Exhibit 10.5



AKOUOS, INC.   2016 STOCK PLAN: SUMMARY OF STOCK PURCHASE The Purchaser is acquiring shares   of the Common Stock of Akouos, Inc. on the following terms: Name of   Purchaser: Total Number of Purchased Shares: Purchase Price per Share: Date   of Purchase: Vesting Commencement Date: Vesting Schedule: By signing below,   the Purchaser and the Company agree that the acquisition of the Purchased   Shares is governed by the terms and conditions of the 2016 Stock Plan and the   Stock Purchase Agreement. Both of these documents are attached to, and made a   part of, this Summary of Stock Purchase. The Purchaser agrees to accept by   email all documents relating to the Company, the Plan or this purchase and   all other documents that the Company is required to deliver to its security holders   (including, without limitation, disclosures that may be required by the   Securities and Exchange Commission). The Purchaser also agrees that the   Company may deliver these documents by posting them on a website maintained   by the Company or by a third party under contract with the Company. If the   Company posts these documents on a website, it shall notify the Purchaser by   email of their availability. The Purchaser acknowledges that he or she may   incur costs in connection with electronic delivery, including the cost of   accessing the internet and printing fees, and that an interruption of   internet access may interfere with his or her ability to access the   documents. This consent shall remain in effect until the Purchaser gives the   Company written notice that it should deliver paper documents. PURCHASER:   AKOUOS, INC. By: Address for Mailing Stock Certificate: Title:   GDSVF&H\3433550.1 Exhibit 10.5 


    




 










AKOUOS, INC.   2016 STOCK PLAN: STOCK PURCHASE AGREEMENT SECTION 1.ACQUISITION OF SHARES.   (a) Transfer. On the terms and conditions set forth in the Summary of Stock   Purchase and this Agreement, the Company agrees to transfer to the Purchaser   the number of Shares set forth in the Summary of Stock Purchase. The transfer   shall occur at the offices of the Company on the date of purchase set forth   in the Summary of Stock Purchase or at such other place and time as the   parties may agree. (b) Consideration. The Purchaser agrees to pay the   Purchase Price set forth in the Summary of Stock Purchase for each Purchased   Share. The Purchase Price is agreed to be not less than 100% of the Fair   Market Value of the Purchased Shares. Payment shall be made in cash or cash   equivalents on the date of purchase set forth in the Summary of Stock   Purchase. (c)Stock Plan and Defined Terms. The transfer of the Purchased   Shares is subject to the Plan, a copy of which the Purchaser acknowledges   having received. The provisions of the Plan are incorporated into this   Agreement by this reference. Except as otherwise defined in this Agreement   (including without limitation Section 11 hereof), capitalized terms shall   have the meaning ascribed to such terms in the Plan. SECTION 2. RIGHT OF   REPURCHASE. (a) Scope of Repurchase Right.Until they vest in accordance with   the Summary of Stock Purchase and Subsection (b) below, the Purchased Shares   acquired under this Agreement shall be Restricted Shares and shall be subject   to the Company’s Right of Repurchase. The Company, however, may decline to   exercise its Right of Repurchase or may exercise its Right of Repurchase only   with respect to a portion of the Restricted Shares. The Company may exercise   its Right of Repurchase only during the Repurchase Period following the   termination of the Purchaser’s Service, but the Right of Repurchase may be exercised   automatically under Subsection (d) below. If the Right of Repurchase is   exercised, the Company shall pay the Purchaser an amount equal to the lower   of (i) the Purchase Price of each Restricted Share being repurchased or (ii)   the Fair Market Value of such Restricted Share at the time the Right of   Repurchase is exercised. (b) Lapse of Repurchase Right. The Right of   Repurchase shall lapse with respect to the Restricted Shares in accordance   with the vesting schedule set forth in the Summary of Stock Purchase.   (c)Escrow.Upon issuance, the certificate(s) for Restricted Shares shall be   deposited in escrow with the Company to be held in accordance with the   provisions of this Agreement. Any additional or exchanged securities or other   property described in Subsection (f) below shall immediately be delivered to   the Company to be held in escrow. All ordinary cash GDSVF&H\3433550.1 


    




 










dividends on   Restricted Shares (or on other securities held in escrow) shall be paid   directly to the Purchaser and shall not be held in escrow. Restricted Shares,   together with any other assets held in escrow under this Agreement, shall be   (i) surrendered to the Company for repurchase upon exercise of the Right of   Repurchase or the Right of First Refusal or (ii) released to the Purchaser   upon his or her request to the extent that the Shares have ceased to be   Restricted Shares (but not more frequently than once every six months). In   any event, all Purchased Shares that have ceased to be Restricted Shares,   together with any other vested assets held in escrow under this Agreement,   shall be released within 90 days after the earlier of (i) the termination of   the Purchaser’s Service or (ii) the lapse of the Right of First Refusal.   (d)Exercise of Repurchase Right. The Company shall be deemed to have   exercised its Right of Repurchase automatically for all Restricted Shares as   of the commencement of the Repurchase Period, unless the Company during the   Repurchase Period notifies the holder of the Restricted Shares pursuant to Section   9 that it will not exercise its Right of Repurchase for some or all of the   Restricted Shares. The Company shall pay to the holder of the Restricted   Shares the purchase price determined under Subsection (a) above for the   Restricted Shares being repurchased. Payment shall be made in cash or cash   equivalents and/or by canceling indebtedness to the Company incurred by the   Purchaser in the purchase of the Restricted Shares. The certificate(s)   representing the Restricted Shares being repurchased shall be delivered to   the Company. (e) Termination of Rights as Stockholder. If the Right of   Repurchase is exercised in accordance with this Section 2 and the Company   makes available the consideration for the Restricted Shares being   repurchased, then the person from whom the Restricted Shares are repurchased   shall no longer have any rights as a holder of the Restricted Shares (other   than the right to receive payment of such consideration). Such Restricted   Shares shall be deemed to have been repurchased pursuant to this Section 2,   whether or not the certificate(s) for such Restricted Shares have been   delivered to the Company or the consideration for such Restricted Shares has   been accepted. (f) Additional or Exchanged Securities and Property. In the   event of a merger or consolidation of the Company, a sale of all or   substantially all of the Company’s stock or assets, any other corporate   reorganization, the declaration of a stock dividend, the declaration of an   extraordinary dividend payable in a form other than stock, a spin-off, a   stock split, an adjustment in conversion ratio, a recapitalization or a   similar transaction affecting the Company’s outstanding securities, any   securities or other property (including cash or cash equivalents) that are by   reason of such transaction exchanged for, or distributed with respect to, any   Restricted Shares or into which such Restricted Shares thereby become   convertible shall immediately be subject to the Right of Repurchase.   Appropriate adjustments to reflect the exchange or distribution of such   securities or property shall be made to the number and/or class of the   Restricted Shares. Appropriate adjustments shall also be made to the price   per share to be paid upon the exercise of the Right of Repurchase, provided   that the aggregate purchase price payable for the Restricted Shares shall   remain the same. In the event of any transaction described in Section 8(b) of   the Plan or any other corporate reorganization, the Right of Repurchase may   be exercised by the Company’s successor. GDSVF&H\3433550.1 2 


    




 










(g) Transfer of   Restricted Shares. The Purchaser shall not transfer, assign, encumber or   otherwise dispose of any Restricted Shares without the Company’s written   consent, except as provided in the following sentence. The Purchaser may   transfer Restricted Shares to one or more members of the Purchaser’s   Immediate Family or to a trust established by the Purchaser for the benefit   of the Purchaser and/or one or more members of the Purchaser’s Immediate   Family, provided in either case that the Transferee agrees in writing on a   form prescribed by the Company to be bound by all provisions of this   Agreement. If the Purchaser transfers any Restricted Shares, then this   Agreement shall apply to the Transferee to the same extent as to the   Purchaser. (h) Assignment of Repurchase Right. The Board of Directors may   freely assign the Company’s Right of Repurchase, in whole or in part. Any   person who accepts an assignment of the Right of Repurchase from the Company   shall assume all of the Company’s rights and obligations under this Section   2. (i) Part-Time Employment and Leaves of Absence. If the Purchaser commences   working on a part-time basis, then the Company may adjust the vesting   schedule set forth in the Summary of Stock Purchase. If the Purchaser goes on   a leave of absence, then the Company may adjust the vesting schedule set   forth in the Summary of Stock Purchase in accordance with the Company’s leave   of absence policy or the terms of such leave. Except as provided in the   preceding sentence, Service shall be deemed to continue while the Purchaser   is on a bona fide leave of absence, if (i) such leave was approved by the   Company in writing and (ii) continued crediting of Service is expressly   required by the terms of such leave or by applicable law (as determined by   the Company). Service shall be deemed to terminate when such leave ends,   unless the Purchaser immediately returns to active work. SECTION 3. RIGHT OF   FIRST REFUSAL. (a) Right of First Refusal. In the event that the Purchaser   proposes to sell, pledge or otherwise transfer to a third party any Purchased   Shares, or any interest in Purchased Shares, the Company shall have the Right   of First Refusal with respect to all (and not less than all) of such   Purchased Shares. If the Purchaser desires to transfer Purchased Shares, the   Purchaser shall give a written Transfer Notice to the Company describing   fully the proposed transfer, including the number of Purchased Shares   proposed to be transferred, the proposed transfer price, the name and address   of the proposed Transferee and proof satisfactory to the Company that the   proposed sale or transfer will not violate any applicable federal, State or   foreign securities laws. The Transfer Notice shall be signed both by the   Purchaser and by the proposed Transferee and must constitute a binding   commitment of both parties to the transfer of the Purchased Shares. The   Company shall have the right to purchase all, and not less than all, of the   Purchased Shares on the terms of the proposal described in the Transfer   Notice (subject, however, to any change in such terms permitted under   Subsection (b) below) by delivery of a notice of exercise of the Right of   First Refusal within 30 days after the date when the Transfer Notice was   received by the Company. (b) Transfer of Shares. If the Company fails to   exercise its Right of First Refusal within 30 days after receiving the   Transfer Notice, the Purchaser may, not later than 90 days after the Company   received the Transfer Notice, conclude a transfer of the Purchased   GDSVF&H\3433550.1 3 


    




 










Shares subject   to the Transfer Notice on the terms and conditions described in the Transfer   Notice, provided that any such sale is made in compliance with applicable   federal, State and foreign securities laws and not in violation of any other   contractual restrictions to which the Purchaser is bound. Any proposed   transfer on terms and conditions different from those described in the   Transfer Notice, as well as any subsequent proposed transfer by the   Purchaser, shall again be subject to the Right of First Refusal and shall   require compliance with the procedure described in Subsection (a) above. If   the Company exercises its Right of First Refusal, the parties shall   consummate the sale of the Purchased Shares on the terms set forth in the Transfer   Notice within 60 days after the Company received the Transfer Notice (or   within such longer period as may have been specified in the Transfer Notice);   provided, however, that in the event the Transfer Notice provided that   payment for the Purchased Shares was to be made in a form other than cash or   cash equivalents paid at the time of transfer, the Company shall have the   option of paying for the Purchased Shares with cash or cash equivalents equal   to the present value of the consideration described in the Transfer Notice.   (c) Additional or Exchanged Securities and Property. In the event of a merger   or consolidation of the Company, a sale of all or substantially all of the   Company’s stock or assets, any other corporate reorganization, a stock split,   the declaration of a stock dividend, the declaration of an extraordinary   dividend payable in a form other than stock, a spin-off, an adjustment in   conversion ratio, a recapitalization or a similar transaction affecting the   Company’s outstanding securities, any securities or other property (including   cash or cash equivalents) that are by reason of such transaction exchanged   for, or distributed with respect to, any Purchased Shares subject to this   Section 3 shall immediately be subject to the Right of First Refusal.   Appropriate adjustments to reflect the exchange or distribution of such   securities or property shall be made to the number and/or class of the   Purchased Shares subject to this Section 3. (d) Termination of Right of First   Refusal.Any other provision of this Section 3 notwithstanding, in the event   that the Stock is readily tradable on an established securities market when   the Purchaser desires to transfer Purchased Shares, the Company shall have no   Right of First Refusal, and the Purchaser shall have no obligation to comply   with the procedures prescribed by Subsections (a) and (b) above. (e)   Permitted Transfers. This Section 3 shall not apply to (i) a transfer by   beneficiary designation, will or intestate succession or (ii) a transfer to   one or more members of the Purchaser’s Immediate Family or to a trust   established by the Purchaser for the benefit of the Purchaser and/or one or   more members of the Purchaser’s Immediate Family, provided in either case   that the Transferee agrees in writing on a form prescribed by the Company to   be bound by all provisions of this Agreement. If the Purchaser transfers any   Purchased Shares, either under this Subsection (e) or after the Company has   failed to exercise the Right of First Refusal, then this Agreement shall apply   to the Transferee to the same extent as to the Purchaser. (f) Termination of   Rights as Stockholder. If the Company makes available, at the time and place   and in the amount and form provided in this Agreement, the consideration for   the Shares to be purchased in accordance with this Section 3, then after such   time the person from whom such Shares are to be purchased shall no longer   have any rights as a holder of such Shares (other than the right to receive   payment of such consideration in accordance with this GDSVF&H\3433550.1 4   


    




 










Agreement).Such   Shares shall be deemed to have been purchased in accordance with the   applicable provisions hereof, whether or not the certificate(s) therefor have   been delivered as required by this Agreement. (g) Assignment of Right of   First Refusal.The Board of Directors may freely assign the Company’s Right of   First Refusal, in whole or in part. Any person who accepts an assignment of   the Right of First Refusal from the Company shall assume all of the Company’s   rights and obligations under this Section 3. SECTION 4. OTHER RESTRICTIONS ON   TRANSFER. (a) Purchaser Representations. In connection with the issuance and   acquisition of Shares under this Agreement, the Purchaser hereby represents   and warrants to the Company as follows: (i) The Purchaser is acquiring and   will hold the Purchased Shares for investment for his or her account only and   not with a view to, or for resale in connection with, any “distribution”   thereof within the meaning of the Securities Act. (ii) The Purchaser   understands that the Purchased Shares have not been registered under the   Securities Act by reason of a specific exemption therefrom and that the   Purchased Shares must be held indefinitely, unless their sale or other   transfer is subsequently registered under the Securities Act or the Purchaser   obtains an opinion of counsel, in form and substance satisfactory to the   Company and its counsel, that such registration is not required. The   Purchaser further acknowledges and understands that the Company is under no   obligation to register the Purchased Shares. (iii) The Purchaser is aware of   Rule 144 under the Securities Act, which permits limited public resales of   securities acquired in a non-public offering, subject to the satisfaction of   certain conditions. These conditions may include (without limitation) that   certain current public information about the issuer be available, that the   resale occur only after a holding period required by Rule 144 has been   satisfied, that the sale occur through an unsolicited “broker’s transaction,”   and that the amount of securities being sold during any three-month period   not exceed specified limitations. The Purchaser acknowledges and understands   that the conditions for resale set forth in Rule 144 have not been satisfied   as of the Date of Purchase and that the Company is not required to take   action to satisfy any such conditions. (iv) The Purchaser will not sell,   transfer or otherwise dispose of the Purchased Shares in violation of the   Securities Act, the Securities Exchange Act of 1934, or the rules promulgated   thereunder, including Rule 144 under the Securities Act. The Purchaser agrees   that he or she will not dispose of the Purchased Shares unless and until he   or she has complied with all requirements of this Agreement applicable to the   disposition of Purchased Shares and he or she GDSVF&H\3433550.1 5 


    




 










has provided   the Company with written assurances, in substance and form satisfactory to   the Company, that (A) the proposed disposition does not require registration   of the Purchased Shares under the Securities Act or all appropriate action   necessary for compliance with the registration requirements of the Securities   Act or with any exemption from registration available under the Securities   Act (including Rule 144) has been taken and (B) the proposed disposition will   not result in the contravention of any transfer restrictions applicable to   the Purchased Shares under applicable state law. (v) The Purchaser has   received and has had access to such information as he or she considers   necessary or appropriate for deciding whether to invest in the Purchased   Shares, and the Purchaser has had an opportunity to ask questions and receive   answers from the Company regarding the terms and conditions of the issuance of   the Purchased Shares. (vi) The Purchaser is aware that his or her investment   in the Company is a speculative investment that has limited liquidity and is   subject to the risk of complete loss. The Purchaser is able, without   impairing his or her financial condition, to hold the Purchased Shares for an   indefinite period and to suffer a complete loss of his or her investment in   the Purchased Shares. (b) Securities Law Restrictions. Regardless of whether   the offer and sale of Shares under the Plan have been registered under the   Securities Act or have been registered or qualified under the securities laws   of any State or other relevant jurisdiction, the Company at its discretion   may impose restrictions upon the sale, pledge or other transfer of the   Purchased Shares (including the placement of appropriate legends on the stock   certificates (or electronic equivalent) or the imposition of stop-transfer   instructions) and may refuse (or may be required to refuse) to transfer   Shares acquired hereunder (or Shares proposed to be transferred in a   subsequent transfer) if, in the judgment of the Company, such restrictions,   legends or refusal are necessary or appropriate to achieve compliance with   the Securities Act or other relevant securities or other laws, including without   limitation under Regulation S of the Securities Act or pursuant to another   available exemption from registration. (c) Market Stand-Off. In connection   with any underwritten public offering by the Company of its equity securities   pursuant to an effective registration statement filed under the Securities   Act, including the Company’s initial public offering, the Purchaser or a   Transferee shall not directly or indirectly sell, make any short sale of,   loan, hypothecate, pledge, offer, grant or sell any option or other contract   for the purchase of, purchase any option or other contract for the sale of,   or otherwise dispose of or transfer, or agree to engage in any of the   foregoing transactions with respect to, any Purchased Shares without the   prior written consent of the Company or its managing underwriter. Such   restriction (the “Market Stand-Off”) shall be in effect for such period of   time following the date of the final prospectus for the offering as may be   requested by the Company or such underwriter. In no event, however, shall   such period exceed 180 days plus such additional period as may reasonably be   requested by the Company or such underwriter to accommodate regulatory   restrictions on (i) the publication or other distribution of research reports   or (ii) analyst recommendations and opinions, including (without limitation)   the restrictions set forth in Rule 2711(f)(4) of the National Association of   Securities Dealers and GDSVF&H\3433550.1 6 


    




 










Rule 472(f)(4)   of the New York Stock Exchange, as amended, or any similar successor rules.   The Market Stand-Off shall in any event terminate two years after the date of   the Company’s initial public offering. In the event of the declaration of a   stock dividend, a spin-off, a stock split, an adjustment in conversion ratio,   a recapitalization or a similar transaction affecting the Company’s   outstanding securities without receipt of consideration, any new, substituted   or additional securities which are by reason of such transaction distributed   with respect to any Shares subject to the Market Stand-Off, or into which   such Shares thereby become convertible, shall immediately be subject to the   Market Stand-Off. In order to enforce the Market Stand-Off, the Company may   impose stop-transfer instructions with respect to the Purchased Shares until   the end of the applicable stand-off period. The Company’s underwriters shall   be beneficiaries of the agreement set forth in this Subsection (c). This   Subsection (c) shall not apply to Shares registered in the public offering   under the Securities Act. (d) Rights of the Company. The Company shall not be   required to (i) transfer on its books any Purchased Shares that have been   sold or transferred in contravention of this Agreement or (ii) treat as the   owner of Purchased Shares, or otherwise to accord voting, dividend or   liquidation rights to, any transferee to whom Purchased Shares have been   transferred in contravention of this Agreement. SECTION 5. SUCCESSORS AND   ASSIGNS. Except as otherwise expressly provided to the contrary, the   provisions of this Agreement shall inure to the benefit of, and be binding   upon, the Company and its successors and assigns and be binding upon the   Purchaser and the Purchaser’s legal representatives, heirs, legatees,   distributees, assigns and transferees by operation of law, whether or not any   such person has become a party to this Agreement or has agreed in writing to   join herein and to be bound by the terms, conditions and restrictions hereof.   SECTION 6. NO RETENTION RIGHTS. Nothing in this Agreement or in the Plan   shall confer upon the Purchaser any right to continue providing services to   the Company for any period of specific duration or interfere with or   otherwise restrict in any way the rights of the Company (or any Parent or   Subsidiary employing or retaining the Purchaser) or of the Purchaser, which   rights are hereby expressly reserved by each, to terminate his or her Service   at any time and for any reason, with or without cause. SECTION 7. TAX ELECTION.   The acquisition of the Purchased Shares may result in adverse tax   consequences that may be avoided or mitigated by filing an election under   Code Section 83(b). Such election may be filed only within 30 days after the   date of purchase set forth in the Summary of Stock Purchase. The form for   making the Code Section 83(b) election is attached to this Agreement as an   Exhibit. The Purchaser should consult with his or her tax advisor to   determine the tax consequences of acquiring the Purchased Shares and the   advantages and disadvantages of filing the Code Section 83(b) election. The   Purchaser acknowledges that it is his or her sole GDSVF&H\3433550.1 7 


    




 










responsibility,   and not the Company’s, to file a timely election under Code Section 83(b),   even if the Purchaser requests the Company or its representatives to make   this filing on his or her behalf. SECTION 8. LEGENDS. All certificates   evidencing Purchased Shares shall bear the following legends: “THE SHARES   REPRESENTED HEREBY MAY NOT BE SOLD, ASSIGNED, TRANSFERRED, ENCUMBERED OR IN   ANY MANNER DISPOSED OF, EXCEPT IN COMPLIANCE WITH THE TERMS OF A WRITTEN   AGREEMENT BETWEEN THE COMPANY AND THE REGISTERED HOLDER OF THE SHARES (OR THE   PREDECESSOR IN INTEREST TO THE SHARES). SUCH AGREEMENT GRANTS TO THE COMPANY   CERTAINRIGHTSOFFIRSTREFUSALUPONANATTEMPTED TRANSFER OF THE SHARES AND CERTAIN   REPURCHASE RIGHTS UPONTERMINATIONOFSERVICEWITHTHECOMPANY.IN ADDITION,   TRANSFER THESHARESARESUBJECTTORESTRICTIONSON FOR A LIMITED PERIOD FOLLOWING   THE EFFECTIVE DATE OF THE UNDERWRITTENPUBLICOFFERING OF THE COMPANY’S   SECURITIES AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF BY THE HOLDER WITHOUT   THE CONSENT OF THE COMPANY OR THE MANAGING UNDERWRITER. THE SECRETARY OF THE   COMPANY WILL UPON WRITTEN REQUEST FURNISH A COPY OF SUCH AGREEMENT TO THE   HOLDER HEREOF WITHOUT CHARGE.” All certificates evidencing the Purchased   Shares acquired under this Agreement in an unregistered transaction shall   bear the following legend (and such other restrictive legends as are required   or deemed advisable under the provisions of any applicable law): “THE SHARES   REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,   AS AMENDED (THE “ACT”) OR ANY SECURITIES LAWS OF ANY U.S. STATE, AND MAY NOT   BE SOLD, REOFFERED, PLEDGED, ASSIGNED, ENCUMBERED OR OTHERWISE TRANSFERREDOR   DISPOSEDWITHOUT ANEFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR AN OPINION   OF COUNSEL, SATISFACTORY TO THE COMPANY AND ITS COUNSEL, THAT SUCH   REGISTRATION IS NOT REQUIRED. IN THE ABSENCE OF REGISTRATION OR THE   AVAILABILITY (CONFIRMED BY OPINION OF COUNSEL) OF AN ALTERNATIVE EXEMPTION   FROM REGISTRATION UNDER THE ACT(INCLUDINGWITHOUTLIMITATION IN ACCORDANCE   SHARES MAY ENCUMBERED WITH REGULATION S UNDER THE ACT), THESE NOT BE SOLD,   REOFFERED, PLEDGED, ASSIGNED, OR OTHERWISE TRANSFERRED OR DISPOSED OF.   HEDGING TRANSACTIONS INVOLVING THESE SHARES MAY NOT BE CONDUCTED UNLESS IN   COMPLIANCE WITH THE ACT.” GDSVF&H\3433550.1 8 


    




 










If required by   the authorities of any State in connection with the issuance of the Purchased   Shares, the legend or legends required by such State authorities shall also   be endorsed on all such certificates. SECTION 9. MISCELLANEOUS PROVISIONS.   (a) Choice of Law. This Agreement shall be governed by, and construed in   accordance with, the laws of the State of Delaware, as such laws are applied   to contracts entered into and performed in such State. (b) Notice. Any notice   required by the terms of this Agreement shall be given in writing. It shall   be deemed effective upon (i) personal delivery, (ii) deposit with the United   States Postal Service, by registered or certified mail, with postage and fees   prepaid, (iii) deposit with Federal Express Corporation, with shipping   charges prepaid or (iv) deposit with any internationally recognized express   mail courier service. Notice shall be addressed to the Company at its   principal executive office and to the Purchaser at the address that he or she   most recently provided to the Company in accordance with this Subsection (b).   (c) Entire Agreement. The Summary of Stock Purchase, this Agreement and the   Plan constitute the entire contract between the parties hereto with regard to   the subject matter hereof. They supersede any other agreements,   representations or understandings (whether oral or written and whether   express or implied) that relate to the subject matter hereof. SECTION 10.   ACKNOWLEDGEMENTS OF THE PURCHASER. In addition to the other terms, conditions   and restrictions imposed on the Shares acquired pursuant to this Agreement,   the Purchaser expressly acknowledges being subject to Sections 2 (Right of   Repurchase), 3 (Right of First Refusal) and 4 (Other Restrictions on   Transfer, including without limitation the Market Stand-Off), as well as the   following provisions: (a) Waiver of Statutory Information Rights. The   Purchaser acknowledges and agrees that, until the first sale of the Company’s   Stock to the general public pursuant to a registration statement filed under   the Securities Act, he or she will be deemed to have waived any rights the Purchaser   might otherwise have had under Section 220 of the Delaware General   Corporation Law (or under similar rights under other applicable law) to   inspect for any proper purpose and to make copies and extracts from the   Company’s stock ledger, a list of its stockholders and its other books and   records or the books and records of any subsidiary. This waiver applies only   in the Purchaser’s capacity as a stockholder and does not affect any other   inspection rights the Purchaser may have under other law or pursuant to a   written agreement with the Company. (b) Plan Discretionary.The Purchaser   understands and acknowledges that (i) the Plan is entirely discretionary,   (ii) the Company and the Purchaser’s employer have reserved the right to   amend, suspend or terminate the Plan at any time, (iii) the transfer of the   Purchased Shares does not in any way create any contractual or other right to   receive additional awards under the Plan at any time or in any amount and   (iv) all determinations with respect to GDSVF&H\3433550.1 9 


    




 










any additional   awards, including (without limitation) the times when awards will be granted,   the number of Shares offered and the vesting schedule, will be at the sole   discretion of the Company. (c) Termination of Service.The Purchaser   understands and acknowledges that participation in the Plan ceases upon   termination of his or her Service for any reason, except as may explicitly be   provided otherwise in the Plan or this Agreement. (d)Extraordinary   Compensation. The value of the Purchased Shares shall be an extraordinary   item of compensation outside the scope of the Purchaser’s employment   contract, if any, and shall not be considered a part of his or her normal or   expected compensation for purposes of calculating severance, resignation,   redundancy or end-of-service payments, bonuses, long-service awards, pension   or retirement benefits or similar payments. (e) Authorization to Disclose.   The Purchaser hereby authorizes and directs the Purchaser’s employer to   disclose to the Company or any Subsidiary any information regarding the   Purchaser’s employment, the nature and amount of the Purchaser’s compensation   and the fact and conditions of the Purchaser’s participation in the Plan, as   the Purchaser’s employer deems necessary or appropriate to facilitate the   administration of the Plan. (f) Personal Data Authorization. The Purchaser   consents to the collection, use and transfer of personal data as described in   this Subsection (f). The Purchaser understands and acknowledges that the   Company, the Purchaser’s employer and the Company’s other Subsidiaries hold   certain personal information regarding the Purchaser for the purpose of   managing and administering the Plan, including (without limitation) the   Purchaser’s name, home address, telephone number, date of birth, social   insurance number, salary, nationality, job title, any Shares or directorships   held in the Company and details of all options or any other entitlements to   Shares awarded, canceled, exercised, vested, unvested or outstanding in the Purchaser’s   favor (the “Data”). The Purchaser further understands and acknowledges that   the Company and/or its Subsidiaries will transfer Data among themselves as   necessary for the purpose of implementation, administration and management of   the Purchaser’s participation in the Plan and that the Company and/or any   Subsidiary may each further transfer Data to any third party assisting the   Company in the implementation, administration and management of the Plan. The   Purchaser understands and acknowledges that the recipients of Data may be   located in the United States or elsewhere. The Purchaser authorizes such   recipients to receive, possess, use, retain and transfer Data, in electronic   or other form, for the purpose of administering the Purchaser’s participation   in the Plan, including a transfer to any broker or other third party with   whom the Purchaser elects to deposit Shares acquired under the Plan of such   Data as may be required for the administration of the Plan and/or the   subsequent holding of Shares on the Purchaser’s behalf. The Purchaser may, at   any time, view the Data, require any necessary modifications of Data or   withdraw the consents set forth in this Subsection (f) by contacting the   Company in writing. SECTION 11. DEFINITIONS. (a) “Agreement” shall mean this   Stock Purchase Agreement. GDSVF&H\3433550.1 10 


    




 










(b) “Board of   Directors” shall mean the Board of Directors of the Company, as constituted   from time to time or, if a Committee has been appointed, such Committee. (c)   “Company” shall mean Akouos, Inc., a Delaware corporation. (d) “Immediate   Family” shall mean any child, stepchild, grandchild, parent, stepparent,   grandparent, spouse, sibling, mother-in-law, father-in-law, son-in-law,   daughter-in-law, brother-in-law or sister-in-law and shall include adoptive   relationships. (e) “Plan” shall mean the Akouos, Inc. 2016 Stock Plan, as   amended. (f) “Purchased Shares” shall mean the Shares purchased by the   Purchaser pursuant to this Agreement. (g) “Purchase Price” shall mean the   amount for which one Share may be purchased pursuant to this Agreement, as   specified in the Summary of Stock Purchase. (h) “Purchaser” shall mean the   person named in the Summary of Stock Purchase. (i) commencing on the   “Repurchase Period” shall mean a period of 90 consecutive days date when the   Purchaser’s Service terminates for any reason, including (without limitation)   death or disability. (j)“Restricted Share” shall mean a Purchased Share that   is subject to the Right of Repurchase. (k) “Right of First Refusal” shall   mean the Company’s right of first refusal described in Section 3. (l) “Right   of Repurchase” shall mean the Company’s right of repurchase described in   Section 2. (m) “Service” shall mean service as an Employee, Outside Director   or Consultant. (n) “Transferee” shall mean any person to whom the Purchaser   has directly or indirectly transferred any Purchased Share. (o) “Transfer   Notice” shall mean the notice of a proposed transfer of Purchased Shares   described in Section 3. GDSVF&H\3433550.1 11 


    




 










EXHIBIT I   SECTION 83(b) ELECTION The undersigned taxpayer hereby elects, pursuant to   Section 83(b) of the Internal Revenue Code of 1986, as amended, and pursuant   to Treasury Regulations Section 1.83-2, to include in gross income as   compensation for services the excess (if any) of the fair market value of the   shares described below over an amount paid for those shares. (a) The taxpayer   who performed the services is: Name: Address: Social Security No.: (b) The   property with respect to which the election is made is common stock of   Akouos, Inc. The property was transferred to the taxpayer on _ . shares of   the (c) (d) (e) The taxable year for which the election is made is the   calendar year . The property is subject to a repurchase right pursuant to   which the issuer has the right to acquire the property if for any reason   taxpayer’s service with the issuer terminates. The issuer’s repurchase right   lapses in a series of installments over a four-year period ending on . (f)   The fair market value of such property at the time of transfer (determined   without regard to any restriction other than a restriction that by its terms   will never lapse) is $_ per share x shares = $ . (g) For the property   transferred, the taxpayer paid $ per share × shares = $ . (h) (i) The amount   to include in gross income is $0. A copy of this statement was furnished to   Akouos, Inc., for whom taxpayer rendered the services underlying the transfer   of such property. This statement is executed on , . (j) Signature of Spouse   (if any) Signature of Taxpayer Within 30 days after the date of transfer of   the property, this election must be filed with the Internal Revenue Service   office where the taxpayer files his or her annual federal income tax return.   The filing should be made by registered or certified mail, return receipt   requested. The taxpayer must deliver a completed copy to the Company.   GDSVF&H\3433550.1