Filed pursuant to Rule 433

Registration File No. 333-234537

Relating to the

Preliminary Prospectus Supplement

dated November 6, 2019

(To Prospectus dated November 6, 2019)

PRICING TERM SHEET

November 7, 2019

Cytokinetics, Incorporated

Offering of

$120,000,000 Aggregate Principal Amount of

4.00% Convertible Senior Notes due 2026

The information in this pricing term sheet supplements Cytokinetics, Incorporated’s preliminary prospectus supplement, dated November 6, 2019 (the “Preliminary Prospectus Supplement”), and supersedes the information in the Preliminary Prospectus Supplement to the extent inconsistent with the information in the Preliminary Prospectus Supplement. Terms used, but not defined, in this pricing term sheet have the respective meanings set forth in the Preliminary Prospectus Supplement. As used in this pricing term sheet, “we,” “our” and “us” refer to Cytokinetics, Incorporated and not to its subsidiaries. Cytokinetics, Incorporated has increased the size of the offering to $120,000,000 (or $138,000,000 if the underwriters fully exercise their over-allotment option). The final prospectus supplement relating to the offering will reflect conforming changes relating to such increase in the size of the offering.

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If such make-whole fundamental change effective date or stock price is not set forth in the table above, then:

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Notwithstanding anything to the contrary, in no event will the conversion rate be increased to an amount that exceeds 120.8459 shares of our common stock per $1,000 principal amount of Notes, which amount is subject to adjustment in the same manner as, and at the same time and for the same events for which, the conversion rate is required to be adjusted pursuant to the provisions described in the Preliminary Prospectus Supplement under the caption “Description of Notes—Conversion Rights—Conversion Rate Adjustments—Generally.”

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We have filed a registration statement (including a prospectus) and the Preliminary Prospectus Supplement with the SEC for the offering to which this communication relates. Before you invest, you should read the Preliminary Prospectus Supplement and the prospectus in that registration statement and other documents we have filed with the SEC for more complete information about us and this offering. You may get these documents free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, we, any underwriter or any dealer participating in the offering will arrange to send you the Preliminary Prospectus Supplement (or, when available, the final prospectus supplement) and the accompany prospectus upon request to: Morgan Stanley & Co. LLC, 180 Varick Street, 2nd Floor, New York, New York 10014, Attention: Prospectus Department; or to Mizuho Securities USA LLC, 320 Park Avenue, 12th Floor, New York, New York 10022-6815, Attention: Equity Capital Markets, or by telephone: (212) 205-7600, or by email: US-ECM@us.mizuho-sc.com.

You should rely only on the information contained or incorporated by reference in the Preliminary Prospectus Supplement and the accompanying prospectus, as supplemented by this pricing term sheet, in making an investment decision with respect to the Notes.

Neither this pricing term sheet, nor the Preliminary Prospectus Supplement and accompanying prospectus constitute an offer to sell or a solicitation of an offer to buy any Notes in any jurisdiction where it is unlawful to do so, where the person making the offer is not qualified to do so or to any person who cannot legally be offered the Notes.

ANY DISCLAIMERS OR OTHER NOTICES THAT MAY APPEAR BELOW ARE NOT APPLICABLE TO THIS COMMUNICATION AND SHOULD BE DISREGARDED. SUCH DISCLAIMERS OR OTHER NOTICES WERE AUTOMATICALLY GENERATED AS A RESULT OF THIS COMMUNICATION BEING SENT VIA BLOOMBERG OR ANOTHER EMAIL SYSTEM.

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