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Shareholder Proposal No. 1 — The Business Combination Proposal — a proposal to approve by special resolution and adopt (i) the Agreement and Plan of Merger, dated as of March 23, 2022 (the “Merg- er Agreement”), by and among APAC, Ligand Pharmaceuticals Incorporated, a Delaware corporation (“Ligand”), OmniAb, Inc., a Delaware corporation and wholly-owned subsidiary of Ligand (“OmniAb”), and Orwell Merger Sub Inc., a Delaware corporation and wholly-owned subsidiary of APAC, (ii) the Transaction Documents (as defined in the Merger Agreement) and (iii) each of the trans- actions contemplated thereby, in each case, in accordance with the terms and subject to the conditions set forth in the Merger Agreement and such Transaction Documents, as more fully described elsewhere in the accompanying proxy state- ment/prospectus/information statement (the “Business Combination Proposal”). Proposal No. 2 — The Domestication Proposal — a proposal to approve by special resolution the change of APAC’s jurisdiction of incorporation (the “Domestica- tion”), by deregistering as an exempted company in the Cayman Islands and continuing and domesticating under the name “OmniAb, Inc.” as a corporation incorporated under the laws of the State of Delaware (the “Domestication Proposal”). Proposal No. 3 — The Organizational Documents Proposal — a proposal to approve by special resolution and adopt the proposed new certificate of incorporation (the “Proposed Certificate of Incorporation”) and the pro- posed new bylaws (the “Proposed Bylaws”) of APAC after giving effect to the Domestication (“New OmniAb”) (the “Organizational Documents Proposal”). Proposal No. 4 — The Non-Binding Governance Proposals — a proposal to approve a non-binding advisory basis, certain material differences between APAC’s Amended and Restated Memorandum and Articles of Association (as it may be amended from time to time, the “Cayman Constitutional Documents”) and the Proposed Certificate of Incorporation and Proposed Bylaws, presented separately in accordance with the United States Securities and Exchange Com- mission requirements (collectively, the “Non-Binding Governance Proposals”). 4a. Change the Authorized Capital Stock – To approve and adopt provisions in the Proposed Cer- tificate of Incorporation to authorize the change in the authorized capital stock of APAC from (i) 500,000,000 APAC Class A Ordinary Shares, 50,000,000 APAC Class B Ordinary Shares and 5,000,000 preference shares, par value $0.0001 per share, of APAC to (ii) 1,000,000,000 shares of New OmniAb common stock and 100,000,000 shares of New OmniAb preferred stock. 4b. Change the Stockholder Vote Required to Amend the Certificate of Incorporation – To approve and adopt provisions in the Proposed Cer- tificate of Incorporation to require that the affirmative vote of holders of at least 66 2/3% of the voting power of all then-outstanding New OmniAb Common Stock entitled to vote generally in the election of direc- tors, voting together as a single class, to adopt, amend or repeal the Proposed Bylaws and the provisions in the Proposed Certificate of Incorporation related to preferred stock, the board of directors, stockholders, limitation on liability and indemnification of directors, forum selection and amendments to the Pro- posed Certificate. 4c. Establish a Classified Board of Directors – To approve and adopt provisions in the Proposed Cer- tificate of Incorporation to would divide the New Om- niAb Board of directors into three classes, with only one class of directors being elected in each year and each class serving a three-year term. 4d. Action by Written Consent Stockholders – To approve and adopt provisions in the Proposed Certificate of Incorporation to provide that any action required or permitted to be taken by the New OmniAb Stockholders may be effected at a duly called annual or special meeting of such stockholders, and may not be taken by written consent. 4e. Removal of Directors – To approve and adopt provisions in the Proposed Certificate of Incorporation to require the affirmative vote of the holders of at least 66 2/3% of the voting power of the outstanding shares of New OmniAb entitled to vote to remove a director for cause. 4f. Delaware as Exclusive Forum – To approve and adopt provisions in the Proposed Certificate of Incorporation to provide that, unless New OmniAb consents in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall be the sole and ex- clusive forum for the types of actions or proceedings under Delaware statutory or common law for the actions described in the proxy statement/prospectus/ information statement. 5. Proposal No. 5 — The Stock Issuance Proposal — a proposal to approve by ordinary resolution, for the purposes of complying with the applicable provisions of Nasdaq Rule 5635, the issuance of shares of common stock, par value $0.0001, of New OmniAb pursuant to (a) the Domestication, (b) the PIPE Investment, (c) the Redemption Backstop and (d) the Merger, as each of the capitalized terms used in clauses (b), (c) and (d) are defined in the Merger Agreement and described in the accompanying proxy statement/prospectus/in- formation statement (the “Stock Issuance Proposal”). 6. Proposal No. 6 — The Incentive Plan Proposal — a proposal to approve by ordinary resolution, the Omni- Ab, Inc. 2022 Incentive Award Plan (the “Incentive Plan Proposal”) 7. Proposal No. 7 — The ESPP Proposal — a proposal to approve by ordinary resolution, the OmniAb, Inc. 2022 Employee Stock Purchase Plan (the “ESPP Proposal”). Proposal No. 8 — The Director Election Proposal — a proposal to elect seven directors to serve staggered terms on the New OmniAb Board upon the con- summation of the Business Combination until the first, second and third annual meeting of stockholders following the date of effectiveness of the Proposed Cer- tificate of Incorporation, as applicable, or until the election and qualification of their respective successors in office, subject to their earlier death, resignation or removal (the “Director Election Proposal”). Class I Nominees: 8a. Matthew W. Foehr 8b. Jennifer Cochran Class II Nominees: 8c. Sarah Boyce 8d. Sunil Patel Class III Nominees: 8e. John L. Higgins 8f. Carolyn Bertozzi 8g. Joshua Tamaroff 9. Proposal No. 9 — The Adjournment Proposal — to consider and vote upon a proposal to approve the ad- journment of the extraordinary general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient shares represented to constitute a quorum necessary to conduct business at the extraordinary general meeting or for the approval of one or more proposals at the extraordinary general meeting or to the extent necessary to ensure that any required supplement or amendment to the accompanying proxy statement/prospectus/information state- ment is provided to APAC shareholders (the “Adjournment Proposal”). 20140 Avista Public Acquisition Corp. II Proxy Card Rev2 Back Signature______________________________Signature, if held jointly__________________________________Date_____________, 2022 Note: Please sign exactly as name appears hereon. When shares are held by joint owners, both should sign. When signing as attorney, executor, administrator, trustee, guardian, or corporate officer, please give title as such. CONTROL NUMBER PROXY CARD THE BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” PROPOSALS 1 THROUGH 9. Please mark your votes like this X FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN Important Notice Regarding the Internet Availability of Proxy Materials for the extraordinary general meeting of Avista Public Acquisition Corp. II FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN FOR AGAINST ABSTAIN