OABI

SEC source: 0001846253-23-000016 · edgardoc.xml · nonDerivative · entry 2

Berkman Charles S · CIK 0001392266 · Chief Legal Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 376,105

F1 · shares: Represents shares withheld to satisfy tax withholding obligations upon the vesting of previously reported restricted stock units.

SEC source: 0001846253-23-000016 · edgardoc.xml · nonDerivative · entry 1

Berkman Charles S · CIK 0001392266 · Chief Legal Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 381,509

F1 · shares: Represents shares withheld to satisfy tax withholding obligations upon the vesting of previously reported restricted stock units.

SEC source: 0001846253-23-000010 · edgardoc.xml · derivative · entry 2

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,680

Underlying: Common Stock · 75,680 shares

Expires 2033-01-30

F2 · derivative.exercise_date: The stock option fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000010 · edgardoc.xml · nonDerivative · entry 1

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 94,982

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSU fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000009 · edgardoc.xml · derivative · entry 3

Boyce Sarah · CIK 0001629383 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,840

Underlying: Common Stock · 37,840 shares

Expires 2033-01-30

F2 · derivative.exercise_date: The stock option fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000009 · edgardoc.xml · nonDerivative · entry 1

Boyce Sarah · CIK 0001629383 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 46,190

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSU fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000011 · edgardoc.xml · derivative · entry 2

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 142,020

Underlying: Common Stock · 142,020 shares

Expires 2033-01-30

F2 · derivative.exercise_date: The Stock Option shall vest in three equal annual installments beginning on each anniversary following the Grant Date, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0001846253-23-000011 · edgardoc.xml · nonDerivative · entry 1

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,462,686

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest in three equal annual installments beginning on each anniversary following the Grant Date, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0001846253-23-000012 · edgardoc.xml · derivative · entry 2

Patel Sunil · CIK 0001503062 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,840

Underlying: Common Stock · 37,840 shares

Expires 2033-01-30

F2 · derivative.exercise_date: The stock option fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000012 · edgardoc.xml · nonDerivative · entry 1

Patel Sunil · CIK 0001503062 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 224,265

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSU fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on the first Grant Date Anniversary.

SEC source: 0001846253-23-000087 · primary_doc.xml · nonDerivative · entry 2

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,339,452

F1 · shares: Represents shares withheld to satisfy tax withholding obligations upon the vesting of previously reported restricted stock units ("RSUs").

F2 · balance_after: The Reporting Person previously reported certain awards of Restricted Stock Units (RSUs) in Table I of Form 4, but has elected to report the RSUs in Table II going forward. As a result, the total reported in Column 5 of Table I has been updated to subtract 39,517 RSUs outstanding on June 23, 2023.

SEC source: 0001104659-23-001606 · tm232303-1_4seq1.xml · nonDerivative · entry 1

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 15,871,242

F5 · kind: Represents restricted stock units ("RSUs") granted to Mr. Tamaroff in his capacity as a director of the Issuer, which RSUs vest as to the shares underlying the award in three substantially similar annual installments beginning on November 1, 2023, subject to Mr. Tamaroff's continuing service as a director of the Issuer through the applicable vesting date; provided, that the RSUs shall vest in full (i) in the event of a Change of Control (as defined in the Issuer's 2022 Incentive Award Plan), to the extent Mr. Tamaroff is serving as a director at the time of such transaction, or (ii) in the event that Mr. Tamaroff ceases to serve as a director by reason of death or Permanent Disability (as defined in the Issuer's 2022 Incentive Award Plan).

F5 · shares: Represents restricted stock units ("RSUs") granted to Mr. Tamaroff in his capacity as a director of the Issuer, which RSUs vest as to the shares underlying the award in three substantially similar annual installments beginning on November 1, 2023, subject to Mr. Tamaroff's continuing service as a director of the Issuer through the applicable vesting date; provided, that the RSUs shall vest in full (i) in the event of a Change of Control (as defined in the Issuer's 2022 Incentive Award Plan), to the extent Mr. Tamaroff is serving as a director at the time of such transaction, or (ii) in the event that Mr. Tamaroff ceases to serve as a director by reason of death or Permanent Disability (as defined in the Issuer's 2022 Incentive Award Plan).

F3 · balance_after: In accordance with the letter agreement, dated March 23, 2022, by and among the Issuer, Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), 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. As a result of the liquidation and distribution of all of the assets of the Avista Sponsor to its limited partners, ACP V Onshore and ACP V Offshore (the "Avista Sponsor Liquidating Distribution"),

F4 · balance_after: and pursuant to a Joinder to the Letter Agreement entered into on December 9, 2022 between ACP V Onshore, ACP V Offshore, Avista Sponsor and the Issuer, ACP V Onshore directly holds 595,508 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement, and ACP V Offshore holds 697,791 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement. Additionally, in connection with the Avista Sponsor Liquidating Distribution, each of ACP V Onshore and ACP V Offshore provided to the Issuer an agreement stating that they will each be bound by the transfer restrictions included in the Amended and Restated Registration and Stockholder Rights Agreement, dated as of November 1, 2022, among the Issuer, the Sponsor and the other signatories thereto (the "A&R RSRA") for the duration of the Founder Shares Lock Up Period (as defined in the A&R RSRA).

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), (ii) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), (iii) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore, (iv) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (v) each of Thompson Dean and David Burgstahler, who are the managers of Avista Managing Member (together with ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (vi) Joshua Tamaroff, who is a director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F2 · ownership.nature: ACP V Onshore directly holds 7,283,484 shares of common stock and 5,224,114 warrants. ACP V Offshore directly holds 8,534,450 shares of common stock and 6,121,375 warrants. 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.

F6 · ownership.nature: Mr. Tamaroff is a partner at an affiliate of the Avista Affiliates and has assigned all rights, title and interest in any securities of the Issuer to an affiliate of the Avista Affiliates controlled by Mr. Dean and Mr. Burgstahler. The Avista Affiliates, ACP V Onshore and ACP V Offshore are each "directors by deputization" for the purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Each of the Avista Affiliates and Mr. Tamaroff 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, ACP V Onshore and ACP V Offshore and Mr. Tamaroff disclaims beneficial ownership of the securities issued to Mr. Tamaroff, except to the extent of their pecuniary interest therein, if any.

SEC source: 0000899243-23-001021 · doc4.xml · nonDerivative · entry 1

GUSTAFSON KURT A · CIK 0001462354 · EVP, Finance and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 302,833

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest in three equal annual installments beginning on December 7, 2023, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-23-001017 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,906,125

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest in three equal annual installments beginning on December 7, 2023, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-23-001020 · doc4.xml · nonDerivative · entry 1

Berkman Charles S · CIK 0001392266 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 383,482

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest in three equal annual installments beginning on December 7, 2023, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-23-001022 · doc4.xml · nonDerivative · entry 1

Bertozzi Carolyn R · CIK 0001698766 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,308

F1 · shares: Represents restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest in three equal annual installments beginning on November 11, 2022, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-22-039581 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,826,460

SEC source: 0000899243-22-039582 · doc4.xml · nonDerivative · entry 1

Berkman Charles S · CIK 0001392266 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 336,618

SEC source: 0001846253-23-000087 · primary_doc.xml · nonDerivative · entry 1

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,397,255

F1 · shares: Represents shares withheld to satisfy tax withholding obligations upon the vesting of previously reported restricted stock units ("RSUs").

F2 · balance_after: The Reporting Person previously reported certain awards of Restricted Stock Units (RSUs) in Table I of Form 4, but has elected to report the RSUs in Table II going forward. As a result, the total reported in Column 5 of Table I has been updated to subtract 39,517 RSUs outstanding on June 23, 2023.

SEC source: 0000899243-22-038479 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,838,084

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.48 to $3.87. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · derivative · entry 7

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 6,121,375

Underlying: Common stock, par value $0.0001 · 6,121,375 shares

Expires 2027-11-01

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F9 · shares: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · shares: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · price: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · price: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · derivative.exercise_date: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · derivative.exercise_date: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F5 · ownership.nature: Directly owned by ACP V Offshore. 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.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · derivative · entry 6

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 5,224,114

Underlying: Common stock, par value $0.0001 · 5,224,114 shares

Expires 2027-11-01

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F9 · shares: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · shares: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · price: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · price: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · derivative.exercise_date: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · derivative.exercise_date: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F4 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · derivative · entry 5

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 0

Underlying: Common stock, par value $0.0001 · 11,345,489 shares

Expires 2027-11-01

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F9 · shares: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · shares: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · price: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · price: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F9 · derivative.exercise_date: 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 became exercisable (including by cash settlement) on December 1., 2022.

F10 · derivative.exercise_date: In connection with the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and OmniAb, Inc.(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 became exercisable (including by cash settlement) December 31, 2022.

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · nonDerivative · entry 3

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 8,534,450

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F3 · price: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F6 · balance_after: In accordance with the letter agreement, dated March 23, 2022, among the Issuer, Avista Sponsor, Legacy OmniAb 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. As a result of the transactions described in this Form 4, and pursuant to a Joinder to the Letter Agreement entered into on December 9, 2022 between ACP V Onshore, ACP V Offshore, Avista Sponsor and the Issuer, ACP V Onshore directly holds 595,508 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement, and ACP V Offshore holds 697,791 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement.

F7 · balance_after: Additionally, in connection with the transactions described in this Form 4, each of ACP V Onshore and ACP V Offshore provided to the Issuer an agreement stating that they will each be bound by the transfer restrictions included in the Amended and Restated Registration and Stockholder Rights Agreement, dated as of November 1, 2022, among the Issuer, the Sponsor and the other signatories thereto (the "A&R RSRA") for the duration of the Founder Shares Lock Up Period (as defined in the A&R RSRA).

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F5 · ownership.nature: Directly owned by ACP V Offshore. 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.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · nonDerivative · entry 2

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 7,283,484

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F3 · price: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F6 · balance_after: In accordance with the letter agreement, dated March 23, 2022, among the Issuer, Avista Sponsor, Legacy OmniAb 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. As a result of the transactions described in this Form 4, and pursuant to a Joinder to the Letter Agreement entered into on December 9, 2022 between ACP V Onshore, ACP V Offshore, Avista Sponsor and the Issuer, ACP V Onshore directly holds 595,508 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement, and ACP V Offshore holds 697,791 of the shares of common stock subject to forfeiture pursuant to the terms of the Letter Agreement.

F7 · balance_after: Additionally, in connection with the transactions described in this Form 4, each of ACP V Onshore and ACP V Offshore provided to the Issuer an agreement stating that they will each be bound by the transfer restrictions included in the Amended and Restated Registration and Stockholder Rights Agreement, dated as of November 1, 2022, among the Issuer, the Sponsor and the other signatories thereto (the "A&R RSRA") for the duration of the Founder Shares Lock Up Period (as defined in the A&R RSRA).

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F4 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

SEC source: 0001104659-22-126643 · tm2232531-1_4seq1.xml · nonDerivative · entry 1

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Avista Capital Partners V, L.P. · CIK 0001774142 · Director · 10% owner

Avista Capital Partners (Offshore) V, L.P. · CIK 0001774143 · Director · 10% owner

Avista Capital Partners V GP, L.P. · CIK 0001957305 · Director · 10% owner

Avista Capital Managing Member V, LLC · CIK 0001957307 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 0

F3 · shares: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F3 · price: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

F1 · ownership.nature: This form is being filed by each of the following Reporting Persons: (i) Avista Acquisition LP II, a Cayman Islands limited partnership ("Avista Sponsor"), (ii) Avista Acquisition GP LLC II, a Cayman Islands limited liability company ("Avista Sponsor GP"), which is the general partner of Avista Sponsor, (iii) Avista Capital Partners V, L.P., a Delaware limited partnership ("ACP V Onshore"), which is a limited partner of Avista Sponsor, (iv) Avista Capital Partners (Offshore) V, L.P., a Bermuda limited partnership ("ACP V Offshore"), which is a limited partner of Avista Sponsor, (v) Avista Capital Partners V GP, L.P., a Delaware limited partnership ("ACP V GP"), which is the general partner of ACP V Onshore and ACP V Offshore,

F2 · ownership.nature: (vi) Avista Capital Managing Member V, LLC, a Delaware limited liability company ("Avista Managing Member"), which is the general partner of ACP V VP, (vii) each of Thompson Dean and David Burgstahler, who are the managers of Avista Sponsor GP and Avista Managing Member (together with ACP V Onshore, ACP V Offshore, ACP V GP and Avista Managing Member, the "Avista Affiliates"), and (viii) Joshua Tamaroff, who is a Director of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer").

F3 · ownership.nature: Each of the transactions described in this Form 4 are being made in connection with the liquidation and dissolution of Avista Sponsor and Avista Sponsor GP. In connection with its liquidation, Avista Sponsor distributed all of its assets, consisting solely of securities of the Issuer, pro rata for no consideration to its limited partners, ACP V Onshore and ACP V Offshore. As a result of these transactions and their subsequent dissolution, Avista Sponsor and Avista Sponsor GP will no longer hold, directly or indirectly, any securities in the Issuer.

SEC source: 0000899243-22-038124 · doc4.xml · derivative · entry 1

GUSTAFSON KURT A · CIK 0001462354 · EVP, Finance and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 697,520

Underlying: Common Stock · 697,520 shares

Expires 2032-12-07

F1 · derivative.exercise_date: The stock option vests and is exercisable as to 12.5% of the underlying shares on June 7, 2023, and in 42 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-22-038123 · doc4.xml · derivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 298,311

Underlying: Common Stock · 298,311 shares

Expires 2032-12-07

F1 · derivative.exercise_date: The stock option vests and is exercisable as to 12.5% of the underlying shares on June 7, 2023, and in 42 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-22-038122 · doc4.xml · derivative · entry 1

Berkman Charles S · CIK 0001392266 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 175,477

Underlying: Common Stock · 175,477 shares

Expires 2032-12-07

F1 · derivative.exercise_date: The stock option vests and is exercisable as to 12.5% of the underlying shares on June 7, 2023, and in 42 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service to the Issuer through each such vesting date.

SEC source: 0000899243-22-038003 · doc4.xml · nonDerivative · entry 1

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 77,476

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.55 to $3.835. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0000899243-22-037741 · doc4.xml · derivative · entry 2

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Tamaroff Joshua Alexander · CIK 0001705548 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 161,849

Underlying: Common Stock · 161,849 shares

Expires 2032-12-01

F3 · shares: 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.

F3 · derivative.exercise_date: 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.

F1 · ownership.nature: 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").

F3 · ownership.nature: 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.

SEC source: 0000899243-22-037742 · doc4.xml · nonDerivative · entry 1

GUSTAFSON KURT A · CIK 0001462354 · EVP, Finance and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 163,329

SEC source: 0000899243-22-037740 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,688,084

SEC source: 0000899243-22-037744 · doc4.xml · nonDerivative · entry 1

Berkman Charles S · CIK 0001392266 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 343,136

SEC source: 0000899243-22-037736 · doc4.xml · derivative · entry 1

Bertozzi Carolyn R · CIK 0001698766 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 161,849

Underlying: Common Stock · 161,849 shares

Expires 2032-12-01

F1 · derivative.exercise_date: The stock option vests in three substantially similar annual installments beginning on November 1, 2023.

SEC source: 0000899243-23-001023 · doc4a.xml · derivative · entry 1

Bertozzi Carolyn R · CIK 0001698766 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 200,000

Underlying: Common Stock · 200,000 shares

Expires 2032-12-01

F1 · shares: Represents a stock option granted on December 1, 2022 to the reporting person in her position as a Director of the Issuer, which vests in three substantially similar annual installments beginning on November 1, 2023.

F2 · shares: This amendment is being filed to correct the Form 4 filed on December 5, 2022, which inadvertently understated the amount of shares awarded to the reporting person on December 1, 2022.

F1 · derivative.exercise_date: Represents a stock option granted on December 1, 2022 to the reporting person in her position as a Director of the Issuer, which vests in three substantially similar annual installments beginning on November 1, 2023.

SEC source: 0000899243-22-037303 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,705,350

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.9275 to $3.57. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0000899243-22-037153 · doc4.xml · nonDerivative · entry 1

GUSTAFSON KURT A · CIK 0001462354 · EVP, Finance and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 170,062

SEC source: 0000899243-22-035694 · doc4.xml · nonDerivative · entry 1

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,226

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.99 to $3.15. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0000899243-22-035698 · doc4.xml · nonDerivative · entry 2

Boyce Sarah · CIK 0001629383 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By spouse

Disclosed balance after: 36,000

SEC source: 0000899243-22-035469 · doc4.xml · nonDerivative · entry 1

FOEHR MATTHEW W · CIK 0001237556 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,405,350

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.6275 to $2.85. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0000899243-22-035565 · doc4.xml · nonDerivative · entry 1

Patel Sunil · CIK 0001503062 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 215,512

SEC source: 0000899243-22-035698 · doc4.xml · nonDerivative · entry 1

Boyce Sarah · CIK 0001629383 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By spouse

Disclosed balance after: 21,000

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.71 to $2.79. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0000899243-22-035061 · doc4.xml · derivative · entry 13

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 246,648 shares

Expires 2023-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_date: The stock option is fully vested and exercisable.

SEC source: 0000899243-22-035061 · doc4.xml · nonDerivative · entry 2

HIGGINS JOHN L · CIK 0001208906 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,423,169

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001104659-22-114525 · tm2229290-1_4seq1.xml · derivative · entry 2

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 11,345,489

Underlying: Common stock, par value $0.0001 · 11,345,489 shares

Expires 2027-11-01

F5 · shares: 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.

F6 · shares: 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.

F5 · price: 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.

F6 · price: 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.

F5 · derivative.exercise_date: 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.

F6 · derivative.exercise_date: 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.

F1 · ownership.nature: 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, and Thompson Dean and David Burgstahler, who are the managers of Avista GP. Because of the relationships among the Reporting Persons, the Reporting Persons may be deemed to beneficially own the securities reported herein to the extent of their respective pecuniary interests. Each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein, if any.

F2 · ownership.nature: Directly owned by Avista Sponsor.

SEC source: 0001104659-22-114525 · tm2229290-1_4seq1.xml · nonDerivative · entry 1

Avista Acquisition GP LLC II · CIK 0001846167 · Director · 10% owner

Burgstahler David F · CIK 0001374179 · Director · 10% owner

Dean Thompson · CIK 0001069096 · Director · 10% owner

Avista Acquisition LP II · CIK 0001846254 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Notes

Disclosed balance after: 15,817,934

F3 · shares: Avista Sponsor acquired the shares of common stock of OmniAb, Inc. (f/k/a Avista Public Acquisition Corp. II) (the "Issuer") in accordance with the Agreement and Plan of Merger, dated as of March 23, 2022 (the "Merger Agreement"), by and among the Issuer, Ligand Pharmaceuticals Incorporated, OmniAb, Inc. ("Legacy OmbiAb"), and Orwell Merger Sub Inc. and the Amended and Restated Forward Purchase Agreement, dated March 23, 2022, by and among the Issuer, Avista Sponsor and Legacy OmniAb (the "A&R Forward Purchase Agreement").

F4 · balance_after: In accordance with the letter agreement, dated March 23, 2022, among the Issuer, Avista Sponsor, Legacy OmniAb 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.

F1 · ownership.nature: 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, and Thompson Dean and David Burgstahler, who are the managers of Avista GP. Because of the relationships among the Reporting Persons, the Reporting Persons may be deemed to beneficially own the securities reported herein to the extent of their respective pecuniary interests. Each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein, if any.

F2 · ownership.nature: Directly owned by Avista Sponsor.

SEC source: 0000899243-22-035066 · doc4.xml · derivative · entry 3

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,840

Underlying: Common Stock · 37,840 shares

Expires 2032-06-10

F1 · kind: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.

F1 · price: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.

F5 · derivative.exercise_date: The stock option fully vests on the earlier of (i) the date of the next annual meeting of the Issuer's stockholders or (ii) on June 10, 2023.

SEC source: 0000899243-22-035066 · doc4.xml · derivative · entry 2

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,298

Underlying: Common Stock · 19,298 shares

Expires 2031-07-12

F1 · kind: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.

F1 · price: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.

F4 · derivative.exercise_date: The stock option vests and is exercisable in three substantially equal annual installments beginning on July 12, 2022.

SEC source: 0000899243-22-035066 · doc4.xml · nonDerivative · entry 1

Cochran Jennifer R. · CIK 0001872349 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,226

F1 · kind: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.

F2 · shares: Includes 12,545 restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock and does not expire.

F3 · shares: Includes 10,784 earn-out shares subject to forfeiture provisions described in the Merger Agreement.

F1 · price: Pursuant to the business combination of Avista Public Acquisition Corp. II and OmniAb, Inc. ("Legacy OmniAb"), as contemplated by an agreement and plan of merger, dated March 23, 2022 (the "Merger Agreement"), each share of common stock, option and award of restricted stock unit of Legacy OmniAb automatically converted into the right to receive securities of the Issuer with the same terms and conditions in accordance with an exchange ratio described in the Merger Agreement.