inconsistency between the information in this prospectus and in the applicable prospectus supplement or related free writing prospectuses, you should rely on the prospectus supplement and/or the related free writing prospectuses. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement, together with the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” We have not authorized any other person to provide you with different or additional information other than that contained in or incorporated by reference into this prospectus or any applicable prospectus supplement. We will not take any responsibility, and can make no assurance as to the reliability of, any other information that others may give you. We will not make an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus and the applicable prospectus supplement to this prospectus is accurate as of the date on its respective cover, and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. This prospectus incorporates by reference market data and certain industry data and forecasts that were obtained from market research databases, consultant surveys commissioned by us, publicly available information, reports of governmental agencies and industry publications and surveys. Industry surveys, publications, consultant surveys commissioned by us at and forecasts generally state that the following address information contained therein has been obtained from sources believed to be reliable. We have relied on certain data from third-party sources, including internal surveys, industry forecasts and telephone number: Synthetic Biologicsmarket research, which we believe to be reliable based on our management’s knowledge of the industry. Statements as to our market position are based on the most currently available data. While we are not aware of any misstatements regarding the industry data presented in this prospectus, our estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” in this prospectus and in the relevant prospectus supplement, and under similar headings in the other documents that are incorporated herein or therein by reference. Certain figures included in this prospectus have been subject to rounding adjustments. Accordingly, figures shown as totals in certain tables may not be an arithmetic aggregation of the figures that precede them. As used herein, and unless the context suggests otherwise, the terms “Evogene,” “we,” “us,” “our,” “our company” and “the company” refer to Evogene Ltd. and its consolidated subsidiaries, consisting of AgPlenus Ltd., Biomica Ltd., Canonic Ltd., Casterra Ag Ltd., Evogene Inc., 0000 Xxxxxxx Xxxxxx XxxxxLavie Bio Ltd. and their consolidated subsidiaries. References to “dollar” and “$” are to U.S. dollars, Xxxthe lawful currency of the United States, and references to “NIS” are to New Israeli Shekels, the lawful currency of the State of Israel. 000References to our “ordinary shares” or “shares” refer to our ordinary shares, Xxxxxxxxxpar value NIS 0.02 per share. References to our “2019 annual report” refer to our Annual Report on Form 20-F for the year ended December 31, Xxxxxxxx 000002019, which we filed with the SEC on April 27, 2020. Our telephone number is (000) 000-0000Unless otherwise indicated, we have translated NIS amounts into U.S. dollars at an exchange rate of NIS 3.456 to $1.00, the representative exchange rate reported by the Bank of Israel on December 31, 2019.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC Commission allows us to “incorporate by reference” the information we file with it the Commission, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusdocuments. The information incorporated we incorporate by reference is considered to be an important part of this prospectus, and later certain information that we will later file with the SEC Commission will automatically update and supersede this information. We incorporate by reference the documents listed below and as well as any future filings made we make with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Commission pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding, unless otherwise provided therein or herein, documents not deemed “filed” with the Commission and information furnished pursuant to Item 2.02 and Item 7.01 on any Current Report on Form 8-K or certain exhibits furnished pursuant to Item 9.01 of Form 8-K) after (i) the date of the initial registration statement and prior to the effectiveness of the this registration statement, and (ii) any filings made after the date of this prospectus and before the completion of the offerings until we sell all of the securities included under this prospectus. The following documents filed with the Commission are incorporated by reference in this prospectus. · Our annual report : • our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 filed with the SEC on February 22, 2018 (File No. 001-12584)2018; · Our current reports • our Current Reports on Form 8-K (File No. 001-12584) filed with the SEC Commission on January 84, 20182019, January 10, 2019, February 5, 2019 and March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 2019 (File No. 001-12584other than Items 2.02 and 9.01); and · The • the description of our common stock set forth included in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 A12B (File No. 000001-12584)33357) filed with the Commission on March 9, 2007, including any amendment or reports filed for the purpose of updating such description. You Copies of these filings are available at no cost on our website, xxx.xxxxxxxx.xxx. In addition, you may obtain, free of charge, request a copy of these filings and any of these documents (other than amendments thereto at no cost, by writing or telephoning us. Those copies will not include exhibits to these those documents unless the exhibits are specifically incorporated by reference into these in the documents or referred unless you specifically request them. You may also request copies of any exhibits to the registration statement at no cost. Please direct your request to: You should rely only on the information in this prospectus) , any prospectus supplement, any applicable free writing prospectus and the documents that are incorporated by reference. We have not authorized anyone else to provide you with different information. We are not offering these securities in any state where the offering is prohibited by law. You should not assume that the information in this prospectus, any prospectus supplement, any applicable free writing prospectus or calling us at any incorporated document is accurate as of any date other than the following address and telephone number: Synthetic Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000date of the document.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it into this prospectus supplement, which means that we can disclose important information to you by referring you to those documents instead of having to repeat another document filed separately with the information in this prospectusSEC. The information SEC file number for the documents incorporated by reference in this prospectus supplement is considered to be part of Commission File No. 001-35994. The documents incorporated by reference into this prospectus, and later prospectus supplement contain important information that we file you should read about us. The following documents are incorporated by reference into this prospectus supplement: · Our Annual Report on Form 10-K for the year ended December 31, 2019 (Commission File No. 001-35994) filed with the SEC will automatically update on March 30, 2020; · Our Quarterly Report on Form 10-Q for the quarter ended March 31, 2020 (Commission File No. 001-35994) filed with the SEC on May 15, 2020; · Our Current Reports on Form 8-K (Commission File No. 001-35994) filed with the SEC onJanuary 3, 2020, January 21, 2020, February 5, 2020, February 21, 2020, February 27, 2020, March 2, 2020, March 3, 2020, March 5, 2020, March 11, 2020, March 13, 2020, March 17, 2020, March 23, 2020, March 23, 2020, and supersede this informationApril 10, 2020, April 23, 2020, April 28, 2020, April 29, 2020, May 14, 2020, May 29, 2020, June 1, 2020, June 8, 2020; June 22, 2020; and July 27, 2020; · Our Definitive Proxy Statement on Schedule 14A filed with the SEC on July 27, 2020; · The description of our common stock set forth in our registration statement onForm 8-A filed with the SEC on July 8, 2013 (Commission File No. 001-35994); and · The description of our common stock purchase rights set forth in our registration statement on Form 8-A filed with the SEC onMarch 12, 2018, Form 8-A/A (Amendment No. 1) filed on March 13, 2019, Form 8-A/A (Amendment No. 2) filed with the SEC onMarch 13, 2020 (Commission File No. 001-35994). We also incorporate by reference the into this prospectus supplement all documents listed below (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and any future filings made exhibits filed on such form that are related to such items) that are filed by us with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus and before supplement but prior to the completion termination of the offerings of the securities included in this prospectusoffering. · Our annual report These documents include periodic reports, such as Annual Reports on Form 10-K for the fiscal year ended December 31K, 2017 filed with the SEC Quarterly Reports on February 22, 2018 (File No. 001Form 10-12584); · Our current reports Q and Current Reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8K, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive as well as proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584)statements. You may obtain, free of charge, a copy of any of these documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Any statement contained in this prospectus supplement, the accompanying base prospectus or in a document incorporated or deemed to be incorporated by reference in this prospectus supplement and the accompanying base prospectus shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document which also is or is deemed to be incorporated by reference in this prospectus modifies or supersedes that statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We may offer and sell up to $150,000,000 in the aggregate of any combination of the securities identified above from time to time in one or more offerings. This prospectus provides you with a general description of the securities. Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement and any related free writing prospectus before you invest in any of our securities. We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities. Our common stock is listed on the Nasdaq Capital Market under the symbol “HTBX.” On April 20, 2020, the last reported sale price of our common stock on the Nasdaq Capital Market was $0.60 per share. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the other documents that are incorporated by reference into this prospectus. ABOUT THIS PROSPECTU S ii PROSPECTUS SUMMARY 1 RISK FACTORS THAT MAY AFFECT FUTURE RESULTS 5 SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS 6 USE OF PROCEEDS 7 DIVIDEND POLICY 7 DESCRIPTION OF OUR CAPITAL STOCK 8 DESCRIPTION OF WARRANTS 14 DESCRIPTION OF UNITS 16 LEGAL OWNERSHIP OF SECURITIES 17 PLAN OF DISTRIBUTION 20 LEGAL MATTERS 22 EXPERTS 22 WHERE YOU CAN FIND MORE INFORMATION 22 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE 22 This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, (the “SEC”), using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time and in one or more offerings up to a total dollar amount of $150,000,000 of securities as described in this prospectus. Each time that we offer and sell securities, we will provide a prospectus supplement to this prospectus that contains specific information about the securities being offered and sold and the specific terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement, you should rely on the prospectus supplement. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement, together with the additional information described under the heading “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” Neither we, nor any agent, underwriter or dealer has authorized any person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus prepared by or on behalf of us or to which we have referred you. This prospectus, any applicable supplement to this prospectus or any related free writing prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor does this prospectus, any applicable supplement to this prospectus or any related free writing prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the document incorporated by reference, even though this prospectus, any applicable prospectus supplement or any related free writing prospectus is delivered, or securities are sold, on a later date. This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.” Unless otherwise stated or the context otherwise requires, references in this prospectus to “Heat,” the “Company,” “we,” “our” and “us” refer to Heat Biologics, Inc., 0000 Xxxxxxx Xxxxxx Xxxxxa Delaware corporation and its consolidated subsidiaries, Xxxunless otherwise specified. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000When we refer to “you,” we mean the holders of the applicable series of securities.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information we file with it which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectusprospectus supplement. The information incorporated by reference is considered to be part of this prospectusprospectus supplement, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus supplement and before the completion of the offerings of the securities shares of our common stock included in this prospectusprospectus supplement. · Our annual report Annual Report on Form 10-K for the fiscal year ended December 31, 2017 2019 filed with the SEC on February 22onFebruary 20, 2018 2020 (File No. 001-12584); · Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020, June 30, 2020 and September 30, 2020 filed with the SEC onMay 5, 2020, August 6, 2020 and November 10, 2020 and our Quarterly Report on Form 10-Q/A filed with the SEC onNovember 12, 2020; · Our current reports on Form 8-K (File No. 001-12584) filed with the SEC on January 8, 2018, March onJanuary 7, 2018; April 232020, 2018 and May February 7, 20182020, August 5, 2020, September 18, 2020, October 2, 2020, November 12, 2020, November 17, 2020, November 18, 2020, November 24, 2020, December 22, 2020, December 31, 2020 and January 6, 2021; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18onAugust 4, 2017 2020 (File No. 001-12584); and · The description of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June onJune 20, 2007 (File No. 000-12584), as updated by the description of our common stock filed as Exhibit 4.16 to our Annual Report on Form 10-K for the year ended December 31, 2019, including any amendments or reports filed for the purpose of updating such description. You may obtainAny statement contained in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus supplement modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, free except as so modified or superseded, to constitute a part of chargethis prospectus supplement. We will furnish without charge to you, on written or oral request, a copy of any or all of these the documents (other than that are incorporated by reference into this prospectus supplement and the accompanying base prospectus but not delivered with the prospectus supplement, including exhibits to these documents unless the exhibits which are specifically incorporated by reference into these such documents. You should direct any requests for documents or referred to in this prospectus) by writing or calling us at the following address and telephone number: Synthetic Biologics, Inc., Attn: Xxxxxx X. Xxxxxxxxxx, Chief Executive Officer and Chief Financial Officer, 0000 Xxxxxxx Xxxxxx Xxxxx, Xxx. Xxxxx 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is , or telephoning us at (000) 000-0000. You should rely only on information contained in, or incorporated by reference into, this prospectus supplement and the accompanying base prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus supplement or incorporated by reference in this prospectus supplement or the accompanying base prospectus. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation. We may offer and sell up to $200,000,000 in the aggregate of the securities identified above from time to time in one or more offerings. This prospectus provides you with a general description of the securities. Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement before you invest in any of our securities. We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities. Our common stock is listed on the NYSE American LLC under the symbol “SYN.” The last reported sale price of our common stock on the NYSE American LLC on May 3, 2018 was $0.23 per share. We urge prospective purchasers of our common stock to obtain current information about the market prices of our common stock. On February 22, 2018, the date we filed our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, we became subject to the offering limits in General Instruction I.B.6 of Form S-3. As of the date of this prospectus, the aggregate market value of our common stock held by non-affiliates pursuant to General Instruction I.B.6 of Form S-3 is $44,622,699, which is calculated based on 114,799,845 shares of our common stock outstanding held by non-affiliates and a price of $0.3887 per share, the closing price of our common stock on March 16, 2018, which is the highest closing sale price of our common stock on the NYSE American LLC within the prior 60 days of this prospectus. During the prior 12 calendar month period that ends on and includes the date hereof, we have not offered or sold any shares of our common stock pursuant to General Instruction I.B.6 to Form S-3. About this Prospectus i Ratio of Earnings to Fixed Charges and Preferred Stock Dividends 9 This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, (the “SEC”), using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time and in one or more offerings up to a total dollar amount of $200,000,000 of securities as described in this prospectus. We have provided to you in this prospectus a general description of the securities we may offer. Each time that we offer and sell securities under this shelf registration statement, we will, to the extent required by law, provide a prospectus supplement to this prospectus that will contain specific information about the securities being offered and sold and the specific terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or any free writing prospectus, you should rely on the prospectus supplement or free writing prospectus; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus or any prospectus supplement or any related free writing prospectus — the statement in the document having the later date modifies or supersedes the earlier statement. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement, together with the additional information described under the heading “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” Unless otherwise stated or the context otherwise requires, references in this prospectus to “Synthetic” the “Company,” “we,” “our” and “us” refer to Synthetic Biologics, Inc., a Nevada corporation, and its consolidated subsidiaries, unless otherwise specified. When we refer to “you,” we mean the holders of the applicable series of securities.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE. The SEC allows us to “incorporate by reference” the information that we file have filed with it which means that it, meaning we can disclose important information to you by referring you to those documents instead of having to repeat already on file with the information in this prospectusSEC. The information incorporated by reference is considered to be part of this prospectus, prospectus supplement and later the accompanying base prospectus except for any information that is superseded by other information that is included in this prospectus supplement or the accompanying base prospectus. This filing incorporates by reference the following documents, which we file have previously filed with the SEC will automatically update pursuant to the Securities Exchange Act of 1934, as amended, or the Exchange Act (other than Current Reports on Form 8-K, or portions thereof, furnished under Items 2.02 or 7.01 of Form 8-K): · Annual Report on Form 10-K for the year ended June 30, 2019, which was filed with the SEC on August 26, 2019 (Commission File No. 001-35023). · Current Reports on Form 8-K filed with the SEC on October 11, 2019, October 22, 2019, October 28, 2019, October 28, 2019, October 29, 2019, December 13, 2019, January 9, 2020, January 16, 2020, February 6, 2020, February 21, 2020, February 25, 2020, March 9, 2020, March 13, 2020, March 13, 2020, March 18, 2020, March 19, 2020, March 20, 2020, March 30, 2020, April 9, 2020, April 27, 2020, May 14, 2020, June 17, 2020, June 17, 2020, July 9, 2020 and supersede this informationJuly 29, 2020 (Commission File No. 001-35023). · Quarterly Reports on Form 10-Q for the quarters ended September 30, 2019, December 31, 2019 and March 31, 2020, which were filed with the SEC on November 14, 2019, February 14, 2020 and May 15, 2020 (Commission File No. 001-35023). · Definitive Proxy Statement on Schedule 14A filed with the SEC on January 23, 2020, as amended on February 6, 2020 and March 2, 2020 (Commission File No. 001- 35023). · The description of our common stock, par value $0.001 per share, included under the caption “Description of Securities” in the Prospectus forming a part of Amendment No. 2 to the Company’s Registration Statement on Form S-1, filed with the SEC on October 24, 2019 (File No. 333-233504). We also incorporate by reference the into this prospectus supplement all documents listed below (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and any future filings made exhibits filed on such form that are related to such items) that are filed by us with the SEC (other than any portions of any such documents that are not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules) under pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act on or after (i) the date of the initial registration statement and prior to the effectiveness of the registration statement, and (ii) the date of this prospectus supplement and before the completion termination of the offerings of the securities included in this prospectusoffering. · Our annual report These documents include periodic reports, such as Annual Reports on Form 10-K for the fiscal year ended December 31K, 2017 filed with the SEC Quarterly Reports on February 22, 2018 (File No. 001Form 10-12584); · Our current reports Q and Current Reports on Form 8-K (File No. 001-12584) filed with K. We will provide, without charge, to each person, including any beneficial owner, to whom this prospectus supplement and the SEC accompanying base prospectus are delivered, on January 8, 2018, March 7, 2018; April 23, 2018 and May 7, 2018; · Our definitive proxy statement on Schedule 14A filed with the SEC on July 18, 2017 (File No. 001-12584); and · The description written or oral request of our common stock set forth in our registration statement on Form 8-A12B, filed with the SEC on June 20, 2007 (File No. 000-12584). You may obtain, free of chargesuch person, a copy of any or all of these the reports or documents (other than exhibits to these documents unless the exhibits are specifically incorporated by reference into these documents or referred to in this prospectus supplement and the accompanying base prospectus) , but not delivered with this prospectus supplement and the accompanying base prospectus. Any request may be made by writing or calling telephoning us at the following address and or telephone number: Synthetic BiologicsiBio, Inc.Inc. Attention: Investor Relations 000 Xxxxxxx Xxxxxx, Xxxxx 0000 Xxxxxxx Xxxxxx Xxxxx, XxxYou may also access the documents incorporated by reference into this prospectus supplement and the accompanying base prospectus at our website address at xxxxx://xx.xxxxxxx.xxx/sec-filings. 000, Xxxxxxxxx, Xxxxxxxx 00000. Our telephone number is (000) 000-0000The other information and content contained on or linked from our website are not part of this prospectus supplement or the accompanying base prospectus.