BVF PARTNERS L P/IL - 25 Jan 2024 Form 4 Insider Report for Rain Oncology Inc.

Footnote F1

This Form 4 is filed jointly by Biotechnology Value Fund, L.P. ("BVF"), Biotechnology Value Fund II, L.P. ("BVF2"), Biotechnology Value Trading Fund OS LP ("Trading Fund OS"), BVF Partners OS Ltd. ("Partners OS"), BVF I GP LLC ("BVF GP"), BVF II GP LLC ("BVF2 GP"), BVF GP Holdings LLC ("BVF GPH"), BVF Partners L.P. ("Partners"), BVF Inc. and Mark N. Lampert (collectively, the "Reporting Persons").

Footnote F2

This Form 4 reports securities disposed of pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of December 13, 2023, by and among the Issuer, Pathos AI, Inc., a Delaware corporation ("Parent"), and WK Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Merger Sub"), pursuant to which Merger Sub completed a tender offer for shares of common stock of the Issuer (each, a "Share"). After completion of the tender offer, Merger Sub merged with and into the Issuer (the "Merger"), effective as of January 26, 2024 (the "Effective Time"), with the Issuer continuing as the surviving entity and a wholly owned subsidiary of Parent.

Footnote F3

Securities owned directly by BVF. As the general partner of BVF, BVF GP may be deemed to beneficially own the securities owned directly by BVF. As the sole member of BVF GP, BVF GPH may be deemed to beneficially own securities owned directly by BVF. As the investment manager of BVF, Partners may be deemed to beneficially own the securities owned directly by BVF. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF.

Footnote F4

Securities owned directly by BVF2. As the general partner of BVF2, BVF2 GP may be deemed to beneficially own the securities owned directly by BVF2. As the sole member of BVF2 GP, BVF GPH may be deemed to beneficially own securities owned directly by BVF2. As the investment manager of BVF2, Partners may be deemed to beneficially own the securities owned directly by BVF2. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF2. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF2.

Footnote F5

Securities owned directly by Trading Fund OS. As the general partner of Trading Fund OS, Partners OS may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment manager of Trading Fund OS and the sole member of Partners OS, Partners may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by Trading Fund OS. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by Trading Fund OS.

Footnote F6

The Reporting Persons received the following in exchange for each Share tendered in connection with the Merger: $1.16 in cash per Share and one contingent value right for potential cash payments of up to approximately $0.17 per Share.

Footnote F7

Partners, BVF Inc. and Mr. Lampert may have been deemed to have a pecuniary interest in these options due to a certain agreement between Partners and Gorjan Hrustanovic, who served on the Issuer's board of directors and as a member of Partners, pursuant to which Mr. Hrustanovic was obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of these options to Partners. As such, Mr. Hrustanovic disclaims beneficial ownership of these securities.

Footnote F8

Pursuant to the terms of the Merger Agreement, at the Effective Time, each option to purchase Shares granted under the Issuer's Amended and Restated 2018 Stock Option/Stock Issuance Plan or the Issuer's 2021 Equity Incentive Plan, pursuant to any inducement award or otherwise that was outstanding immediately prior to the Effective Time was cancelled for no consideration.