INVESTORS RIGHTS AGREEMENT

Exhibit 10.9

EXECUTION VERSION

INVESTORS’ RIGHTS AGREEMENT

THIS INVESTORS’ RIGHTS AGREEMENT (this “Agreement”) is made as of August 7, 2017 by and among KRYSTAL BIOTECH, INC., a Delaware corporation (the “Company”) the investors listed on Schedule A hereto (each an “Investor” and collectively the “Investors”) and those persons listed on Schedule B hereto (each, a “Founder”, and collectively, the “Founders”).

RECITALS

A. The Investors and the Company are parties to that certain Series A Preferred Stock Purchase Agreement dated as of the date hereof (the “Series A Purchase Agreement”) relating to the issue and sale of shares of Series A Preferred Stock of the Company (the “Series A Preferred Stock”).

B. The obligations of the Company and the Investors under the Series A Purchase Agreement are conditioned, among other things, upon the execution and delivery of this Agreement by the Investors and the Company.

NOW, THEREFORE, in consideration of the mutual premises and covenants set forth herein, the parties hereto agree as follows:

1. Registration Rights. The Company covenants and agrees as follows:

1.1 Definitions. For purposes of this Section 1:

(a) The term “Act” means the Securities Act of 1933, as amended.

(b) The term “Form S-3” means such form under the Act as in effect on the date hereof or any registration form under the Act subsequently adopted by the SEC that permits inclusion or incorporation of substantial information by reference to other documents filed by the Company with the SEC.

(c) The term “Holder” means any person owning or having the right to acquire Registrable Securities or any assignee thereof in accordance with Section 1.11 hereof.

(d) The term “Initial Public Offering” means the first underwritten public offering of securities of the Company pursuant to an effective registration statement under the Act (other than a registration statement relating either to the sale of securities to employees of the Company pursuant to a stock option, stock purchase or similar plan or an SEC Rule 145 transaction).

(e) The term “1934 Act” means the Securities Exchange Act of 1934, as amended.

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(f) The term “Preferred Stock” means, collectively, shares of the Company’s the Series Seed Preferred Stock, Series A Preferred Stock, Series A-1 Preferred Stock, and Series A-2 Preferred Stock.

(g) The term “register,” “registered,” and “registration” refer to a registration effected by preparing and filing a registration statement or similar document in compliance with the Act, and the declaration or ordering of effectiveness of such registration statement or document.

(h) The term “Registrable Securities” means (i) the Common Stock issuable or issued upon conversion of the Company’s Series Seed Preferred Stock, Series A Preferred Stock, Series A-1 Preferred Stock and Series A-2 Preferred Stock, (ii) with respect to the rights granted to Holders pursuant to Section 1.3 hereof only, any Common Stock held by the Founders or Common Stock issuable upon the exercise by them of any option, warrant or other right to acquire such Common Stock, and (iii) any Common Stock of the Company issued as (or issuable upon the conversion or exercise of any warrant, right or other security that is issued as) a dividend or other distribution with respect to, or in exchange for, or in replacement of, the shares referenced in (i) above, excluding in all cases, however, any Registrable Securities sold by a person (x) in a transaction in which his, her or its rights under this Section 1 are not assigned, (y) pursuant to a registration statement under the Act that has been declared effective and such Registrable Securities have been disposed of pursuant to such effective registration statement, or (z) in a transaction in which such Registrable Securities are sold pursuant to Rule 144 (or any similar provision then in force) under the Act.

(i) The number of shares of “Registrable Securities then outstanding” shall be determined by the number of shares of Common Stock outstanding that are, and the number of shares of Common Stock issuable pursuant to then exercisable or convertible securities that are, Registrable Securities.

(j) The term “Series A-1 Preferred Stock” means shares of the Company’s Series A-1 Preferred Stock, par value $0.00001 per share.

(k) The term “Series A-2 Preferred Stock” means shares of the Company’s Series A-2 Preferred Stock, par value $0.00001 per share.

(l) The term “Series Seed Preferred Stock” means shares of the Company’s Series Seed Preferred Stock, par value $0.00001 per share.

(m) The term “SEC” shall mean the Securities and Exchange Commission.

1.2 Request for Registration.

(a) Subject to the conditions of this Section 1.2, if the Company shall receive at any time after the date which is six (6) months after the effective date of the Initial Public Offering, a written request from the Holders of a majority of the Registrable Securities then outstanding (the “Initiating Holders”) that the Company file a registration statement under the Act covering the registration of Registrable Securities at an aggregate price to the public (net

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of any underwriters’ discounts or commissions) of not less than $5,000,000, then the Company shall, within twenty (20) days of the receipt thereof, give written notice of such request to all Holders, and subject to the limitations of this Section 1.2, use commercially reasonable efforts to effect, as soon as practicable, the registration under the Act of all Registrable Securities that the Holders request to be registered in a written request received by the Company within twenty (20) days of the mailing of the Company’s notice pursuant to this Section 1.2(a).

(b) If the Initiating Holders intend to distribute the Registrable Securities covered by their request by means of an underwriting, they shall so advise the Company as a part of their request made pursuant to this Section 1.2 and the Company shall include such information in the written notice referred to in this Section 1.2(a). In such event the right of any Holder to include its Registrable Securities in such registration shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting (unless otherwise mutually agreed by a majority in interest of the Initiating Holders and such Holder) to the extent provided herein. All Holders proposing to distribute their securities through such underwriting shall enter into an underwriting agreement in customary form with the underwriter or underwriters selected for such underwriting by the Company.

(c) In addition, the Company shall not be required to effect a registration pursuant to this Section 1.2:

(i) after the Company has effected one (1) registration pursuant to this Section 1.2, and such registrations have been declared or ordered effective;

(ii) during the period starting with the date ninety (90) days prior to the Company’s good faith estimate of the date of the filing of, and ending on a date one hundred eighty (180) days following the effective date of, a Company-initiated registration subject to Section 1.3, provided that the Company furnishes to the Initiating Holders a notice of such good faith estimate within thirty (30) days of receipt of the request from the Initiating Holders and the Company is actively employing in good faith all reasonable efforts to cause such registration statement to become effective;

(iii) if the Initiating Holders propose to dispose of Registrable Securities that may be registered on Form S-3 pursuant to Section 1.4;

(iv) if the Company shall furnish to Holders requesting a registration pursuant to this Section 1.2, a certificate signed by the Company’s Chief Executive Officer or Chairman of the Board stating that in the good faith judgment of the Board of Directors of the Company, it would be materially detrimental to the Company and its stockholders for such registration to be effected at such time, in which event the Company shall have the right to defer such filing for a period of not more than ninety (90) days after receipt of the request of the Initiating Holders , provided that such right to delay a request shall be exercised by the Company not more than once in any twelve (12)-month period; or

(v) in any particular jurisdiction in which the Company would be required to execute a general consent to service of process in effecting such registration, unless the Company is already subject to service in such jurisdiction and except as may be required under the Act.

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1.3 Company Registration.

(a) If (but without any obligation to do so) the Company proposes to register (including for this purpose a registration effected by the Company for stockholders other than the Holders) any of its stock or other securities under the Act in connection with the public offering of such securities (other than a registration relating solely to the sale of securities to participants in a Company stock plan, a registration relating to a corporate reorganization or other transaction under Rule 145 of the Act, a registration on any form that does not include substantially the same information as would be required to be included in a registration statement covering the sale of the Registrable Securities, or a registration in which the only Common Stock being registered is Common Stock issuable upon conversion of debt securities that are also being registered), the Company shall, at such time, promptly give each Holder written notice of such registration. Upon the written request of each Holder given within twenty (20) days after mailing of such notice by the Company, the Company shall, subject to the provisions of Section 1.5(e), use commercially reasonable efforts to cause to be registered under the Act all of the Registrable Securities that each such Holder has requested to be registered.

(b) Right to Terminate Registration. The Company shall have the right to terminate or withdraw any registration initiated by it under this Section 1.3 prior to the effectiveness of such registration whether or not any Holder has elected to include securities in such registration. The expenses of such withdrawn registration shall be borne by the Company in accordance with Section 1.7 hereof.

1.4 Form S-3 Registration. In case the Company shall receive from any Holder or Holders of the Registrable Securities then outstanding a written request or requests that the Company effect a registration on Form S-3 and any related qualification or compliance with respect to all or a part of the Registrable Securities owned by such Holder or Holders, the Company shall:

(a) promptly give written notice of the proposed registration, and any related qualification or compliance, to all other Holders; and

(b) use commercially reasonable efforts to effect, as soon as practicable, such registration and all such qualifications and compliances as may be so requested and as would permit or facilitate the sale and distribution of all or such portion of such Holders’ Registrable Securities as are specified in such request, together with all or such portion of the Registrable Securities of any other Holders joining in such request as are specified in a written request given within fifteen (15) days after receipt of such written notice from the Company, provided, however, that the Company shall not be obligated to effect any such registration, qualification or compliance, pursuant to this Section 1.4:

(i) if Form S-3 is not available for such offering by the Holders;

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(ii) if the Holders, together with the holders of any other securities of the Company entitled to inclusion in such registration, propose to sell Registrable Securities and such other securities (if any) at an aggregate price to the public (net of any underwriters’ discounts or commissions) of less than $2,000,000;

(iii) if the Company shall furnish to the Holders a certificate signed by the Chief Executive Officer or Chairman of the Board of the Company stating that in the good faith judgment of the Board of Directors of the Company, it would be materially detrimental to the Company and its stockholders for such Form S-3 registration to be effected at such time, in which event the Company shall have the right to defer the filing of the Form S-3 registration statement for a period of not more than ninety (90) days after receipt of the request of the Holder or Holders under this Section 1.4, provided, however, that the Company shall not utilize this right more than once in any twelve (12) month period;

(iv) if the Company has, within the twelve (12) month period preceding the date of such request, already effected two registrations on Form S-3 for the Holders pursuant to this Section 1.4; or

(v) in any particular jurisdiction in which the Company would be required to qualify to do business, where not otherwise required, or to execute a general consent to service of process in effecting such registration, qualification or compliance.

(c) Subject to the foregoing, the Company shall use commercially reasonable efforts to file a registration statement covering the Registrable Securities and other securities so requested to be registered as soon as practicable after receipt of the request or requests of the Holders. Registrations effected pursuant to this Section 1.4 shall not be counted as requests for registration effected pursuant to Section 1.2 or Section 1.3.

1.5 Obligations of the Company. Whenever required under this Section 1 to effect the registration of any Registrable Securities, the Company shall, as expeditiously as reasonably possible:

(a) prepare and file with the SEC a registration statement with respect to such Registrable Securities and use commercially reasonable efforts to cause such registration statement to become effective, and, upon the request of the Holders of a majority of the Registrable Securities registered thereunder, keep such registration statement effective for a period of up to 120 days or, if earlier, until the distribution contemplated in the Registration Statement has been completed; provided, however, that (i) such 120- day period shall be extended for a period of time equal to the period the Holder refrains from selling any securities included in such registration at the request of an underwriter of Common Stock (or other securities) of the Company; and (ii) in the case of any registration of Registrable Securities on Form S-3 which are intended to be offered on a continuous or delayed basis, such 120-day period shall be extended, if necessary, to keep the registration statement effective until all such Registrable Securities are sold, provided that Rule 415, or any successor rule under the Act, permits an offering on a continuous or delayed basis, and provided further that applicable rules under the Act governing the obligation to file a post-effective amendment permit, in lieu of filing a post-effective amendment which (I) includes any prospectus required by Section 10(a)(3) of

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the Act or (II) reflects facts or events representing a material or fundamental change in the information set forth in the registration statement, the incorporation by reference of information required to be included in (I) and (II) above to be contained in periodic reports filed pursuant to Section 13 or 15(d) of the 1934 Act in the registration statement;

(b) prepare and file with the SEC such amendments and supplements to such registration statement and the prospectus used in connection with such registration statement as may be necessary to comply with the provisions of the Act with respect to the disposition of all securities covered by such registration statement;

(c) furnish to each Holder (i) a draft copy of the registration statement, and (ii) such numbers of copies of a prospectus, including a preliminary prospectus, in conformity with the requirements of the Act, and such other documents as it may reasonably request in order to facilitate the disposition of Registrable Securities owned by it;

(d) use commercially reasonable efforts to register and qualify the securities covered by such registration statement under such other securities or “blue sky” laws of such jurisdictions as shall be reasonably requested by the Holders, provided that the Company shall not be required in connection therewith or as a condition thereto to qualify to do business, where not otherwise required, or to file a general consent to service of process in any such states or jurisdictions, unless the Company is already subject to service in such jurisdiction and except as may be required by the Act;

(e) in the event of any underwritten public offering, enter into and perform its obligations under an underwriting agreement, in usual and customary form, with the managing underwriter of such offering. Each Holder participating in such underwriting shall also enter into and perform its obligations under such an agreement. In connection with any offering involving an underwriting of shares of the Company’s capital stock, the Company shall not be required to include any of the Holders’ securities in such underwriting unless they accept the terms of the underwriting as agreed upon between the Company and the underwriters selected by the Company and enter into an underwriting agreement in customary form with an underwriter or underwriters selected by the Company. If the total amount of securities, including Registrable Securities, requested by stockholders to be included in such offering exceeds the amount of securities sold other than by the Company that the underwriters determine in their sole discretion is compatible with the success of the offering, then subject to Section 1.2 above, the Company shall be required to include in the offering only that number of such securities, including Registrable Securities, that the underwriters determine in their sole discretion will not jeopardize the success of the offering (the securities so included to be apportioned pro rata among the selling stockholders according to the total amount of securities entitled to be included therein owned by each selling stockholder or in such other proportions as shall mutually be agreed to by such selling stockholders), but in no event shall the amount of securities of the selling Holders included in the offering be reduced below 20% of the total amount of securities included in such offering, unless such offering is the Initial Public Offering of the Company’s securities, in which case the selling stockholders may be excluded if the underwriters make the determination described above. For purposes of the preceding parenthetical concerning apportionment, for any selling stockholder that is a Holder of Registrable Securities and that is a partnership or corporation, the partners, retired partners and stockholders of such Holder, or the

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estates and family members of any such partners and retired partners and any trusts for the benefit of any of the foregoing persons shall be deemed to be a single “selling stockholder,” and any pro rata reduction with respect to such “selling stockholder” shall be based upon the aggregate amount of Registrable Securities owned by all entities and individuals included in such “selling stockholder,” as defined in this sentence;

(f) notify each Holder of Registrable Securities covered by such registration statement, at any time when a prospectus relating thereto is required to be delivered under the Act, of (i) the issuance of any stop order by the SEC in respect of such registration statement, or (ii) 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 the light of the circumstances then existing;

(g) cause all such Registrable Securities registered pursuant hereunder to be listed on each securities exchange on which similar securities issued by the Company are then listed;

(h) provide a transfer agent and registrar for all Registrable Securities registered pursuant hereunder and a CUSIP number for all such Registrable Securities, in each case not later than the effective date of such registration; and

(i) Use commercially reasonable efforts to furnish, at the request of any Holder requesting registration of Registrable Securities pursuant to this Section 1, on the date that such Registrable Securities are delivered to the underwriters for sale in connection with a registration pursuant to this Section 1, if such securities are being sold through underwriters, or, if such securities are not being sold through underwriters, on the date that the registration statement with respect to such securities becomes effective, an opinion, dated as of such date, of the counsel representing the Company for the purposes of such registration, in form and substance as is customarily given to underwriters in an underwritten public offering and reasonably satisfactory to a majority in interest of the Holders requesting registration, addressed to the underwriters and to the Holders requesting registration of Registrable Securities.

1.6 Information from Holder.

(a) It shall be a condition precedent to the obligations of the Company to take any action pursuant to this Section 1 with respect to the Registrable Securities of any selling Holder that such Holder shall furnish to the Company such information regarding itself, the Registrable Securities held by it, and the intended method of disposition of such securities as shall be reasonably required to effect the registration of such Holder’s Registrable Securities.

(b) The Company shall have no obligation with respect to any registration requested pursuant to Section 1.2 if, due to the operation of Section 1.6(a), the number of shares of the Registrable Securities to be included in the registration does not equal or exceed the number of shares required to originally trigger the Company’s obligation to initiate such registration as specified in Section 1.2(a).

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1.7 Expenses of Registration.

(a) All expenses other than underwriting discounts and commissions incurred in connection with registrations, filings or qualifications pursuant to Sections 1.2 and 1.3 and 1.4, including, without limitation, all registration, filing and qualification fees (including “blue sky” fees), printers’ and accounting fees, fees and disbursements of counsel for the Company shall be borne by the Company (including fees and disbursements of counsel for the Company in its capacity as counsel to the selling Holders hereunder; if Company counsel does not make itself available for this purpose, the Company will pay the reasonable fees and disbursements of one counsel for the selling Holders not to exceed $25,000). Notwithstanding the foregoing, the Company shall not be required to pay for any expenses of any registration proceeding begun pursuant to Section 1.2 or Section 1.4 if the registration request is subsequently withdrawn at the request of the Holders of a majority of the Registrable Securities to be registered (in which case all participating Holders shall bear such expenses pro rata based upon the number of Registrable Securities that were to be registered in the withdrawn registration), unless, in the case of a registration requested under Section 1.2, the Holders of a majority of the Registrable Securities agree to forfeit their right to one demand registration pursuant to Section 1.2.

1.8 Delay of Registration. No Holder shall have any right to obtain or seek an injunction restraining or otherwise delaying any such registration as the result of any controversy that might arise with respect to the interpretation or implementation of this Section 1.

1.9 Indemnification. In the event any Registrable Securities are included in a registration statement under this Section 1:

(a) To the extent permitted by law, the Company will indemnify and hold harmless each Holder, any underwriter (as defined in the Act) for such Holder and each person, if any, who controls such Holder or underwriter, within the meaning of the Act or the 1934 Act, against any losses, claims, damages or liabilities (joint or several) to which they may become subject under the Act, the 1934 Act or any state securities laws, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any of the following statements, omissions or violations (collectively a “Violation”): (i) any untrue statement or alleged untrue statement of a material fact contained in such registration statement, including any preliminary prospectus or final prospectus contained therein or any amendments or supplements thereto, (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 (iii) any violation or alleged violation by the Company of the Act, the 1934 Act, any state securities laws or any rule or regulation promulgated under the Act, the 1934 Act or any state securities laws; and the Company will reimburse each such Holder, underwriter or controlling person for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability or action; provided, however, that the indemnity agreement contained in this Section 1.9(a) shall not apply to amounts paid in settlement of any such loss, claim, damage, liability or action if such settlement is effected without the consent of the Company, nor shall the Company be liable in any such case for any such loss, claim, damage, liability or action to the extent that it arises out of or is based upon a Violation that occurs in reliance upon and in conformity with information furnished expressly for

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use in connection with such registration by any such Holder, underwriter or controlling person; provided further, however, that the foregoing indemnity agreement with respect to any preliminary prospectus shall not inure to the benefit of any Holder or underwriter, or any person controlling such Holder or underwriter, from whom the person asserting any such losses, claims, damages or liabilities purchased shares in the offering, if a copy of the prospectus (as then amended or supplemented if the Company shall have furnished any amendments or supplements thereto) was not sent or given by or on behalf of such Holder or underwriter to such person, if required by law so to have been delivered, at or prior to the written confirmation of the sale of the shares to such person, and if the prospectus (as so amended or supplemented) would have cured the defect giving rise to such loss, claim, damage or liability.

(b) To the extent permitted by law, each selling Holder will indemnify and hold harmless the Company, each of its directors, each of its officers who has signed the registration statement, each person, if any, who controls the Company within the meaning of the Act, any underwriter, any other stockholder selling securities in such registration statement and any controlling person of any such underwriter or other stockholder, against any losses, claims, damages or liabilities (joint or several) to which any of the foregoing persons may become subject, under the Act, the 1934 Act or any state securities laws, insofar as such losses, claims, damages or liabilities (or actions in respect thereto) arise out of or are based upon any Violation, in each case to the extent (and only to the extent) that such Violation occurs in reliance upon and in conformity with information furnished by such Holder expressly for use in connection with such registration; and each such Holder will reimburse any person intended to be indemnified pursuant to this Section 1.9(b) for any legal or other expenses reasonably incurred by such person in connection with investigating or defending any such loss, claim, damage, liability or action; provided, however, that the indemnity agreement contained in this Section 1.9(b) shall not apply to amounts paid in settlement of any such loss, claim, damage, liability or action if such settlement is effected without the consent of the Holder, provided that in no event shall any indemnity under this Section 1.9(b) exceed the net proceeds from the offering received by such Holder.

(c) Promptly after receipt by an indemnified party under this Section 1.9 of actual knowledge of the commencement of any action (including any governmental action), such indemnified party will, if a claim in respect thereof is to be made against any indemnifying party under this Section 1.9, deliver to the indemnifying party a written notice of the commencement thereof and the indemnifying party shall have the right to participate in, and, to the extent the indemnifying party so desires, jointly with any other indemnifying party similarly noticed, to assume the defense thereof with counsel mutually satisfactory to the parties; provided, however, that an indemnified party (together with all other indemnified parties that may be represented without conflict by one counsel) shall have the right to retain one separate counsel, with the fees and expenses to be paid by the indemnifying party, if representation of such indemnified party by the counsel retained by the indemnifying party would be inappropriate due to actual or potential differing interests between such indemnified party and any other party represented by such counsel in such proceeding. The failure to deliver written notice to the indemnifying party within a reasonable time of the commencement of any such action, if prejudicial to its ability to defend such action, shall relieve such indemnifying party of any liability to the indemnified party under this Section 1.9 to the extent of such prejudice, but the omission to so deliver written notice to the indemnifying party will not relieve it of any liability that it may have to any indemnified party otherwise than under this Section 1.9.

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(d) If the indemnification provided for in this Section 1.9 is held by a court of competent jurisdiction to be unavailable to an indemnified party with respect to any loss, liability, claim, damage or expense referred to herein, then the indemnifying party, in lieu of indemnifying such indemnified party hereunder, shall contribute to the amount paid or payable by such indemnified party as a result of such loss, liability, claim, damage or expense in such proportion as is appropriate to reflect the relative fault of and the relative benefits received by the indemnifying party on the one hand and of the indemnified party on the other in connection with the statements or omissions that resulted in such loss, liability, claim, damage or expense, as well as any other relevant equitable considerations, provided that no person guilty of fraud shall be entitled to contribution. The relative fault of the indemnifying party and of the indemnified party shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission to state a material fact relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information, and opportunity to correct or prevent such statement or omission. The relative benefits received by the indemnifying party and the indemnified party shall be determined by reference to the net proceeds and underwriting discounts and commissions from the offering received by each such party. In no event shall any contribution under this Section 1.9(d) exceed the net proceeds from the offering received by such Holder, less any amounts paid under Section 1.9(b).

(e) Notwithstanding the foregoing, to the extent that the provisions on indemnification and contribution contained in the underwriting agreement entered into in connection with the underwritten public offering are in conflict with the foregoing provisions, the provisions in the underwriting agreement shall control.

(f) The obligations of the Company and Holders under this Section 1.9 shall survive the completion of any offering of Registrable Securities in a registration statement under this Section 1, and otherwise.

1.10 Reports Under Securities Exchange Act of 1934. With a view to making available to the Holders the benefits of Rule 144 promulgated under the Act and any other rule or regulation of the SEC that may at any time permit a Holder to sell securities of the Company to the public without registration or pursuant to a registration on Form S-3, the Company agrees to:

(a) make and keep public information available, as those terms are understood and defined in SEC Rule 144, at all times after ninety (90) days after the effective date of the Initial Public Offering;

(b) file with the SEC in a timely manner all reports and other documents required of the Company under the Act and the 1934 Act; and

(c) furnish to any Holder, so long as the Holder owns any Registrable Securities, forthwith upon request (i) a written statement by the Company that it has complied with the reporting requirements of SEC Rule 144 (at any time after ninety (90) days after the

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effective date of the Initial Public Offering), the Act and the 1934 Act (at any time after it has become subject to such reporting requirements), or that it qualifies as a registrant whose securities may be resold pursuant to Form S-3 (at any time after it so qualifies), (ii) a copy of the most recent annual or quarterly report of the Company and such other reports and documents so filed by the Company, and (iii) such other information as may be reasonably requested in availing any Holder of any rule or regulation of the SEC that permits the selling of any such securities without registration or pursuant to such form.

1.11 Assignment of Registration Rights. The rights to cause the Company to register Registrable Securities pursuant to this Section 1 may be assigned (but only with all related obligations) by a Holder to (i) any of its partners, retired partners, members or retired members, (ii) a Holder’s immediate family member (spouse or child) or trust for the benefit of an individual Holder, provided: (a) the Company is, within a reasonable time after such transfer, furnished with written notice of the name and address of such transferee or assignee and the securities with respect to which such registration rights are being assigned; (b) such transferee or assignee agrees in writing (a copy of which writing is provided to the Company at the time of transfer) to be bound by and subject to the terms and conditions of this Agreement, including without limitation the provisions of Section 1.13 below; and (c) such assignment shall be effective only if immediately following such transfer the further disposition of such securities by the transferee or assignee is restricted under the Act. For the purposes of determining the number of shares of Registrable Securities held by a transferee or assignee, the holdings of transferees and assignees of a partnership who are partners or retired partners of such partnership (including spouses and ancestors, lineal descendants and siblings of such partners or spouses who acquire Registrable Securities by gift, will or intestate succession) shall be aggregated together and with the partnership; provided that all assignees and transferees who would not qualify individually for assignment of registration rights shall have a single attorney-in-fact for the purpose of exercising any rights, receiving notices or taking any action under this Section 1.

1.12 “Market Stand-Off” Agreement. Each Holder hereby agrees that it will not, directly or indirectly, without the prior written consent of the Company and the managing underwriter, during the period commencing on the date of the final prospectus relating to the Initial Public Offering and ending on the date specified by the Company and the managing underwriter (such period not to exceed one hundred eighty (180) days) (i) lend, offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock (whether such shares or any such securities are then owned by the Holder or are thereafter acquired), or (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise; provided, however, that such period may be extended to such longer period as the Company or the managing underwriter may request in order to facilitate compliance with, to the extent applicable, Financial Industry Regulatory Authority, Inc. (“FINRA”) Rule 2711 or NYSE Member Rule 472 or any successor or similar rule or regulation. The foregoing provisions of this Section 1.12 shall not apply to the sale of any shares to an underwriter pursuant to an underwriting agreement. The underwriters in connection with any public offering by the Company are intended third party

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beneficiaries of this Section 1.12 and shall have the right, power and authority to enforce the provisions hereof as though they were a party hereto; further, each Holder hereby agrees to enter into written agreement with such underwriters containing terms substantially equivalent to the terms of this Section 1.12, and each Holder hereby agrees that such underwriters shall be entitled to require each such Holder to enter into such a written agreement. Notwithstanding the foregoing, nothing in this Section 1.12 shall prevent a Holder from making a transfer of any Common Stock that was listed on a national stock exchange, actively traded over-the-counter or traded on the NASDAQ Global Market at the time it was acquired by the Holder or was acquired by such Holder pursuant to Rule 144A of the Act, including any shares acquired in any public offering by the Company.

In order to enforce the foregoing covenant, the Company may impose stop-transfer instructions with respect to the Registrable Securities of each Holder (and the shares or securities of every other person subject to the foregoing restriction) until the end of such period.

1.13 Termination of Registration Rights. No Holder shall be entitled to exercise any right provided for in this Section 1 after five (5) years following the consummation of the Initial Public Offering or, as to any Holder, such earlier time at which all Registrable Securities held by such Holder (and any affiliate of the Holder with whom such Holder must aggregate its sales under Rule 144) can be sold in any ninety (90) day period without registration in compliance with Rule 144 of the Act or, as to any Holder, such earlier time at which such Holder holds Registrable Securities constituting less than one percent (1%) of the outstanding voting stock of the Company.

2. Additional Rights.

2.1 Next Equity Financing: Equivalent Rights. In the event that the Company, in connection with its next bona fide equity financing in which the Company issues and sells shares of a series of Preferred Stock other than the Series A, Series A-2 and Series A-2 Preferred Stock (the “Next Equity Financing”), provides investors in the Next Equity Financing with contractual rights (such as registration rights), the Company shall provide substantially equivalent rights to each of the Investors with respect to the Shares (with appropriate adjustment for economic terms or other contractual rights), subject to such Investor’s execution of any agreements, including, if applicable, investors’ rights, co-sale, voting and other agreements, executed by the investors purchasing securities in the Next Equity Financing (such documents referred to herein as the “Next Financing Documents”). Notwithstanding anything herein to the contrary, upon the execution and delivery of the Next Financing Documents by Investors holding a majority of the then outstanding Shares held by all Investors, this Agreement (excluding any then-existing rights or obligations) shall be amended and restated by and into such Next Financing Documents.

2.2 Rights to Future Stock Issuances.

(a) Right of First Offer. Subject to the terms and conditions of this Subsection 2.2 and applicable securities laws, if the Company proposes to offer or sell any New Securities (as defined below), the Company shall first offer such New Securities to each Major Investor (as defined below). A Major Investor shall be entitled to apportion the right of first

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offer hereby granted to it in such proportions as it deems appropriate, among (i) itself and (ii) its Affiliates. The term “Major Investor” means any Investor that, individually or together with such Investor’s Affiliates, holds at least 100,000 shares of Registrable Securities (as adjusted for any stock split, stock dividend, combination, or other recapitalization or reclassification effected after the date hereof). The term “New Securities” means, collectively, equity securities of the Company, whether or not currently authorized, as well as rights, options, or warrants to purchase such equity securities, or securities of any type whatsoever that are, or may become, convertible or exchangeable into or exercisable for such equity securities.

(b) The Company shall give notice (the “Offer Notice”) to each Major Investor, stating (i) its bona fide intention to offer such New Securities, (ii) the number of such New Securities to be offered, and (iii) the price and terms, if any, upon which it proposes to offer such New Securities.

(c) By notification to the Company within twenty (20) days after the Offer Notice is given, each Major Investor may elect to purchase or otherwise acquire, at the price and on the terms specified in the Offer Notice, up to that portion of such New Securities which equals the proportion that the Common Stock then held by such Major Investor (including all shares of Common Stock then issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Preferred Stock and any other Derivative Securities (as defined below) then held by such Major Investor) bears to the total Common Stock of the Company then outstanding (assuming full conversion and/or exercise, as applicable, of all Preferred Stock and other Derivative Securities). The closing of any sale pursuant to this Subsection 2.2 shall occur within the later of ninety (90) days after the date that the Offer Notice is given and the date of initial sale of New Securities pursuant to Subsection 2.2(d). The term “Derivative Securities” means any securities or rights convertible into, or exercisable or exchangeable for (in each case, directly or indirectly), Common Stock, including options and warrants.

(d) If all New Securities referred to in the Offer Notice are not elected to be purchased or acquired as provided in Subsection 2.2(b), the Company may, during the ninety (90 day period following the expiration of the periods provided in Subsection 2.2(b), offer and sell the remaining unsubscribed portion of such New Securities to any Person or Persons at a price not less than, and upon terms no more favorable to the offeree than, those specified in the Offer Notice. If the Company does not enter into an agreement for the sale of the New Securities within such period, or if such agreement is not consummated within sixty (60) days of the execution thereof, the right provided hereunder shall be deemed to be revived and such New Securities shall not be offered unless first reoffered to the Major Investors in accordance with this Subsection 2.2.

(e) The right of first offer in this Subsection 2.2 shall not be applicable to (i) Exempted Securities (as defined in the Company’s Certificate of Incorporation); and (ii) shares of Common Stock issued in the Initial Public Offering.

(f) Termination. The covenants set forth in Subsection 2.2 shall terminate and be of no further force or effect (i) immediately before the consummation of the Initial Public Offering, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon a Deemed Liquidation Event, as such term is defined in the Company’s Certificate of Incorporation, whichever event occurs first.

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2.3 Information Rights.

(a) Delivery of Financial Statements. The Company shall deliver to each Major Investor:

(i) as soon as practicable, but in any event within one hundred twenty (120) days after the end of each fiscal year of the Company (i) a balance sheet as of the end of such year, (ii) statements of income and of cash flows for such year, and (iii) a statement of stockholders’ equity as of the end of such year;

(ii) as soon as practicable, but in any event within forty-five (45) days after the end of each of the first three (3) quarters of each fiscal year of the Company, unaudited statements of income and cash flows for such fiscal quarter, and an unaudited balance sheet and a statement of stockholders’ equity as of the end of such fiscal quarter, all prepared in accordance with GAAP (except that such financial statements may (i) be subject to normal year-end audit adjustments; and (ii) not contain all notes thereto that may be required in accordance with GAAP);

(iii) with respect to the financial statements called for in Subsection 2.3(a) and Subsection 2.3(b), an instrument executed by the chief financial officer and chief executive officer of the Company certifying that such financial statements were prepared in accordance with GAAP consistently applied with prior practice for earlier periods (except as otherwise set forth in Subsection 2.3(b)) and fairly present the financial condition of the Company and its results of operation for the periods specified therein; and

If, for any period, the Company has any subsidiary whose accounts are consolidated with those of the Company, then in respect of such period the financial statements delivered pursuant to the foregoing sections shall be the consolidated and consolidating financial statements of the Company and all such consolidated subsidiaries.

Notwithstanding anything else in this Subsection 2.3 to the contrary, the Company may cease providing the information set forth in this Subsection 2.3 during the period starting with the date sixty (60) days before the Company’s good-faith estimate of the date of filing of a registration statement if it reasonably concludes it must do so to comply with the SEC rules applicable to such registration statement and related offering; provided that the Company’s covenants under this Subsection 2.3 shall be reinstated at such time as the Company is no longer actively employing its commercially reasonable efforts to cause such registration statement to become effective.

(b) Termination of Information Rights. The covenants set forth in Subsection 2.3 shall terminate and be of no further force or effect (i) immediately before the consummation of the Initial Public Offering, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon a Deemed Liquidation Event, as such term is defined in the Company’s Certificate of Incorporation, whichever event occurs first.

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3. Miscellaneous.

3.1 Limitations on Disposition. Each Investor agrees not to make any disposition of any Registrable Securities unless and until the transferee has agreed in writing for the benefit of the Company to be bound by this Agreement, and:

(a) There is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in accordance with such registration statement; or

(b) (i) Such Investor shall have notified the Company of the proposed disposition and shall have furnished the Company with a detailed statement of the circumstances surrounding the proposed disposition, and (ii) if reasonably requested by the Company, such Investor shall have furnished the Company with an opinion of counsel reasonably satisfactory to the Company that such disposition will not require registration of such shares under the Act. It is agreed that the Company will not require opinions of counsel for transactions made pursuant to Rule 144 except in unusual circumstances.

3.2 Successors and Assigns. Except as otherwise provided herein, the terms and conditions of this Agreement shall inure to the benefit of and be binding upon the respective successors and assigns of the parties (including transferees of any shares of Registrable Securities). Nothing in this Agreement, express or implied, is intended to confer upon any party other than the parties hereto or their respective successors and assigns any rights, remedies, obligations, or liabilities under or by reason of this Agreement, except as expressly provided in this Agreement.

3.3 Governing Law; Venue. This Agreement is to be construed in accordance with and governed by the internal laws of the State of Delaware without giving effect to any choice of law rule that would cause the application of the laws of any jurisdiction other than the internal laws of the State of Delaware to the rights and duties of the parties. All disputes and controversies arising out of or in connection with this Agreement shall be resolved exclusively by the state and federal courts located in the State of Delaware and each party hereto agrees to submit to the jurisdiction of said courts and agrees that venue shall lie exclusively with such courts.

3.4 Waiver of Right to Jury Trial. EACH OF INVESTORS, FOUNDERS AND THE COMPANY, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY AS TO ANY ISSUE RELATING HERETO IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS AGREEMENT.

3.5 Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

3.6 Titles and Subtitles. The titles and subtitles used in this Agreement are used for convenience only and are not to be considered in construing or interpreting this Agreement.

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3.7 Delays or Omissions. Except as expressly provided herein, no delay or omission to exercise any right, power or remedy accruing to any party to this Agreement upon any breach or default of any other party under this Agreement shall impair any such right, power or remedy of such non-defaulting party, nor shall it be construed to be a waiver of any such breach or default, or an acquiescence therein, or of or in any similar breach or default thereafter occurring, nor shall any waiver of any single breach or default be deemed a waiver of any other breach or default theretofore or thereafter occurring. Any waiver, permit, consent or approval of any kind or character on the part of any party of any breach or default under this Agreement, or any waiver on the part of any party of any provisions or conditions of this Agreement, must be in writing and shall be effective only to the extent specifically set forth in such writing. All remedies, either under this Agreement or by law or otherwise afforded to any party to this Agreement, shall be cumulative and not alternative.

3.8 Telecopy, Execution and Delivery. A facsimile, telecopy or other reproduction of this Agreement, including a .pdf copy, may be executed by one or more parties and delivered by such party by facsimile or any similar electronic transmission device pursuant to which the signature of or on behalf of such party can be seen. Such execution and delivery shall be considered valid, binding and effective for all purposes. At the request of any party hereto, all parties hereto agree to execute and deliver an original of this Agreement as well as any facsimile, telecopy or other reproduction hereof.

3.9 Further Assurances. Each party hereto agrees to execute and deliver, by the proper exercise of its corporate, limited liability company, partnership or other powers, all such other and additional instruments and documents and do all such other acts and things as may be necessary to more fully effectuate this Agreement.

3.10 Notices. Except as may be otherwise provided herein, all notices, requests, waivers and other communications made pursuant to this Agreement shall be in writing and shall be conclusively deemed to have been duly given (a) when hand delivered to the other party; (b) when sent by electronic mail to the electronic mail address set forth below if sent between 8:00 a.m. and 5:00 p.m. recipient’s local time on a business day, or on the next business day if sent other than between 8:00 a.m. and 5:00 p.m. recipient’s local time on a business day; (c) three business days after deposit in the U.S. mail with first class or certified mail receipt requested postage prepaid and addressed to the other party at the address set forth below; or (d) the next business day after deposit with a national overnight delivery service, postage prepaid, addressed to the parties as set forth below with next business day delivery guaranteed, provided that the sending party receives a confirmation of delivery from the delivery service provider. A party may change or supplement the addresses given above, or designate additional addresses, for purposes of this Section 3.10 by giving the other party written notice of the new address in the manner set forth above.

3.11 Expenses. If any action at law or in equity is necessary to enforce or interpret the terms of this Agreement, the prevailing party shall be entitled to reasonable attorney’s fees, costs and necessary disbursements in addition to any other relief to which such party may be entitled.

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3.12 Amendments and Waivers. Any term of this Agreement may be amended and the observance of any term of this Agreement may be waived (either generally or in a particular instance and either retroactively or prospectively), only with the written consent of the Company and the holders of more than fifty percent (50%) of the Registrable Securities then outstanding. Any amendment or waiver effected in accordance with this paragraph shall be binding upon each holder of any Registrable Securities, each future holder of all such Registrable Securities and the Company. Each Holder acknowledges that by operation of this paragraph, the holders of more than fifty percent (50%) or more of the Registrable Securities will have the right and power to diminish or eliminate all rights of such Holder under this Agreement.

3.13 Severability. If one or more provisions of this Agreement are held to be unenforceable under applicable law, such provision shall be excluded from this Agreement and the balance of the Agreement shall be interpreted as if such provision were so excluded and shall be enforceable in accordance with its terms.

3.14 Aggregation of Stock. All shares of Registrable Securities held or acquired by entities advised by the same investment adviser and affiliated entities or persons under common management or control, including for this purpose Winged Tiger Limited and Puccini Investments Holdings Limited shall be aggregated together for the purpose of determining the availability of any rights under this Agreement.

3.15 Entire Agreement. This Agreement and the documents referred to herein constitute the entire agreement among the parties with respect to the subject matter hereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein or therein.

*         *         *

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IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date first above written.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date and year first written above.

INVESTOR:

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date and year first written above.

SCHEDULE A

SCHEDULE OF INVESTORS

Sun Biopharma (Netherlands) B.V.

Alta Bioequities, L.P.

Anna and Andrew Yaeger

Frank J. Fitzpatrick and Diana A. Fitzpatrick

Anya Joseph Trust

Kiva Joseph Trust

Niall Joseph Trust

SPV Investments, LLC

Rajesh Patil

Krishnan Family Trust dated May 29, 2007

Donna Manning

Raghu Raghuram

Gustav Spangberg Irrevocable 2016 Trust

Eric Spangberg Irrevocable 2016 Trust

Hélène Nathhorst Spångberg

Dino Rossi

SCHEDULE B

SCHEDULE OF FOUNDERS

Krish S. Krishnan

Suma Krishnan