Material Modification to Rights of Security Holders. The disclosures under the Introductory Note, Item 3.01,

Completion of Acquisition or Disposition of Assets. The disclosures under the Introductory Note, Item 3.01, Item 3.03, Item 5.01,

Changes in Control of Registrant. The disclosures under the Introductory Note, Item 3.01, Item 3.03,

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. The disclosures under the Introductory Note are incorporated herein by reference. On July 15, 2026, the Company (i) notified the Nasdaq Capital Market (“ Nasdaq ”) of the consummation of the Merger and its intent to remove all Company Common Stock from Nasdaq and (ii) requested that Nasdaq (A) maintain the halt in trading of Company Common Stock, which was effective following the closing of af…

Director — Patrick J. McEnany, Richard J. Daly, Daniel J. Curran, M.D., Donald A. Denkhaus, Molly Harper, Tamar Thompson, David S. Tierney, M.D.: All previous directors resigned in connection with the Merger.

Other Events. As previously announced, on May 6, 2026, Catalyst Pharmaceuticals, Inc. (“ Catalyst ”) entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) with Angelini Pharma S.p.A., an Italian Società per azioni (“ Angelini Pharma ”), and Angelini Cielo Inc., a Delaware corporation and wholly-owned subsidiary of Angelini Pharma (“ Merger Sub ”), providing for the merger of Merger Sub with and into Catalyst (the “ Merger ”), with Catalyst surviving the Merger as a wholly-ow…

Other Events On May 7, 2026, the Company issued a press release announcing that it and its licensor, SERB S.A. (“ SERB ”) have entered into a settlement agreement (“ Settlement Agreement ”) with Hetero USA, Inc. (“ Hetero ”). This Settlement Agreement resolves the patent litigation brought by the Company and SERB in response to Hetero’s Abbreviated New Drug Application (“ ANDA ”) seeking approval to market a generic version of FIRDAPSE ® (amifampridine) 10 mg tablets prior to expiration of th…

Entry into a Material Definitive Agreement On May 6, 2026, Catalyst Pharmaceuticals, Inc. (“ Catalyst ” or the “ Company ”) entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) with Angelini Pharma S.p.A., an Italian Società per azioni (“ Angelini Pharma ” or “ Parent ”), and Angelini Cielo Inc., a Delaware corporation and wholly-owned subsidiary of Parent (“ Merger Sub ”), providing for the merger of Merger Sub with and into the Company (the “ Merger ”), with the Company s…

Other Events On October 1, 2025, the Company issued a press release announcing that its Board of Directors has approved a share repurchase program authorizing the Company to repurchase up to $200 million of its common stock between October 1, 2025 and December 31, 2026. Repurchases under the new share repurchase program may be made through a variety of methods, including open market or privately negotiated purchases. The timing and amount of shares repurchased will depend on the stock price,…

Other Events On August 25, 2025, the Company issued a press release announcing that it and its licensor, SERB S.A. (“SERB”) have entered into a settlement agreement (“Agreement”) with Lupin Ltd. and Lupin Pharmaceuticals, Inc. (collectively, “Lupin”). This Agreement resolves the patent litigation brought by the Company and SERB in response to Lupin’s Abbreviated New Drug Application (“ANDA”) seeking approval to market a generic version of FIRDAPSE ® (amifampridine) 10 mg tablets prior to expi…

Director — Daniel J. Curran, M.D.: The filing discloses the appointment of a new director to the board, which is a routine governance event and not a departure of an executive.

Other Events On June 1, 2025, Gary Ingenito, MD, PhD, the Chief Medical and Regulatory Officer of Catalyst Pharmaceuticals, Inc. (the “ Company ”) retired from his position. Dr. Ingenito reported to the Company that his decision to retire was not the result of any disagreements between Dr. Ingenito, on the one hand, and the Company, the Company’s management, or the Company’s Board of Directors, on the other hand, as to any matter relating to the Company’s operations, finances, policies, or pr…

Director — Charles B. O'Keeffe: The filing reports the routine annual election of directors and the orderly retirement of a long-serving independent director without any disagreement or shock.

Director — Charles B. O’Keeffe: The filing discloses the planned retirement of a long-serving independent director (Lead Independent Director) at the end of his term, which is an orderly succession rather than a sudden loss of a senior executive.

Other Events On January 8, 2025, the Company issued a press release announcing that it and its licensor, SERB S.A. (“SERB”) have entered into a Settlement Agreement with Teva Pharmaceuticals USA, Inc. and Teva Pharmaceuticals, Inc. (collectively “Teva”). This agreement resolves the patent litigation brought by the Company and SERB in response to Teva’s Abbreviated New Drug Application (“ANDA”) seeking approval to market a generic version of FIRDAPSE® (amifampridine) 10 mg tablets prior to the…

Director: The filing discloses the routine election of directors at the annual meeting, which is a standard governance event rather than a departure or executive change.