REGISTRATION RIGHTS AGREEMENT

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EXHIBIT 4.1

This Registration Rights Agreement, dated as of March 22, 2001 (this "Rights Agreement"), is made by and between SuperGen, Inc. (the "Corporation") and The Xxxxxxxxx Group ("Xxxxxxxxx").

WHEREAS, the Corporation and Xxxxxxxxx have entered into an Agreement, dated as of March 22, 2001 (the "Agreement") that provides for the issuance of warrants (the "Warrants") to Xxxxxxxxx from the Corporation to purchase shares of the Corporation's common stock (the "Common Stock"); and

WHEREAS, the Corporation and Xxxxxxxxx xxxx it to be in their respective best interests to set forth the rights of Xxxxxxxxx in connection with public offerings and sales of the Common Stock issuable upon exercise of the Warrants.

NOW, THEREFORE, in consideration of the premises and mutual covenants and obligations hereinafter set forth, the Corporation and Xxxxxxxxx hereby agree as follows:

Section 1. Definitions. As used in this Agreement, the following terms shall have the following meanings:

(a): "Closing Date" means the date of closing of any sale of shares of Common Stock issuable upon exercise of the Warrants pursuant to the Agreement.
(b): "Commission" means the Securities and Exchange Commission or any other Federal agency at the time administering the Securities Act.
(c): "Demand for Registration" means a written notice signed by the holders of more than 50% of the then outstanding Registrable Shares delivered to the Corporation requesting registration of the Registrable Shares.
(d): "Exchange Act" means the Securities Exchange Act of 1934 or any successor Federal statute, and the rules and regulations of the Commission promulgated thereunder, all as the same shall be in effect from time to time.
(e): "Other Shares" means at any time those shares of Common Stock held by any person (or issuable upon exercise or conversion of any security held by any person) that do not constitute Primary Shares or Registrable Shares.
(f): "Primary Shares" means at any time the authorized but unissued shares of Common Stock and shares of Common Stock held by the Corporation in its treasury.
(g): "Registrable Shares" means Restricted Shares that constitute Common Stock issuable upon exercise of the Warrants; provided, however, that Restricted Shares that constitute Common Stock shall only be treated as Registrable Securities if and so long as they have not been (i) sold to or through a broker or dealer or underwriter in a registered public distribution or a registered public securities transaction, or (ii) sold or are available for sale in a single transaction exempt from the registration and prospectus delivery requirements of the Securities Act so that all transfer restrictions and restrictive legends with respect thereto are removed upon the consummation of such sale pursuant to Rule 144.
(h): "Restricted Shares" means shares of Common Stock issued upon the exercise of the Warrants pursuant to the Agreement and held by the Securityholders. As to any particular Restricted Shares, once issued, such Restricted Shares shall cease to be Restricted Shares when (i) they have been registered under the Securities Act, the registration statement in connection therewith has been declared effective and they have been disposed of pursuant to such effective registration statement, or (ii) they shall have ceased to be outstanding.

(i): "Securities Act" means the Securities Act of 1933 or any successor Federal statute, and the rules and regulations of the Commission thereunder, all as the same shall be in effect from time to time.
(j): "Securityholders" means Xxxxxxxxx as the purchaser of the Restricted Shares and includes any successor to, or assignee or transferee of, Xxxxxxxxx who shall agree in writing to be treated as a Securityholder hereunder and to be bound by the terms and comply with all applicable provisions hereof.

Section 2. Demand Registration. Provided that the Securityholders deliver a Demand for Registration within four months from the date of this Agreement, the Corporation agrees to file a registration statement covering all of the Registrable Shares then outstanding and to use its reasonable best efforts to cause that registration statement to become effective under the Securities Act by no later than October 7, 2001. The Corporation agrees to promptly file, and cause to become effective under the Securities Act within 90 days of such filing, additional registration statements following receipt of Demand for Registration delivered more than one year from the date of this Agreement covering Registrable Shares that were not previously registered. The Corporation shall not be obligated to effect any registration under the Securities Act except in accordance with the following provisions:

(a): the Corporation shall not be obligated to file more than one registration statement pursuant to this Section 2 with respect to any of the Registrable Shares that were outstanding at the time of effectiveness of a registration statement covering any of the Registrable Shares where those outstanding shares could have been included in the registration statement that went effective;
(b): with respect to any registration pursuant to this Section 2, the Corporation shall give notice of such registration to the Securityholders hereunder and to the holders of all Other Shares which are entitled to registration rights and the Corporation may include in such registration any Primary Shares or Other Shares;
(c): if the method of disposition requested by the holders, pursuant to this Section 2, is an underwritten public offering, the majority of the holders of Registrable Shares shall have the right to designate the managing underwriter of such offering, which underwriter shall be reasonably acceptable to the Corporation; and
(d): at any time before the registration statement covering Registrable Shares becomes effective, the holders of a majority of such shares may request the Corporation to withdraw or not to file the registration statement. In that event, if such request of withdrawal shall not have been caused by, or made in response to, the material adverse effect of an event on the business, properties, condition, financial or otherwise, or operations of the Corporation, the Company shall have no further obligations with respect to the registration of Registrable Shares under this Section 2 unless the holders shall pay to the Corporation the expenses incurred by the Corporation through the date of such request.

Section 3. Piggyback Registration. If the Corporation proposes for any reason to register Primary Shares or Other Shares under the Securities Act (other than on Form S-4 or Form S-8 promulgated under the Securities Act or any successor forms thereto) by filing a registration statement with the Commission at any time, it shall promptly give written notice to the Securityholders of its intention to so register such Primary Shares or Other Shares and, upon the written request, delivered to the Corporation within 30 days after delivery of any such notice by the Corporation, of any Securityholder to include in such registration Registrable Shares (which request shall specify the number of Registrable Shares proposed to be included in such registration), the Corporation shall use its reasonable best efforts to cause all such Registrable Shares of Securityholders delivering such notice to be included in such registration on the same terms and conditions as the securities otherwise being sold

in such registration; provided, however, that if the managing underwriter advises the Corporation that the inclusion of all Registrable Shares requested to be included in such registration would interfere with the successful marketing (including pricing) of the Primary Shares or Other Shares proposed to be registered by the Corporation, then the number of Primary Shares, Registrable Shares and Other Shares proposed to be included in such registration shall be included in the following order:

(a)

if the Corporation proposes to register Primary Shares:

(i): first, the Primary Shares; and
(ii): second, the Registrable Shares and Other Shares requested to be included in such registration (or, if necessary, such Registrable Shares and Other Shares pro rata among the holders thereof based upon the number of Registrable Shares and Other Shares requested to be registered by each such holder); or

(b)

if the Corporation proposes to register Other Shares pursuant to a request for registration by the holders of such Other Shares:

(i): first, the Other Shares held by the parties demanding such registration;
(ii): second, the Registrable Shares and Other Shares (other than shares registered pursuant to Section 3(b)(i) hereof) requested to be registered by the holders hereof (or, if necessary, pro rata among the holders thereof based on the number of Registrable Shares and Other Shares requested to be registered by such holders); and

All proposing to distribute their securities through such underwriting under this Section 2 shall (together with the Company and the other holders distributing their securities through such underwriting) enter into an underwriting agreement in customary form with the managing underwriter selected for such underwriting by the Company. Notwithstanding any other provision of this Agreement, if the managing underwriter determines that marketing factors require a limitation of the number of shares to be underwritten, the managing underwriter and the Company may reduce the Registrable Shares to included in such registration to the extent the underwriters deem necessary.

Section 4. Preparation and Filing. If and whenever the Corporation is under an obligation pursuant to the provisions of this Agreement to effect the registration of any Registrable Shares, the Corporation shall, as expeditiously as practicable:

(a): cause a registration statement that registers such Registrable Shares to become and remain effective until the earlier of the date that is five years after the Closing Date with respect to the Registrable Shares that are being registered or until all of such Registrable Shares have been disposed of;
(b): prepare and file with the Commission such amendments and supplements to such registration statement and the prospectus used in connection therewith as may be necessary to keep such registration statement effective until the earlier of the date that is five years after the Closing Date with respect to the Registrable Shares that are being registered or until all of such Registrable Shares have been disposed of and to comply with the provisions of the Securities Act with respect to the sale or other disposition of such Registrable Shares;
(c): register or qualify such Registrable Shares under such other securities or blue sky laws of such jurisdictions as the Securityholders reasonably request and do any and all other acts and things which may be reasonably necessary or advisable to enable the Securityholders to consummate the disposition in such jurisdictions of the Registrable Shares owned by the Securityholders; provided, however, that the Corporation will not be required to qualify generally to do business, subject itself to general taxation or consent to general service of process in any jurisdiction where it would not otherwise be required to do so but for this paragraph (c) or to

provide any material undertaking or make any changes in its By-laws or Certificate of Incorporation which the Board of Directors determines to be contrary to the best interests of the Corporation;

(d): upon written request furnish to the Securityholders holding such Registrable Shares such number of copies of a summary prospectus, if any, or other prospectus, including a preliminary prospectus, in conformity with the requirements of the Securities Act, and such other documents as such Securityholders may reasonably request in order to facilitate the public sale or other disposition of such Registrable Shares;
(e): use commercially reasonable efforts to cause such Registrable Shares to be registered with or approved by such other governmental agencies or authorities as may be necessary by virtue of the business and operations of the Corporation to enable the Securityholders holding such Registrable Shares to consummate the disposition of such Registrable Shares;
(f): notify the Securityholders holding such Registrable Shares on a timely basis at any time when a prospectus relating to such Registrable Shares is required to be delivered under the Securities Act within the appropriate period mentioned in subparagraph (a) of this Section 4, of the happening of any event as a result of which the prospectus included in such registration statement, as then in effect, includes an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances then existing and, at the request of the Securityholders, prepare and furnish to such Securityholders a reasonable number of copies of a supplement to or an amendment of such prospectus as may be necessary so that, as thereafter delivered to the offerees of such shares, such prospectus shall not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances then existing;
(g): subject to the execution of confidentiality agreements in form and substance satisfactory to the Corporation, make available upon reasonable notice and during normal business hours, for inspection by the Securityholders holding such Registrable Shares, any underwriter participating in any disposition pursuant to such registration statement and any attorney, accountant or other agent retained by the Securityholders or underwriter (collectively, the "Inspectors"), all pertinent financial and other records, pertinent corporate documents and properties of the Corporation (collectively, the "Records"), as shall be reasonably necessary to enable them to exercise their due diligence responsibility, and cause the Corporation's officers, directors and employees to supply all information (together with the Records, the "Information") reasonably requested by any such Inspector in connection with such registration statement. Any of the Information which the Corporation determines in good faith to be confidential, and of which determination the Inspectors are so notified, shall not be disclosed by the Inspectors unless (i) the disclosure of such Information is necessary to avoid or correct a misstatement or omission in the registration statement, (ii) the release of such Information is ordered pursuant to a subpoena or other order from a court of competent jurisdiction or (iii) such Information has been made generally available to the public; the Securityholders agree that they will, upon learning that disclosure of such Information is sought in a court of competent jurisdiction, give notice to the Corporation and allow the Corporation, at the Corporation's expense, to undertake appropriate action to prevent disclosure of the Information deemed confidential;
(h): use its reasonable best efforts to obtain from its independent certified public accountants "cold comfort" letters in customary form and at customary times and covering matters of the type customarily covered by cold comfort letters;

(i): use icommercially reasonable efforts to obtain from its counsel an opinion or opinions in customary form;
(j): provide a transfer agent and registrar (which may be the same entity) for such Registrable Shares;
(k): issue to any underwriter to which the Securityholders holding such Registrable Shares may sell shares in such offering certificates evidencing such Registrable Shares;
(l): list such Registrable Shares on any national securities exchange on which any shares of the Common Stock are listed or, if the Common Stock is not listed on a national securities exchange, use commercially reasonable efforts to qualify such Registrable Shares for inclusion on the automated quotation system of the National Association of Securities Dealers, Inc. (the "NASD"), or such other national securities exchange as the holders of a majority of such Registrable Shares shall reasonably request;
(m): use commercially reasonable efforts to take all other steps necessary to effect the registration of such Registrable Shares contemplated hereby.
(n): Each holder of the Registrable Shares, upon receipt of any notice from the Corporation of any event of the kind described in Section 4(f) hereof, shall forthwith discontinue disposition of the Registrable Shares pursuant to the registration statement covering such Registrable Shares until such holder's receipt of the copies of the supplemented or amended prospectus contemplated by Section 4(f) hereof, and, if so directed by the Corporation, such holder shall deliver to the Corporation all copies, other than permanent file copies then in such holder's possession, of the prospectus covering such Registrable Shares at the time of receipt of such notice.

Section 5. Expenses. All expenses (other than underwriting discounts and commissions relating to the Registrable Shares, as provided in the last sentence of this Section 5) incurred by the Corporation in complying with Section 4, including, without limitation, all registration and filing fees (including all expenses incident to filing with the NASD), fees and expenses of complying with securities and blue sky laws, printing expenses, and fees and expenses of the Corporation's counsel and accountants, shall be paid by the Corporation; provided, however, that all underwriting discounts and selling commissions applicable to the Registrable Shares and Other Shares shall be borne by the holders selling such Registrable Shares and Other Shares, in proportion to the number of Registrable Shares and Other Shares sold by each such holder.

Section 6. Indemnification.

(a): In connection with any registration of any Registrable Shares under the Securities Act pursuant to this Agreement, the Corporation shall indemnify and hold harmless the holders of Registrable Shares, each underwriter, broker or any other person acting on behalf of the holders of Registrable Shares and each other person, if any, who controls any of the foregoing persons within the meaning of the Securities Act against any losses, claims, damages or liabilities, joint or several (or actions in respect thereof), to which any of the foregoing persons may become subject under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon (i) an untrue statement or allegedly untrue statement of a material fact contained in the registration statement under which such Registrable Shares were registered under the Securities Act, any preliminary prospectus or final prospectus contained therein or otherwise filed with the Commission, any amendment or supplement thereto or any document incident to registration or qualification of any Registrable Shares, or (ii) the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading or, with respect to any prospectus, necessary to make

the statements therein in light of the circumstances under which they were made not misleading, or any violation by the Corporation of the Securities Act or state securities or blue sky laws applicable to the Corporation and relating to action or inaction required of the Corporation in connection with such registration or qualification under such state securities or blue sky laws. The Corporation shall reimburse the holders of Registrable Shares, any underwriter or broker or such other person acting on behalf of the holders of Registrable Shares and each controlling person of such underwriters, brokers or other persons for any legal or other expenses reasonably incurred by any of them in connection with investigating or defending any such loss, claim, damage, liability or action; provided, however, that the Corporation shall not be liable in any such case to the extent that any such loss, claim, damage, liability or action (including any legal or other expenses incurred) arises out of or is based upon an untrue statement or allegedly untrue statement or omission or alleged omission made in said registration statement, preliminary prospectus, final prospectus, amendment, supplement or document incident to registration or qualification of any Registrable Shares in reliance upon and in conformity with written information furnished to the Corporation through an instrument duly executed by the holders of Registrable Shares or their counsel or underwriter specifically for use in the preparation thereof; provided further, however, that the foregoing indemnity agreement is subject to the condition that, insofar as it relates to any untrue statement, allegedly untrue statement, omission or alleged omission made in any preliminary prospectus but eliminated or remedied in the final prospectus (filed pursuant to Rule 424 of the Securities Act), such indemnity agreement shall not inure to the benefit of any Securityholder, underwriter, broker or other person acting on behalf of holders of the Restricted Shares from whom the person asserting any loss, claim, damage, liability or expense purchased the Restricted Shares which are the subject thereof, if a copy of such final prospectus had been made available to such selling person and such Securityholder, underwriter, broker or other person acting on his behalf and such final prospectus was not delivered to the purchaser with or prior to the written confirmation of the sale of such Registrable Shares to such purchaser.

(b): In connection with any registration of Registrable Shares under the Securities Act pursuant to this Agreement, each holder of Registrable Shares shall severally and jointly indemnify and hold harmless (in the same manner and to the same extent as set forth in the preceding paragraph of this Section 6) the Corporation, each director of the Corporation, each officer of the Corporation who shall sign such registration statement, each underwriter, broker or other person acting on behalf of the holders of Registrable Shares and each person who controls any of the foregoing persons within the meaning of the Securities Act with respect to any statement or omission from such registration statement, any preliminary prospectus or final prospectus contained therein or otherwise filed with the Commission, any amendment or supplement thereto or any document incident to registration or qualification of any Registrable Shares, if such statement or omission was made in reliance upon and in conformity with written information furnished by the holders of Registrable Shares to the Corporation or such underwriter specifically for use in connection with the preparation of such registration statement, preliminary prospectus, final prospectus, amendment, supplement or document; provided, however, that the maximum amount of liability in respect of such indemnification shall be limited, in the case of each seller of Registrable Shares, to an amount equal to the net proceeds actually received by such Seller from the sale of Registrable Shares effected pursuant to such registration.
(c): Promptly after receipt by an indemnified party of notice of the commencement of any action involving a claim referred to in the preceding paragraphs of this Section 6, such indemnified party will, if a claim in respect thereof is made against an indemnifying party, give written notice to the latter of the commencement of such action. In case any such action is brought

against an indemnified party, the indemnifying party will be entitled to participate in and to assume the defense thereof, jointly with any other indemnifying party similarly notified to the extent that it may wish, with counsel reasonably satisfactory to such indemnified party, and after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be responsible for any legal or other expenses subsequently incurred by the indemnified party in connection with the defense thereof; provided, however, that if any indemnified party shall have reasonably concluded, based upon the advice of counsel, that there may be one or more legal or equitable defenses available to such indemnified party which are additional to or conflict with those available to the indemnifying party, or that such claim or litigation involves or could have an effect upon matters beyond the scope of the indemnity agreement provided in this Section 6, the indemnifying party shall not have the right to assume the defense of such action on behalf of such indemnified party and such indemnifying party shall reimburse such indemnified party and any person controlling such indemnified party for that portion of the reasonable fees and expenses of any one counsel retained by the indemnified party which is reasonably related to the matters covered by the indemnity agreement provided in this Section 6.

Section 7. Information by Holder. The Securityholders shall furnish to the Corporation such written information regarding the Securityholders and the distribution proposed by the Securityholders as the Corporation may reasonably request in writing and as shall be reasonably required in connection with any registration, qualification or compliance referred to in this Agreement.

Section 8. Successors and Assigns. This Agreement shall bind and inure to the benefit of the Corporation and the Securityholders and, subject to Section 9, the respective successors and assigns of the Corporation and the Securityholders.

Section 9. Assignment. Each Securityholder may assign its rights hereunder to any purchaser or transferee of Registrable Shares to the extent permissable under federal and state securities laws; provided, however, that such purchaser or transferee shall, as a condition to the effectiveness of such assignment, be required to execute a counterpart to this Agreement agreeing to be treated as a Securityholder whereupon such purchaser or transferee shall have the benefits of, and shall be subject to the restrictions contained in, this Agreement as if such purchaser or transferee was originally included in the definition of an Securityholder herein and had originally been a party hereto.

Section 10. Entire Agreement. This Agreement contains the entire agreement among the Corporation and the Securityholders with respect to the subject matter hereof and supersedes all prior and contemporaneous arrangements or understandings with respect thereto.

Section 11. Notices. All notices, requests, consents and other communications hereunder to any party shall be deemed to be sufficient if contained in a written instrument delivered in person or sent by facsimile, nationally-recognized overnight courier or first class registered or certified mail, return receipt requested, postage prepaid, addressed to such party at the address set forth below or such other address as may hereafter be designated in writing by such party to the other parties:

(i): if to the Corporation, to:

Xx. Xxxxxx Xxxxxxxxx
Chairman and Chief Executive Officer
SuperGen, Inc.
0000 Xxxxxx Xxxxxxxxx, Xxxxx 000
Xxxxxx, Xxxxxxxxxx 00000
Facsimile:

(ii): if to the Securityholders, to each such Securityholder at his name and address as set forth in the records of the Company.

All such notices, requests, consents and other communications shall be deemed to have been delivered (a) in the case of personal delivery or delivery by telecopy, on the date of such delivery, (b) in the case of dispatch by nationally-recognized overnight courier, on the next business day following such dispatch and (c) in the case of mailing, on the third business day after the posting thereof.

Section 12. Modifications; Amendments; Waivers. The terms and provisions of this Agreement may not be modified or amended, nor may any provision be waived, except pursuant to a writing signed by the Corporation and the holders of at least a majority of the Registrable Shares then outstanding; provided, however, that any amendment to or modification of this Agreement which would have a disproportionate adverse affect on the rights of any Securityholder shall require the written consent of such Securityholder.

Section 13. Counterparts; Facsimile Signatures. This Agreement may be executed in any number of counterparts, and each such counterpart hereof shall be deemed to be an original instrument, but all such counterparts together shall constitute but one agreement.

Section 14. Headings. The headings of the various sections of this Agreement have been inserted for convenience of reference only and shall not be deemed to be a part of this Agreement.

Section 15. Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of California applicable to contracts made and to be performed wholly therein.

IN WITNESS WHEREOF, the parties hereto have executed this Registration Rights Agreement on the date first written above.

		SUPERGEN, INC.
		By:	/s/ XXXXXX XXXXXXXXX Name: Xxxxxx Xxxxxxxxx Title: President/CEO

		THE XXXXXXXXX GROUP
		By:	/s/ XXXXXX X. XXXXXXXXX Name: Xxxxxx X. Xxxxxxxxx Title: President

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