Other Events. On August 13, 2026, Cytokinetics, Incorporated (the “Company”) filed a complaint in the United States District Court for the District of Delaware against Bristol-Myers Squibb Company and MyoKardia, Inc. The complaint seeks a declaratory judgment that the Company does not infringe U.S. Patent No. 12,616,697 (the “’697 patent”) and that the claims of the ’697 patent are invalid. In the complaint, the Company requests, among other things: a judgment declaring that the Company does…

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Other Events. Underwriting Agreement On May 6, 2026, Cytokinetics, Incorporated (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Morgan Stanley & Co. LLC, Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC and Jefferies LLC, as representatives of the several underwriters named therein (collectively, the “Underwriters”), relating to the public offering, issuance and sale (the “Offering”) of 9,859,155 shares of the Company’s common stock, par value $0.…

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Other Events. On December 12, 2025, Cytokinetics, Incorporated ("Cytokinetics" or the "Company") announced that the Committee for Medicinal Products for Human Use of the European Medicines Agency has adopted a positive opinion recommending marketing authorization in the European Union for MYQORZO® (aficamten), a cardiac myosin inhibitor, for the treatment of symptomatic (New York Heart Association, NYHA, class II-III) obstructive hypertrophic cardiomyopathy in adult patients. A final decision…

EVP, Chief Legal and Administrative Officer — Jeffrey J. Hessekiel: The filing discloses the hiring of a new senior executive (EVP/General Counsel) from an external company, which is a standard management addition rather than a departure.

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Entry Into a Material Definitive Agreement. Indenture and Notes On September 19, 2025, Cytokinetics, Incorporated (the “Company”) issued $750.0 million aggregate principal amount of its 1.75% Convertible Senior Notes due 2031 (the “Notes”), which includes the full exercise of the initial purchasers’ option to purchase up to an additional $100.0 million aggregate principal amount of Notes. The Notes were issued pursuant to, and are governed by, an indenture (the “Indenture”), dated as of Septe…

The Notes were issued to the initial purchasers in reliance upon Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), in transactions not involving any public offering. The Notes were resold by the initial purchasers to persons whom the initial purchasers reasonably believe are “qualified institutional buyers,” as defined in, and in accordance with, Rule 144A under the Securities Act. The Company relied on these exemptions from registration based in part on repres…

Creation of a Direct Financial Obligation or an Off-Balance Sheet Arrangement. The disclosure set forth in

Director — James M. Daly: The filing discloses the appointment of a new independent director to fill a vacant board seat, which is a routine governance event rather than an executive departure.

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Other Events. Cytokinetics, Incorporated ("Cytokinetics") today announced that the U.S. Food and Drug Administration ("FDA") has extended the Prescription Drug User Fee Act ("PDUFA") action date for the New Drug Application ("NDA") for aficamten for the treatment of patients with obstructive hypertrophic cardiomyopathy ("oHCM") to December 26, 2025. The FDA recently notified Cytokinetics that additional time is required to conduct a full review of the company’s proposed Risk Evaluation and Mi…

Regulation FD Disclosure. At upcoming investor conferences, Cytokinetics, Incorporated (the “Company”) will be providing, and is hereby furnishing, a brief regulatory update regarding its new drug application for aficamten. During these investor conferences, representatives of the company will make statements consistent with the following: 1. Cytokinetics has completed its midcycle review with the Food and Drug Administration (“FDA”) with respect to the New Drug Application (“NDA”) for aficam…

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Director — Robert E. Landry: The filing discloses the appointment of a new independent director to fill a vacant board seat, which is a routine governance event rather than an executive departure.

Chief Accounting Officer — Robert Wong: The Chief Accounting Officer is departing, but the CFO is assuming the role, indicating an orderly succession rather than a loss of key leadership.

Entry into a Material Definitive Agreement. On November 18, 2024, Cytokinetics, Incorporated (" Cytokinetics ") entered into a License and Collaboration Agreement (the " License Agreement ") with Bayer Consumer Care AG, a member of the Bayer Group (" Bayer "), pursuant to which Cytokinetics granted to Bayer an exclusive license to develop and commercialize Cytokinetics' proprietary small molecule cardiac sarcomere inhibitor known as aficamten (the " Product ") in Japan. Bayer’s exclusive deve…

Director — Santo J. Costa: A director resigned for personal reasons with no reported disagreement, representing a standard board departure rather than a crisis or routine election.

Chief Legal Officer — Brett Pletcher: The filing discloses the external hire of a new Executive Vice President and Chief Legal Officer, which is a standard executive appointment rather than a departure.

and under Exhibit 99.1 shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any future filing under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless the Registrant expressly sets forth in such future filing that such information is to be considered “filed” or incorporated by reference therein.

Other Events. Underwriting Agreement On May 28, 2024, Cytokinetics, Incorporated (the “Company”), closed a public offering pursuant to an underwriting agreement (the “Underwriting Agreement”) with J.P. Morgan Securities LLC, Goldman Sachs & Co. LLC and Morgan Stanley & Co. LLC (collectively, the “Underwriters”) dated May 22, 2024, relating to the public offering, issuance and sale of 9,803,922 shares of the Company’s common stock (“Common Stock”). The price to the public in the offering was $…

SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. CYTOKINETICS, INCORPORATED Date: May 22, 2024. By: /s/ Robert Blum Robert Blum Chief Executive Officer