Contract analysis

Section 1.1 — Defined Terms As used in this Agreement, the following terms shall have the meanings set forth below: "Agreement" means this Stockholder Support Agreement, dated as of November 27, 2023, by and among Penterra, Hale, Ridgeline, and Meridian III, as it may be amended, restated, supplemented, or otherwise modified from time to time in accordance with Section 11.3 hereof. "Beneficial Ownership" (and correla

Section 1.2 — Interpretation (a) Except as otherwise expressly provided herein, all capitalized terms used but not defined in this Agreement shall have the meanings ascribed to them in the Merger Agreement. (b) All references in this Agreement to the DGCL shall mean the General Corporation Law of the State of Delaware, as amended, including without limitation Sections 141(a), 144, 228, and 251 thereof. (c) The words

ARTICLE II — REPRESENTATIONS AND WARRANTIES OF DR. MARCUS HALE Dr. Marcus Hale hereby represents and warrants to Penterra as follows:

Section 2.1 — Ownership of Penterra Shares (a) As of the date hereof, Hale is the record and beneficial owner (within the meaning of Rule 13d-3 under the Exchange Act) of 2,140,000 shares of Penterra common stock, par value $0.001 per share (the Hale Penterra Shares), representing approximately 1.8% of the approximately 121,400,000 shares of Penterra common stock issued and outstanding as of the date hereof. The Hale

Section 2.2 — Ownership of Caliston Equity (a) As of the date hereof, Hale is the beneficial owner of a 28.5% equity interest in Caliston (the Hale Caliston Interest), acquired through personal investment of Forty-Two Million Dollars ($42,000,000) across Caliston's Seed, Series A, and Series B funding rounds. The Hale Caliston Interest constitutes all of the equity interests in Caliston beneficially owned by Hale as

Section 2.3 — Authority; Binding Agreement (a) Hale has full legal capacity, right, and authority to execute, deliver, and perform this Agreement and to consummate the transactions contemplated hereby. This Agreement has been duly and validly executed and delivered by Hale. (b) This Agreement constitutes a legal, valid, and binding obligation of Hale, enforceable against Hale in accordance with its terms, subject to

Section 2.4 — No Conflicts The execution, delivery, and performance by Hale of this Agreement, the compliance by Hale with the provisions hereof, and the consummation by Hale of the transactions contemplated hereby do not and will not (a) violate, conflict with, or result in any breach of any provision of any law, statute, rule, regulation, order, writ, injunction, judgment, or decree applicable to Hale, (b) violate,

Section 2.5 — No Proceedings As of the date hereof, no action, suit, investigation, complaint, arbitration, or other proceeding (whether civil, criminal, or administrative) is pending or, to the knowledge of Hale, threatened against Hale before any court, tribunal, arbitral body, governmental agency, or regulatory authority that would reasonably be expected to impair the ability of Hale to perform his obligations und

ARTICLE III — REPRESENTATIONS AND WARRANTIES OF RIDGELINE VENTURES, LP Ridgeline Ventures, LP hereby represents and warrants to Penterra as follows:

Section 3.1 — Organization and Authority (a) Ridgeline is a limited partnership duly organized, validly existing, and in good standing under the laws of the State of Delaware. Ridgeline has full partnership power and authority to execute, deliver, and perform this Agreement and to consummate the transactions contemplated hereby. (b) The execution, delivery, and performance of this Agreement by Ridgeline have been dul

Section 3.2 — Ownership of Caliston Equity (a) As of the date hereof, Ridgeline is the record and beneficial owner of a 22.3% equity interest in Caliston (the Ridgeline Caliston Interest). The Ridgeline Caliston Interest constitutes all of the equity interests in Caliston beneficially owned by Ridgeline (or any of its affiliates) as of the date hereof. (b) Ridgeline served as the lead investor in Caliston's Series C

Section 3.3 — No Conflicts The execution, delivery, and performance by Ridgeline of this Agreement, the compliance by Ridgeline with the provisions hereof, and the consummation by Ridgeline of the transactions contemplated hereby do not and will not (a) violate, conflict with, or result in any breach of any provision of Ridgeline's partnership agreement, certificate of limited partnership, or other organizational doc

Section 3.4 — No Proceedings As of the date hereof, no action, suit, investigation, complaint, arbitration, or other proceeding (whether civil, criminal, or administrative) is pending or, to the knowledge of Ridgeline, threatened against Ridgeline before any court, tribunal, arbitral body, governmental agency, or regulatory authority that would reasonably be expected to impair the ability of Ridgeline to perform its

ARTICLE IV — REPRESENTATIONS AND WARRANTIES OF MERIDIAN LIFE SCIENCES FUND III, LP Meridian Life Sciences Fund III, LP hereby represents and warrants to Penterra as follows:

Section 4.1 — Organization and Authority (a) Meridian III is a limited partnership duly organized, validly existing, and in good standing under the laws of the State of Delaware. Meridian III has full partnership power and authority to execute, deliver, and perform this Agreement and to consummate the transactions contemplated hereby. (b) The execution, delivery, and performance of this Agreement by Meridian III have

Section 4.2 — Ownership of Caliston Equity (a) As of the date hereof, Meridian III is the record and beneficial owner of an 18.7% equity interest in Caliston (the Meridian Caliston Interest). The Meridian Caliston Interest constitutes all of the equity interests in Caliston beneficially owned by Meridian III (or any of its affiliates) as of the date hereof. (b) Meridian III served as the lead investor in Caliston's S

Section 4.3 — No Conflicts The execution, delivery, and performance by Meridian III of this Agreement, the compliance by Meridian III with the provisions hereof, and the consummation by Meridian III of the transactions contemplated hereby do not and will not (a) violate, conflict with, or result in any breach of any provision of Meridian III's partnership agreement, certificate of limited partnership, or other organi

Section 4.4 — No Proceedings As of the date hereof, no action, suit, investigation, complaint, arbitration, or other proceeding (whether civil, criminal, or administrative) is pending or, to the knowledge of Meridian III, threatened against Meridian III before any court, tribunal, arbitral body, governmental agency, or regulatory authority that would reasonably be expected to impair the ability of Meridian III to per

ARTICLE V — COVENANTS OF DR. MARCUS HALE (PENTERRA VOTING OBLIGATIONS)

Section 5.1 — Agreement to Vote Penterra Shares in Favor Hale hereby covenants and agrees that, from and after the date hereof until the Expiration Date, at the Penterra Stockholder Meeting (or any adjournment or postponement thereof), or at any other meeting of the stockholders of Penterra, however called, or in connection with any written consent of the stockholders of Penterra, in each case at which any of the fol

Section 5.2 — Quorum Hale hereby covenants and agrees that, from and after the date hereof until the Expiration Date, at the Penterra Stockholder Meeting (or at any adjournment or postponement thereof), Hale shall be present (in person or by valid proxy) so that all of the Covered Penterra Shares are counted as present for purposes of determining the presence of a quorum at such meeting. In the event that the Penterr

Section 5.3 — No Inconsistent Agreements From and after the date hereof until the Expiration Date, Hale shall not, directly or indirectly, (a) enter into any voting agreement, voting trust, proxy, or similar arrangement or agreement with respect to any of the Covered Penterra Shares that is inconsistent with Hale's obligations pursuant to this Agreement, (b) grant any proxy or power of attorney with respect to any of

Section 5.4 — Acknowledgment of Recusal at Board Level For the avoidance of doubt, the covenants and obligations of Hale under this Article V relate solely to the voting of the Covered Penterra Shares by Hale in his capacity as a stockholder of Penterra and are separate from and in addition to Hale's obligations under the Voting and Recusal Agreement, dated as of June 2, 2023, by and between Penterra and Hale, pursua

ARTICLE VI — COVENANTS OF CALISTON SUPPORTING STOCKHOLDERS (WRITTEN CONSENT OBLIGATIONS)

Section 6.1 — Agreement to Execute Written Consent Each Caliston Supporting Stockholder hereby covenants and agrees that, from and after the date hereof until the Expiration Date, such Caliston Supporting Stockholder shall execute (or cause to be executed) the Written Consent approving and adopting the Merger and the Merger Agreement, and each of the transactions contemplated thereby, with respect to all Caliston Sha

Section 6.2 — Timing of Written Consent Each Caliston Supporting Stockholder covenants and agrees to execute and deliver the Written Consent promptly, and in any event within five (5) business days, following receipt of a written request by Penterra or Caliston to do so, which request may be delivered at any time after the date of the Merger Agreement. Each Caliston Supporting Stockholder acknowledges that the timely

Section 6.3 — No Revocation Each Caliston Supporting Stockholder hereby covenants and agrees that, once executed and delivered, such Caliston Supporting Stockholder shall not revoke, withdraw, modify, or amend the Written Consent or take any action to invalidate or render ineffective the Written Consent, in whole or in part, without the prior written consent of Penterra. Each Caliston Supporting Stockholder acknowled

Section 6.4 — No Inconsistent Agreements From and after the date hereof until the Expiration Date, no Caliston Supporting Stockholder shall, directly or indirectly, (a) enter into any voting agreement, voting trust, proxy, consent, or similar arrangement or agreement with respect to any of such Caliston Supporting Stockholder's Caliston Shares that is inconsistent with such Caliston Supporting Stockholder's obligatio

ARTICLE VII — IRREVOCABLE PROXY

Section 7.1 — Grant of Irrevocable Proxy — Hale (Penterra Shares) (a) Hale hereby irrevocably appoints Penterra (acting through any duly authorized officer of Penterra other than Hale, to avoid any conflict of interest) and any designee of Penterra as Hale's true and lawful attorney-in-fact and proxy (with full power of substitution and resubstitution), for and in the name, place, and stead of Hale, to attend any mee

Section 7.2 — Grant of Irrevocable Proxy — Caliston Supporting Stockholders (Caliston Shares) (a) Each of Hale, Ridgeline, and Meridian III hereby irrevocably appoints Penterra (acting through any duly authorized officer of Penterra other than Hale, to avoid any conflict of interest) and any designee of Penterra as such Caliston Supporting Stockholder's true and lawful attorney-in-fact and proxy (with full power of s

Section 7.3 — Prior Proxies Revoked Each Supporting Stockholder hereby represents that any proxies heretofore given by such Supporting Stockholder with respect to the Covered Penterra Shares (in the case of Hale) or such Supporting Stockholder's Caliston Shares (in the case of each Caliston Supporting Stockholder), as applicable, that are inconsistent with the terms of this Agreement are hereby revoked and that no su

ARTICLE VIII — TRANSFER RESTRICTIONS

Section 8.1 — Restriction on Transfer — Hale Penterra Shares From the date hereof until the Expiration Date, Hale shall not, directly or indirectly: (a) Transfer any Covered Penterra Shares or any interest therein, whether by sale, gift, merger, tendering into any tender offer or exchange offer, or otherwise; (b) deposit any Covered Penterra Shares into a voting trust or enter into any voting agreement, voting arrang

Section 8.2 — Restriction on Transfer — Caliston Shares From the date hereof until the Expiration Date, no Caliston Supporting Stockholder shall, directly or indirectly, (a) Transfer any of its Caliston Shares or any interest therein, whether by sale, gift, merger, or otherwise, (b) deposit any Caliston Shares into a voting trust or enter into any voting agreement, voting arrangement, or pooling agreement with respec

Section 8.3 — Permitted Transfers Notwithstanding the provisions of Sections 8.1 and 8.2, a Supporting Stockholder may Transfer Covered Penterra Shares or Caliston Shares, as applicable, to a Permitted Transferee; provided, however, that: (a) a "Permitted Transferee" means (i) in the case of Hale, an affiliate of Hale (as defined in Rule 12b-2 under the Exchange Act), a family trust for the benefit of Hale or members

Section 8.4 — Transfer of Record; Stop Transfer Instructions Each Supporting Stockholder hereby agrees that Penterra may instruct its transfer agent, Columnar Trust Services, Inc., or any successor transfer agent of Penterra, to (a) place a notation or legend on the certificates or book-entry positions representing the Covered Penterra Shares (in the case of Hale) indicating the existence of this Agreement and the tr

ARTICLE IX — ADDITIONAL COVENANTS

Section 9.1 — No Solicitation From and after the date hereof until the Expiration Date, each Supporting Stockholder shall not, and shall cause its respective affiliates, officers, directors, employees, agents, representatives, and advisors not to, directly or indirectly, (a) solicit, initiate, knowingly encourage, or knowingly facilitate (including by way of furnishing nonpublic information) any inquiry, proposal, in

Section 9.2 — Notification Each Supporting Stockholder shall promptly (and in any event within forty-eight (48) hours) notify Penterra in writing of (a) any approach, inquiry, proposal, indication of interest, or offer from any Person (other than Penterra or Caliston) relating to a Competing Proposal or any matter that could reasonably be expected to lead to a Competing Proposal, including the identity of the Person

Section 9.3 — Further Assurances Each Supporting Stockholder shall, from time to time, execute and deliver, or cause to be executed and delivered, such additional or further consents, documents, instruments, and other assurances, and shall take, or cause to be taken, such further actions, as Penterra or Caliston may reasonably request for the purpose of effectively carrying out the transactions contemplated by this A

Section 9.4 — Waiver of Appraisal Rights To the fullest extent permitted by applicable law, including the DGCL, each Caliston Supporting Stockholder hereby irrevocably and unconditionally waives, and agrees not to assert or perfect, any rights of appraisal, dissenters' rights, or similar rights that such Caliston Supporting Stockholder may have under Section 262 of the DGCL or otherwise with respect to the Merger, th

Section 9.5 — Disclosure Each Supporting Stockholder hereby consents to and authorizes the publication and disclosure by Penterra and Caliston (and their respective affiliates and representatives) of such Supporting Stockholder's identity, the nature of such Supporting Stockholder's commitments, arrangements, and understandings under this Agreement, and the terms of this Agreement, including a copy of this Agreement

Section 10.1 — Expiration Date This Agreement shall automatically terminate, without any notice or other action by any Party, upon the earliest to occur of the following (the date on which this Agreement terminates being the "Expiration Date"): (a) the Effective Time of the Merger (as defined in the Merger Agreement); (b) the valid termination of the Merger Agreement in accordance with its terms, including, without l

Section 10.2 — Effect of Termination Upon termination of this Agreement in accordance with Section 10.1, this Agreement shall thereupon become void and of no further force or effect, all rights and obligations of the Parties hereunder shall terminate, and no Party shall have any liability or obligation to any other Party arising out of or in connection with this Agreement; provided, however, that: (a) the provisions

Section 11.1 — Notices All notices, requests, demands, consents, waivers, and other communications required or permitted hereunder shall be in writing and shall be deemed to have been duly given (a) when delivered personally, (b) when sent by electronic mail (with confirmation of receipt), (c) one (1) business day after being sent by nationally recognized overnight courier service (with proof of delivery), or (d) thr

Section 11.2 — Entire Agreement This Agreement, together with the Merger Agreement, the Voting and Recusal Agreement, and the other agreements, documents, and instruments referred to herein and therein, constitutes the entire agreement among the Parties with respect to the subject matter hereof and supersedes all prior agreements, understandings, representations, and warranties, both written and oral, among the Parti

Section 11.3 — Amendments and Waivers No amendment, modification, supplement, or waiver of any provision of this Agreement shall be effective unless set forth in a written instrument duly executed by each Party to be bound thereby (or, in the case of a waiver, by the Party waiving compliance). No waiver of any provision of this Agreement shall operate or be construed as a waiver of any other provision, and no waiver