On May 27, 2020, Gilead and the Issuer entered into an Option, License and Collaboration Agreement (the "Collaboration Agreement") pursuant to with Gilead obtained an exclusive option to acquire an exclusive license to all of the Issuer's current and future clinical programs during the 10-year collaboration term and, for those programs that enter clinical development prior to the end of the collaboration term, for up to an additional three years thereafter. In addition to the Collaboration Agreement, Gilead and the Issuer entered into a Common Stock Purchase Agreement (the "Purchase Agreement"), which was amended and restated on January 31, 2021 to account for the Second Purchase (the "Amended and Restated Purchase Agreement"), on June 27, 2023 to account for the Third Purchase (the "Second Amended and Restated Purchase Agreement"), and on January 29, 2024 to account for the Fourth Purchase (the "Third Amended and Restated Purchase Agreement") and an Investor Rights Agreement (as amended by Amendment No. 1 thereto, which was subsequently amended and restated on January 29, 2024, the "Amended and Restated Investor Rights Agreement" and, together with the Third Amended and Restated Purchase Agreement, the "Equity Agreements") pursuant to which Gilead made the Initial Purchase at the Initial Purchase Price, the Second Purchase at the Second Purchase Price, the Third Purchase at the Third Purchase Price and the Fourth Purchase at the Fourth Purchase Price. Gilead also has the right, at its option, to purchase additional shares from the Issuer, up to a maximum of 35% of the Issuer's then-outstanding Common Stock, from time to time for a period of five years from the closing of the Initial Purchase, at a purchase price equal to the greater of a 20% premium to market (based on a trailing five-day average closing price) at the time Gilead exercises such option and the Initial Purchase Price. The Equity Agreements also include standstill and lock-up provisions and provide Gilead with certain other stock purchase and registration rights, as well as the right to designate three individuals to be appointed to the Issuer's board of directors. In connection with the Public Offering, Gilead entered into a customary lock-up agreement (the "Lock-Up Agreement") with the representatives of the underwriters. The Lock-Up Agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference. The acquisitions by the Reporting Person of the Issuer's securities as described herein were effected in connection with entry into the Collaboration Agreement and the Equity Agreements, and because of the belief that the securities of the Issuer represent an attractive investment. The foregoing description of the Equity Agreements is not complete and is subject to and qualified in its entirety by reference to the full text of such agreements. The Third Amended and Restated Purchase Agreement and the Amended and Restated Investor Rights Agreement were filed previously as Exhibits 99.1 and 99.2, respectively, to the Amendment No. 3 to Schedule 13D filed by the Reporting Person with the SEC on January 31, 2024. Except as otherwise described herein, the Reporting Person currently has no plan(s) or proposal(s) that relate to, or would result in, any of the events or transactions described in Item 4(a) through (j) of Schedule 13D, although the Reporting Person reserves the right, at any time and from time to time, to review or reconsider such position and/or change such purpose and/or formulate plans or proposals with respect thereto. The Reporting Person intends to review from time to time its investment in the Issuer and the Issuer's business affairs, financial position, performance and other investments considerations. The Reporting Person may from time to time engage in discussions with the Issuer, its directors and officers, other stockholders of the Issuer and other persons on matters that relate to the management, operations, business, assets, capitalization, financial condition, strategic plans, governance and the future of the Issuer and/or its subsidiaries. Based upon such review and discussions, as well as general economic, market and industry conditions and prospects and the Reporting Person's liquidity requirements and investment considerations, and subject to the limitations in the agreements described above, the Reporting Person may consider additional courses of action, which may include, in the future, formulating plans or proposals regarding the Issuer and/or its subsidiaries, including possible future plans or proposals concerning events or transactions of the kind described in Item 4(a) through (j) of Schedule 13D.