The Rent Commencement Date is June 1 ,2024. The Expiration Date is May 31,2034. Riqbt of First offerl Ame.ndment. Effective as of the Effective Date, the first sentence of sectionTTJ of the original Lease, as previously pq.ende{ by Section 6(b) of the...

SECON AMENDMENT LEASE nd 0 NOW, THEREFORE, in consideration of the foregoing agreements, xxx.xx, provisions and conditions herein conta-ined'-, hereby amend the Lease as follows: wlfNEssEfH: A. Reference is made to that certain lease (the "Oriqinal Lease") dated as of Yay.4, ?04.1,between Landlord and...Tenant, for cbrtain dEmEeE-fth-e '?remjgegj located in the building (the."Buildinq) !1own as 000 Xxxxxxx Xxxxxx, Xxxxxxxxx; Connecticut,_as amencl'cd by ttrElcefrain First Amendment date"d as of Augu st lO, Z.OZI (he..'Eirs!-4mqdnqn1", tbgether with the Original Lease, the "rxisTinq Ldaie). Capitalized terms and phrases used and not defi-xxx herein stratt frdve-tfid?e ascribed to them in the- Existing Lggse. For purposes of the Existing Lease and this Second Amendmelt, refelenqes to "the Lease'] or"'this Lease" or wordi of simltai import shall mean and refer to th.e Existing Lease, as amended by this Second nmenOm'ent, unless the context clearly dictates otherwise. B. The Existing -Lease .provides that the Premises contains approximately 164577 rentable gquag feet and'constituting. the 4th, 5th and 6th floors of ihe euiiding'. As further set forth-herein, Tenant desires tdlease certain additional space tocaied oii the first (1st) floor of the Building. C. Xxxxxxxx's Work has been substantially completed and the final remeasurement has been completed by Xxxxx Xxxxxxxx-Xxxxxxx'cts Ltd. and certified to Landlord and Xxxxxx in accorciance with the Lease. Per the final remeasurement, 1i) Jlt"-l"llqble square footage of the. Premises is 163,784 in the aggregate, comprise'd'o'f O 54,35?._renlable g-q.u?r.ej9gt on the sixth (6th) floor, (ii) 54,556 idntaile iquarb feet on the,fifth (Sth) floor, (iii) 54,645-.re1!qQ!e-.squa're Teet oh'the fourth (4th) floor,'and (iv) 2C1 rentable square feet on the first (1't) floilr, gnd (y) the rentable .square footagei <it ttre Expansion space is 53,435 rentable 3quare feet ciir'the third (3d) flobr. D. ln accordance with Section 39.1 of the Lease, Landlord and Tenant are entering into this Second Amendment to (i) confirm. the final ientable square footages of the Premises, the Expansion Space, anci the Building, and (ii) chaniles in the"fiieA Rent and other xxxxx.xx due under the Lease based uifon the ientabld square tootage of the Premises andlhe Building and the increased amount of Landlord's'Contribuiiol, as set forth below, Execution Copy dated as of December , LLC ("Landlord") and the covenants, Landlord and Tenant 1. Recitals. The Recitals set forth above are true and correct and by this referenceTre incorporated herein in itreir entiEit.- 2. Modification of Premises. ^ (a) Effective as of the Effective Date, the definition of "Premises" set forth in Section 2.1 of the Lease, as previously'amended by Section 2(a) of tfre firit -1- t :l 1605472224.4 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. Exhibit 10.3

Amendment, is hereby amended by deleting the first sentence of Section 2.1 of the Lease in its entirety and replacing it with the following: "Landlord hereby leases to Tenant, and Tenant hereby hires from Landlord, the premises hereinafter described (the "Premises"), consisting of approximately 163,784 rentable square feet consisting of the 4th, 5th and 6 th floors, and a portion of the 1 st floor, of a building, associated below grade parking garage, and associated subsurface improvements known as 000 Xxxxxxx Xxxxxx, Xxx Xxxxx, Xxxxxxxxxxx (the "Building"), as such Premises are shown on the plans attached hereto as Exhibit 2.1 (the "Premises Plans"), together with the non-exclusive right to use the common areas for their intended purposes, for the Term hereinafter stated, for the rents hereinafter reserved, and upon and subject to the terms, restrictions and reservations hereinafter provided in this Lease and those matters of record set forth on Exhibit 2.1 (a), all of which Tenant shall conform to (Landlord represents that none of such matters of record prohibit use of the Premises for the Permitted Use)." (b) Effective as of the Effective Date, Exhibit 2.1 to the Lease, as previously amended by Section 2(b) of the First Amendment, is hereby deleted in its entirety and replaced with Exhibit 2.1 attached to this Second Amendment. (c) Effective as of the Effective Date, Exhibit 4.1 to the Lease, as previously amended by Section 2(c) of the First Amendment, is hereby deleted in its entirety and replaced with Exhibit 4.1 attached to this Second Amendment. 3. Modification of Expansion Space Square Footage. (a) Effective as of the Effective Date, the definition of "Expansion Space" set forth in Section 36.1 of the Lease, as previously amended by Section 3 of the First Amendment, is hereby amended by deleting the first two sentences of Section 36.1 in their entirety and replacing them with the following sentence: "Provided that Tenant is not in default (beyond applicable notice or cure period(s)) of its obligations under this Lease at the time Tenant makes such election or at the time that the Expansion Space (as defined below) is added to this Lease, Tenant shall have the one-time right to expand the Premises (the "Expansion Option") to include the third (3rd) floor of the Building consisting of approximately 53,435 rentable square feet (the "Expansion Space"), as such Expansion Space is shown on the plan attached hereto as Exhibit 2.1-1, effective during the first Lease Year by providing prior written notice (the "Expansion Notice") to Landlord at least six (6) months prior to the date (the "Expansion Delivery Date") within the first Lease Year that Tenant seeks to add the Expansion Space to the Premises." (b) Exhibit 2.1-1 showing the Expansion Space is attached hereto. 4. [**] Landlord's Contribution. The parties hereby confirm that, in accordance with Section 4 of the First Amendment, the [**] Letter of Credit was timely delivered to Landlord and the Landlord's Contribution was [**] to $[**] per rentable square foot of the Premises. Accordingly, Xxxxxxxx's Contribution shall be $[**] (the product of (i) $[**] times (ii) [**]). 5. Additional Amendments to Lease. Effective as of the Effective Date, Xxxxxxxx and Xxxxxx hereby agree to further amend the Existing Lease, as follows: - 2 - 1605472224.4

The Rent Commencement Date is June 1 ,2024. The Expiration Date is May 31,2034. Riqbt of First offerl Ame.ndment. Effective as of the Effective Date, the first sentence of sectionTTJ of the original Lease, as previously pq.ende{ by Section 6(b) of the First Ameridment, is liere6y deleted in its entirety and replaced with the following: "ln the ey.en! that during the Term, any leasable space on a floor in the Building..that -is. corttigu-ous to the initial (after tat<ing into account the modification of the Premises set forth in Section 2 of th6 First Amendment) Premises leased hereunder_(gnd, following the exercise of Tenant's expansion lghts pursuant to Article 36, lhg Premi-ses as so expanded) (the "'ROFOSpace") is or is to become available for rental and Lanblord wishes to lease such space to. any person other than the then current occupant(s) thereof (if any), and, in the further event that Tenant is not then in deiault'(6evond ariv applicable g.facg or notice period) of its obligations to Landlor<i uhder this Lease, Landlord. shall, befoie entering into a Lease for all or any portion of 1t1c! 9g-ace-, .make a written offer to l6ase the same to Tenant ('Lindlord's RFO Offer")." 6. Lender Conselt. Landlord represents to Tenant that, as of the Effective Date, Landlord TafiFiaineilTrom the troioei oi its exi-s1ing mortgagb Conseni t,o ttrir Second Amendment. 7: Brgkerase, Eacll of Landlord and Xxxxxx represents that in the negotiation of this Second Amendment it dealt with no real estate'broker or salesman. Each party shall indemnify.and hold harmless the other pJrty trom iny ino ariroJJ"rloamigeiin6 expenses arising out of any inaccuracy oi alleged inaccuracv bt the- above rep.resentation. The_foregoing.indemnity shbll also coier all fees, codts and expenses, including,3t!opey9' fees, -w.hlch the claiming party incurs to def6nd against any sucti claim (wJtich .the indemnifying party shall pay upon demand). The piovisions bt ttris Section 7 shall survive the expiration or earlieriermination of th'e Leasei. _ .8., .Ratification of the Lease. As modified by this Second Amendment, theExistingLffints,agreementi,terms,provisionsanoconoitioni thereof are hereby ratified and confirmed b/Tenant and Landlord in all respects. 9. Counterparts, This Second Amendment may be executed in one or more counterparts (including by fax, pdf or other electrohic means) and each of such counterparts sha.ll, for all purposes, be deemed to be an original, but all such counterparts shall, when taken together, constitute one and the sarie instrument. The delivery of an unexecuted counterpart of this Second Amendment to Tenant shall not be deemed an offer by Landlord..and this Second Amendment shall not be binding on Landlord unless and until Landlord shall deliver to Tenant a fully executed counffiart hereof. [Balance of Page lntentionally Left Blank - Signature Page to Follow] (a) (b) (c) T : t605472224.4 3

A.- lN WTNESS WHEREOF, Landlord and Xxxxxx have executed thls Second Amendment as of the day and year ?irst written above. LANDLORD: 000 XXXXXXX XXXXXX, LLC Wtness: By: HRSE- l, LLC, lts Sole Member xx xxx Authorized natory TENANT: XXXXXXX XXXXXXXXX, INC. By: Title: Xxxx xXx Treasurer ViryiniaBarbati ie n By: Sfrp Guarantor hereby confirms its otligation as Guarantor as set forth in the Guaranty dated as of May 4,2021 in connection with the Lease and specifically confirms tfrit suclr Guaranty extends to and applies with respect to the Lease, as amended by tnis SeconO Amendment: Wtness: GUARANTOR: ARVINAS, INC. BY: Name: Title: c.{'a or C; +,,.. 'l^u : : t605472224.4 "\{* 4

srArE@tg couNry ee MiddlesFff' otlt1tt,$.'xxxx,ryv me, personally appeared 101 GOLLEGE STREET, acknowledged the same LLG, and his/her free act Concord s to be free act and and deed as such STATE OF City/Town 0 OLLEGE thereof. before Expires: thereof. of an of whor lN WTNESS WHEREOF, I hereunto set my hand and offlclalseal. PAdT ff\, 1tllllll17, f1 Notary Public My Commisslon " ("_r r*) * //1ilil\ $"- \-\t^-^ ) ss. .e>\- nd officialseal. COUNTY OF On this the. day er sea to the free act and deed act and deed as such lN WTNESS WHEREOF, I hereunto Notary Publlc My Commisslon Expkes: XXXXX XXXXXXX Notary Publlo, Stale of Connedlcut My Gommisslon ExPhes 06/30/2028 I XXXXX XXXXXXX Notary PnUlq Shto of ConnecUqfl t605472224,4 -5-