as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Executive Vice President and Chief Medical Officer — Alison L. Hannah, M.D.: Dr. Alison L. Hannah was promoted to Executive Vice President and Chief Medical Officer.

Completion of Acquisition or Disposition of Assets. As previously disclosed in the Current Report on Form 8-K filed by Rigel Pharmaceuticals, Inc. (the “Company”) on May 12, 2026, the Company entered into a License Agreement (the “License Agreement”) with Arvinas, Inc., Arvinas Operations, Inc., Arvinas Estrogen Receptor, Inc. and Pfizer Inc. (collectively, the “Licensors”), pursuant to which the Licensors granted the Company exclusive, global rights to develop, manufacture and commercialize…

Approval of equity compensation plans and amendments.

Entry into a Material Definitive Agreement. On May 11, 2026, Rigel Pharmaceuticals, Inc. (“Rigel” or the “Company”) entered into a License Agreement (the “Agreement”) with Arvinas, Inc., Arvinas Operations, Inc., Arvinas Estrogen Receptor, Inc. and Pfizer Inc. (collectively, the “Licensors”). Pursuant to the Agreement, the Licensors granted Rigel an exclusive, royalty-bearing license to develop, manufacture and commercialize VEPPANU TM (vepdegestrant) and related products (the “Licensed Produ…

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Termination of a Material Definitive Agreement. On April 16, 2026, Rigel Pharmaceuticals, Inc. (“Rigel”) received written notice from Eli Lilly and Company (“Lilly”) of Lilly’s election to terminate that certain License and Collaboration Agreement, dated February 18, 2021 (the “Agreement”), between Rigel and Lilly. Pursuant to the terms of the Agreement, Lilly has elected to terminate the Agreement in its entirety. The termination will become effective June 15, 2026. The Agreement granted Lil…

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Director — Michael P. Miller: Mr. Michael P. Miller was appointed to the board of directors and will serve on the Compensation Committee.

Results of Operations and Financial Condition. In connection with the press release described in

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Approval of an equity incentive plan amendment.

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Other Events. On March 27, 2025, Rigel Pharmaceuticals, Inc., issued a press release titled “Rigel Announces Settlement Agreement Resolving TAVALISSE® (fostamatinib disodium hexahydrate) Patent Litigation,” a copy of which is attached as Exhibit 99.1 hereto and incorporated herein by reference.

Director — Mark J. Frohlich: Dr. Mark J. Frohlich was appointed to the board of directors and will serve on specific committees.

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Results of Operations and Financial Conditions. In connection with the press release described in

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Director — Dr. Brian Kotzin: Dr. Kotzin resigned from the Board of Directors and related committees.

Entry into a Material Definitive Agreement. On September 3, 2024, Rigel Pharmaceuticals, Inc. (“ Rigel ”) entered into a collaboration and license agreement (the “ License Agreement ”) and a supply agreement (the “ Supply Agreement ”) with Kissei Pharmaceutical Co., Ltd. (“ Kissei ”). Pursuant to the terms of the License Agreement, Kissei received exclusive rights to develop and commercialize olutasidenib in all human diseases in Japan, the Republic of Korea (Korea) and Taiwan (the “ Kissei T…

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…

Material Modification to Rights of Security Holders. The information set forth in

The filing is about the approval of an equity incentive plan amendment, not a management change.

as Exhibit 99.1 hereto. The information in this report, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission ma…