X0306 4 2022-12-01 0 0001846253 OmniAb, Inc. OABI 0001846167 Avista Acquisition GP LLC II 65 EAST 55TH STREET 18TH FLOOR NEW YORK NY 10022 1 0 1 0 0001374179 Burgstahler David F 65 EAST 55TH STREET 18TH FLOOR NEW YORK NY 10022 1 0 1 0 0001069096 Dean Thompson 65 EAST 55TH STREET 18TH FLOOR NEW YORK NY 10022 1 0 1 0 0001846254 Avista Acquisition LP II 65 EAST 55TH STREET 18TH FLOOR NEW YORK NY 10022 1 0 1 0 0001705548 Tamaroff Joshua Alexander 65 EAST 55TH STREET 18TH FLOOR NEW YORK NY 10022 1 0 1 0 Common stock, par value $0.0001 per share 15817934 I See Notes Stock Option 3.35 2022-12-01 4 A 0 161849 0.00 A 2032-12-01 Common Stock 161849 161849 I See Notes Warrants 11.50 2027-11-01 Common Stock 11345489 11345489 I See Notes This form is being filed by each of the following Reporting Persons: Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista GP"), which is the general partner of Avista Sponsor, and Thompson Dean and David Burgstahler, who are the managers of Avista GP (together with Avista Sponsor and Avista GP, the "Avista Affiliates"), and Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer"). Directly owned by Avista Sponsor. Each of the Avista Affiliates may be deemed to beneficially own the securities reported on this line item to the extent of their respective pecuniary interests. Each of the Avista Affiliates disclaims beneficial ownership of the securities reported on this line item, except to the extent of their pecuniary interest therein, if any. Represents a stock option granted on December 1, 2022 to Joshua Tamaroff in his position as a Director of the Issuer, which vests in three substantially similar annual installments beginning on November 1, 2023. Mr. Tamaroff is a partner at Avista Capital Partners and has assigned all rights, title and interest in the stock option to the Avista Affiliates. The Avista Affiliates are each "directors by deputization" for the purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Each of the Reporting Persons may be deemed to beneficially own the securities reported on this line item to the extent of their respective pecuniary interests. Each of the Reporting Persons disclaims beneficial ownership of the securities reported on this line item, except to the extent of their pecuniary interest therein, if any. In accordance with the letter agreement, dated March 23, 2022, among the Issuer, Avista Sponsor, OmniAb Operations, Inc. (f/k/a OmniAb, Inc.) and other parties (the "Letter Agreement"), if the Triggering Event (as defined in the Letter Agreement) has not occurred during the Earnout Period (as defined in the Letter Agreement), 1,293,299 shares of common stock will be automatically forfeited to the Issuer for no consideration. In connection with the completion of the Issuer's August 2021 initial public offering, Avista Sponsor purchased 8,233,333 warrants in a private placement from the Issuer, each exercisable to purchase (subject, initially, to the satisfaction of certain material conditions) one Class A ordinary share, par value $0.0001 per share, of the Issuer for $11.50 per share. The material conditions to exercise were satisfied upon the closing of the transactions contemplated by the Merger Agreement (the "Closing"), and the warrants by their terms become exercisable (including by cash settlement) 30 days following the Closing. In connection with the A&R Forward Purchase Agreement, Avista Sponsor purchased an aggregate 3,112,156 warrants in private placements from the Issuer, each exercisable to purchase (subject, initially, to the satisfaction of certain material conditions) one share of common stock, par value $0.0001 per share, of the Issuer for $11.50 per share. The material conditions to exercise were satisfied on the Closing, and the warrants by their terms become exercisable (including by cash settlement) 30 days following the Closing. See Exhibit 99.1 2022-12-05