CYTOKINETICS INC Debt Disclosure

Note 7 — Debt

Convertible Notes

On November 13, 2019, we issued $138.0 million aggregate principal amount of 2026 Notes. On July 6, 2022, we issued $540.0 million aggregate principal amount of 2027 Notes and used approximately $140.3 million of the net proceeds from the offering of 2027 Notes and issued 8,071,343 shares of common stock to repurchase approximately $116.9 million aggregate principal amount of the 2026 Notes pursuant to privately negotiated exchange agreements entered into with certain holders of the 2026 Notes concurrently with the pricing of the offering of the 2027 Notes.

On September 19, 2025, we issued $750.0 million aggregate principal amount of 2031 Notes and used approximately $402.5 million of the net proceeds from the offering of 2031 Notes and issued 2,168,806 shares of common stock to repurchase approximately $399.5 million aggregate principal amount of the 2027 Notes pursuant to privately negotiated exchange agreements entered into with certain holders of the 2027 Notes concurrently with the pricing of the offering of the 2031 Notes. This resulted in recording a debt conversion expense in the third quarter of 2025 of $121.2 million, consisting of the difference between the consideration provided to the holders pursuant to the exchange agreements and the if-converted value of the 2027 Notes under the original terms.

As of December 31, 2025, there remains $21.1 million aggregate principal amount of 2026 Notes outstanding and reflected as current in the consolidated balance sheet, $140.5 million of aggregate principal amount of 2027 Notes outstanding, and $750.0 million of aggregate principal amount of 2031 Notes outstanding.

2031 Notes

The 2031 Notes are our senior unsecured obligations and shares equal in right of payment with our other indebtedness, including the 2026 Notes and 2027 Notes. The 2031 Notes bear interest at a rate of 1.75% per year, payable semiannually in arrears on April 1 and October 1 of each year, beginning April 1, 2026. The 2031 Notes will mature on October 1, 2031, unless earlier converted, redeemed, or repurchased. Holders of the 2031 Notes may convert their 2031 Notes, under certain circumstances, into cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on an initial conversion rate of 14.6156 shares per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $68.42 per share.

The 2031 Notes are not redeemable prior to October 6, 2028 by the Company. On or after October 6, 2028, the 2031 Notes will be redeemable, in whole or in part (subject to the Partial Redemption Limitation), at our option at any time and from time to time, and, in the case of any partial redemption, on or before the 40th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the 2031 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if the 2031 Notes are freely tradable and all accrued and unpaid additional interest, if any, has been paid in full, as of the first interest payment date occurring on or before such redemption notice date, and the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we may send the related redemption notice; and (ii) the trading day immediately before the date we may send such notice.

The conversion rate for the 2031 Notes, 2027 Notes, and 2026 Notes will be subject to adjustment upon the occurrence of certain specified events. In addition, upon the occurrence of a make-whole fundamental change (as defined in the each respective indenture for the 2026 Notes, 2027 Notes and 2031 Notes), we will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its notes in connection with such make-whole fundamental change.

The effective interest rate of the 2031 Notes was 2.23% as of December 31, 2025. As of December 31, 2025, the unamortized debt issuance cost for the 2031 Notes was $19.6 million and will be amortized over approximately 5.8 years.

2027 Notes

As of December 31, 2025, the 2027 Notes aggregate principal balance was $140.5 million. The 2027 Notes are our senior unsecured obligations and shares equal in right of payment with our other indebtedness, including the 2026 Notes and the 2031 Notes. The 2027 Notes bear interest at a rate of 3.50% per year, payable semiannually in arrears on January 1 and July 1 of each year, beginning on January 1, 2023. The 2027 Notes will mature on July 1, 2027, unless earlier converted, redeemed or repurchased. The 2027 Notes are convertible into cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on the applicable conversion rate(s). The initial conversion rate for the 2027 Notes is 19.5783 shares of our common stock per $1,000 principal amount of such Notes, which is equivalent to an initial conversion price of approximately $51.08 per share.

The 2027 Notes are redeemable, in whole or in part (subject to the Partial Redemption Limitation), at our option at any time, and from time to time, and, in the case of any partial redemption, on or before the 60th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the 2027 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we may send the related redemption notice; and (ii) the trading day immediately before the date we may send such notice.

The effective interest rate of the 2027 Notes was 4.2% as of December 31, 2025, 2024 and 2023. As of December 31, 2025, the unamortized debt issuance cost for the 2027 Notes was $1.4 million and will be amortized over approximately 1.5 years. In 2025, the conditions allowing holders of the Notes to convert were not met. As a result, the 2027 Notes are not convertible as of December 31, 2025.

2026 Notes

As of December 31, 2025, the 2026 Notes aggregate principal balance was $21.1 million and is presented as a current liability as of December 31, 2025. The 2026 Notes are senior unsecured obligations and bear interest at an annual rate of 4.0% per year, payable semi-annually on May 15 and December 15 of each year, beginning May 15, 2020. The 2026 Notes will mature on November 15, 2026, unless earlier repurchased or redeemed by us or converted at the option of the holders. We may redeem the 2026 Notes prior to the maturity date but we are not required to and no sinking fund is provided for the 2026 Notes. The 2026 Notes may be converted, under certain circumstances, based on an initial conversion rate of 94.7811 shares of common stock per $1,000 principal amount (which represents an initial conversion price of $10.55 per share).

As of December 31, 2025, the holders of the 2026 Notes have the option to convert their 2026 Notes only in the following circumstances: (i) if the last reported sale price per share of our common stock exceeds 130% of the conversion price for at least 20 trading days within a 30-day period; (ii) within 5 consecutive business days following any 10 consecutive trading day period if the trading price per $1,000 principal amount of 2026 Notes during such period falls below 98% of the product of the last reported sale price per share of our common stock and the conversion rate; (iii) upon certain corporate events or distributions on our common stock outlined in the 2026 Indenture; (iv) upon our call for redemption of the 2026 Notes; and (v) from July 15, 2026, until the scheduled trading day immediately preceding the maturity date. In 2025, the sale price condition was met. As a result, the 2026 Notes are convertible as of December 31, 2025 at the option of the holders thereof.

The 2026 Notes are redeemable by the Company, in whole or in part, at our option at any time, and from time to time, and, in the case of any partial redemption, on or before the 60th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the 2026 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we may send the related redemption notice; and (ii) the trading day immediately before the date we may send such notice.

The effective interest rate of the 2026 Notes was 4.6% as of December 31, 2025, 2024, and 2023. As of December 31, 2025, the unamortized debt issuance cost for the 2026 Notes was $0.1 million and will be amortized over approximately 0.9 years. The 2026 Notes are convertible at December 31, 2025 at the option of the holder.

As of December 31, 2025, the estimated fair value of the 2031 Notes, 2027 Notes, and 2026 Notes was $919.7 million, $200.0 million and $127.8 million, respectively, and was based upon observable, Level 2 inputs, including pricing information from recent trades of the Convertible Notes.