Material Event (Form 8-K)

Item 8.01 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 not infringe and has not infringed any valid claim of the '697 patent; a judgment declaring that the claims of the '697 patent are invalid; a judgment preliminarily and permanently enjoining the defendants, and those acting in concert with them, from threatening or initiating infringement litigation against the Company or against users, customers, dealers, suppliers, sellers or distributors of the Company's MYQORZO®(aficamten), or charging any of them with infringement of the '697 patent; an award of the Company's costs; a finding that this is an exceptional case, together with an award of the Company's reasonable attorneys' fees under 35 U.S.C. § 285 or otherwise; and such other and further relief as the court may deem just and proper. The Company has also demanded a trial by jury on all triable issues. The Company intends to vigorously assert its legal rights, but the outcome of any litigation is inherently uncertain.

The Company will provide updates regarding this matter, to the extent required or appropriate, in its filings with the U.S. Securities and Exchange Commission, and does not otherwise intend to comment on this matter.