As filed with the Securities and Exchange Commission on May 27, 2026

Registration No. 333-   

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

CYTOKINETICS, INCORPORATED

(Exact name of registrant as specified in its charter)

350 Oyster Point Boulevard

South San Francisco, CA 94080

(Address of Principal Executive Offices, Zip Code)

AMENDED AND RESTATED 2015 EMPLOYEE STOCK PURCHASE PLAN

(Full title of the plan)

Robert I. Blum

President and Chief Executive Officer

Cytokinetics, Incorporated

350 Oyster Point Boulevard

South San Francisco, CA 94080

(650) 624-3000

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Aaron K. Briggs

Gibson, Dunn & Crutcher LLP

One Embarcadero Center, Suite 2600

San Francisco, CA 94111

(415) 393-8200

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

EXPLANATORY NOTE

This Registration Statement on Form S-8 is being filed for the purpose of registering an additional 1,000,000 shares of the Common Stock to be issued pursuant to the Amended and Restated 2015 Employee Stock Purchase Plan (the “ESPP”). The shares of the Common Stock previously reserved for issuance under the ESPP were registered on the Registrant’s Registration Statements on Form S-8 previously filed with the Securities and Exchange Commission (the “SEC”) on August 5, 2015 (File No. 333-206101), May 29, 2020 (File No. 333-238786), and June 3, 2024 (File No. 333-279913) (collectively, the “Prior Registration Statements”).

This Registration Statement on Form S-8 relates to securities of the same class as that to which the Prior Registration Statements relate, and is submitted in accordance with General Instruction E to Form S-8 regarding Registration of Additional Securities. Pursuant to General Instruction E of Form S-8, the contents of the Prior Registration Statements, to the extent relating to the registration of Common Stock issuable under the ESPP are incorporated herein by reference and made part of this Registration Statement, except as amended hereby.

Item 8. Exhibits.

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and Exchange Commission on April 17, 2026.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of South San Francisco, State of California, on this 27 day of May, 2026.

POWER OF ATTORNEY

Each person whose signature appears below appoints Robert I. Blum, Sung Lee and John Faurescu, and each of them, any of whom may act without the joinder of the other, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he or she might or would do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated on the dates indicated.

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