CYTOKINETICS INC

(c) In this Item 5(c) of this quarterly report on Form 10-Q, the terms “officers”, “rule 10b5-1 trading arrangements” and “non-Rule 10b5-1 trading arrangements” have the meanings ascribed to them in Item 408 of Regulation S-K.

The following directors and officers adopted into or terminated a Rule 10b5-1 trading arrangement during the second quarter of 2025:

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Andrew Callos – Mr. Callos terminated an existing 10b5-1 trading arrangement, which had been adopted on December 12, 2024, on September 2, 2025. Mr. Callos adopted a new Rule 10b5-1 trading arrangement on September 5, 2025 that was intended to satisfy the affirmative defense provided for under Rule 10b5-1(c) (the “Callos Plan”). The Callos Plan provides for the sale of up to 219,833 shares of our common stock at pre-specified dates during the term of the plan. The Callos Plan will terminate on the earlier of (x)December 1, 2026 and (y) the sale of all securities that are subject to the plan.

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John T. Henderson – Dr. Henderson adopted a Rule 10b5-1 trading arrangement on September 2, 2025 that was intended to satisfy the affirmative defense provided for under Rule 10b5-1(c) (the “Henderson Plan”). The Henderson Plan provides for the sale of up to 28,750 shares of our common stock. The Henderson Plan will terminate on theearlier of (x)May 18, 2026 and (y) the sale of all securities that are subject to the plan.

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B. Lynne Parshall – Ms. Parshall adopted a Rule 10b5-1 trading arrangement on August 20, 2025 that was intended to satisfy the affirmative defense provided for under Rule 10b5-1(c) (the “Parshall Plan”). The Parshall Plan provides for the sale of up to 20,000 shares of our common stock. The Parshall Plan will terminate on theearlier of (x)September 3, 2026 and (y) the sale of all securities that are subject to the plan.

Certain of our officers have made elections to participate in, and are participating in, our employee stock purchase plan, which may be designed to satisfy the affirmative defense conditions of Rule 10b5-1 under the Exchange Act or may constitute non-Rule 10b5–1 trading arrangements. In addition, certain of our directors have made elections to participate in, and are participating in, our director equity in lieu of cash retainer option program (as described in the “Director Compensation” section of our Proxy Statement for our 2024 Annual Meeting), which may be designed to satisfy the affirmative defense conditions of Rule 10b5-1 under the Exchange Act or may constitute non-Rule 10b5–1 trading arrangements.