Transaction Details

Footnotes

This Form 4 reports securities transacted pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, SANOFI, a French societe anonyme ("Parent"), and Samba Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent ("Purchaser"). | Pursuant to the Merger Agreement, Purchaser completed a tender offer to acquire all of the issued and outstanding shares of common stock of the Issuer, par value $0.001 per share (the "Common Stock"), for $15.50 per share (the "Offer Price"), in cash, without interest and subject to any applicable withholding of taxes. On February 10, 2026, Purchaser merged with and into the Issuer, with the Issuer surviving as an indirect wholly owned subsidiary of Parent (the effective time of such merger, the "Effective Time"). | Pursuant to the terms of the Merger Agreement, at the Effective Time, each share of Common Stock held by the Reporting Person was tendered in exchange for the Offer Price. | Represents performance-based restricted stock units ("PSUs") previously granted to the Reporting Person in 2024, which vest based on how the Issuer's total stockholder return compares to the total stockholder return of an indexed group of companies ("rTSR") over a performance period ending on December 31, 2026. | Pursuant to the terms of the Merger Agreement, at the Effective Time, each PSU award that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash in an amount equal to (i) the number of shares issuable in settlement of such PSU award immediately prior to the Effective Time based on attainment of the performance goal at 150% of the target level, without regard to vesting, multiplied by (ii) the Offer Price, except that in the case of any PSU award that was granted in calendar year 2025, 50% of such cash amount is subject to vesting requirements and scheduled to vest 6 months after the Effective Time, as described in the Merger Agreement. | Represents PSUs previously granted to the Reporting Person in 2025, which vest based on rTSR over a performance period ending on December 31, 2027. | Pursuant to the terms of the Merger Agreement, (i) each stock option that was outstanding as of immediately prior to the Effective Time (other than a stock option granted in calendar year 2025 became fully vested immediately prior to the Effective Time, and (ii) at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time was cancelled and converted into the right to receive cash in an amount equal to (i) the number of shares subject to such stock option immediately prior to the Effective Time, without regard to vesting, multiplied by (ii) the excess of the Offer Price over the exercise price per share of such stock option, except that in the case of any portion of a stock option granted in calendar year 2025 that remained unvested as of the immediately prior to the Effective Time, 50% of such cash amount is subject to vesting requirements and scheduled to vest 6 months after the Effective Time, as described in the Merger Agreement. | The stock option was granted to the Reporting Person in 2025. | The restricted stock units ("RSUs") were granted on February 15, 2024, and were originally scheduled to vest over three years, with 1/3 vesting on each anniversary of February 15, 2024. | Pursuant to the terms of the Merger Agreement, at the Effective Time, each RSU award that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash in an amount equal to (i) the number of shares issuable in settlement of such RSU award immediately prior to the Effective Time without regard to vesting, multiplied by (ii) the Offer Price, except that in the case of any portion of an RSU award granted in calendar year 2025 that remained unvested as of immediately prior to the Effective Time, 50% of such cash amount is subject to vesting requirements and scheduled to vest 6 months after the Effective Time, as described in the Merger Agreement. | The RSUs were granted on February 13, 2025, and were originally scheduled to vest over three years, with 1/3 vesting on each anniversary of February 13, 2025.