Item 4 of the Schedule 13D is hereby amended to incorporate the following at the end thereof: On August 4, 2025, the Issuer, XOMA Royalty Corporation ("Purchaser") and XRA 4 Corp., a wholly owned subsidiary of Purchaser ("Merger Sub") entered into an Agreement and Plan of Merger (the "Merger Agreement"). Pursuant to the Merger Agreement, upon the terms and subject to the conditions thereof, Purchaser commenced a tender offer (the "Offer") to acquire all of the outstanding shares of Common Stock of the Issuer (the "Shares"), at an offer price of (i) $1.95 in cash, without interest, plus (ii) one non-transferable contractual contingent value right per Share (collectively, the "Offer Price"). The Offer expired at the end of the day, one minute after 11:59 p.m. Eastern Time, on September 15, 2025. On September 17, 2025, Purchaser accepted for purchase all shares of Common Stock that were validly tendered and not validly withdrawn in accordance with the terms of the Offer, which included the Shares that were held by the Reporting Persons. On September 17, 2025, upon the terms and subject to the conditions set forth in the Merger Agreement and in accordance with Section 251(h) of the Delaware General Corporation Law, Merger Sub merged with and into the Issuer, with the Issuer surviving as a wholly owned subsidiary of Purchaser (the "Merger"), without a meeting or vote of stockholders of the Issuer (the "Effective Time"). At the Effective Time, the Shares held by the Reporting Persons were each converted into the right to receive the Offer Price. In addition, pursuant to the Merger Agreement, at the Effective Time, each outstanding stock option, whether vested or unvested, that had an exercise price per Share that was greater than the Offer Price was canceled for no consideration. This included the stock options held by Heron.