Cytokinetics successfully completed pricing of an upsized $650 million convertible senior notes offering on September 16, 2025, increasing the size from the initially proposed $550 million to fund the potential commercial launch of aficamten, its cardiac myosin inhibitor for hypertrophic cardiomyopathy.
The South San Francisco-based cardiovascular biopharmaceutical company achieved favorable financing terms with the 1.75% convertible senior notes due 2031. The notes carry an initial conversion price of approximately $68.42 per share, representing a 37.5% premium over the company's closing stock price of $49.76 on September 16, 2025.
Strategic Refinancing Transaction
The offering serves primarily as a refinancing transaction for Cytokinetics' existing 3.50% convertible senior notes due 2027. The company plans to retire approximately $399.5 million of the 2027 notes using $402.5 million of the net proceeds plus 2,168,806 shares of common stock through privately negotiated exchange transactions.
This refinancing extends the debt maturity from 2027 to 2031 while reducing the annual coupon rate from 3.50% to 1.75%. The company estimates net proceeds of approximately $632 million after deducting initial purchasers' discounts and estimated offering expenses.
Funding Aficamten's Commercial Preparations
Cytokinetics is preparing for potential regulatory approvals and commercialization of aficamten following positive results from SEQUOIA-HCM, the pivotal Phase 3 clinical trial in patients with obstructive hypertrophic cardiomyopathy. The cardiac myosin inhibitor is also being evaluated in additional clinical trials enrolling patients with both obstructive and non-obstructive HCM.
The remaining proceeds from the offering will support the potential commercial launch of aficamten, continue and expand its development program, advance the company's broader development and research pipeline, and provide general corporate purposes including working capital.
Note Terms and Conversion Features
The notes will mature on October 1, 2031, unless earlier converted, redeemed, or repurchased. Interest will accrue at 1.75% annually, payable semi-annually on April 1 and October 1, beginning April 1, 2026. The initial conversion rate is 14.6156 shares of common stock per $1,000 principal amount of notes.
Before July 1, 2031, noteholders can convert their notes only under certain circumstances. From July 1, 2031 onward, noteholders may convert at any time until the close of business on the second scheduled trading day before maturity. Cytokinetics retains the option to settle conversions through cash, shares, or a combination at its election.
Broader Pipeline Development
Beyond aficamten, Cytokinetics is developing omecamtiv mecarbil, a cardiac myosin activator for patients with heart failure with severely reduced ejection fraction, and ulacamten, a cardiac myosin inhibitor with a distinct mechanism for potential treatment of heart failure with preserved ejection fraction. The company is also advancing CK-089, a fast skeletal muscle troponin activator for muscular dystrophy and other skeletal muscle function conditions.
The notes offering is scheduled to settle on September 19, 2025, subject to customary closing conditions. Initial purchasers received an option to purchase up to an additional $100 million aggregate principal amount of notes within 13 days of issuance.
