Material Event - Form 8-K

Item 8.01 Other Events.

On May 8, 2024, Cytokinetics, Incorporated (the "Company") announced topline data from the Phase 1 study of CK-4021586 (CK-586). The study met its primary and secondary objectives to assess the safety, tolerability and pharmacokinetics (PK) of single and multiple oral doses of CK-586. The data support the advancement of CK-586 to a Phase 2 clinical trial in patients with heart failure with preserved ejection fraction (HFpEF) which is expected to begin in Q4 2024. CK-586 is a cardiac myosin inhibitor in development for the potential treatment of a subgroup of patients with HFpEF.

Phase 1 Design and Key Findings

The primary objective of this Phase 1 double-blind randomized, placebo-controlled, multi-part single and multiple ascending dose clinical study was to evaluate the safety, tolerability and PK of CK-586 when administered orally as single or multiple doses to healthy participants. The study design included seven single ascending dose cohorts (10 mg to 600 mg) comprised of 10 participants each, and two multiple-dose ascending cohorts (100 and 200 mg once daily) comprised of 10 participants each. The study met the primary objective, demonstrating that CK-586 was safe and well tolerated in healthy participants with linear PK. Pharmacodynamics were evaluated using echocardiography and consistent with expectations. No serious adverse events were observed, and the stopping criteria were not met in the study.

About CK-4021586 (CK-586)

CK-4021586 (CK-586) is a novel, selective, oral, small molecule cardiac myosin inhibitor designed to reduce the hypercontractility associated with heart failure with preserved ejection fraction (HFpEF). In preclinical models, CK-586 reduced cardiac hypercontractility by decreasing the number of active myosin cross-bridges during cardiac contraction thereby reducing the contractile force, without effect on calcium transients. In some patients, HFpEF is a condition that resembles non-obstructive hypertrophic cardiomyopathy (HCM) in that the patients have higher ejection fractions, thickened walls of their heart, elevated biomarkers, and symptoms of heart failure. In a Phase 2 clinical trial in patients with non-obstructive HCM, aficamten, a cardiac myosin inhibitor also developed by the Company, was well tolerated, improved patient reported outcomes (Kansas City Cardiomyopathy Questionnaire (KCCQ) and New York Heart Association (NYHA) Functional Class) and biomarkers, measures that are also relevant to HFpEF, lending support for this mechanism of action in HFpEF.

Forward-Looking Statements

This filing contains forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995 (the "Act"). Cytokinetics disclaims any intent or obligation to update these forward-looking statements and claims the protection of the Act's Safe Harbor for forward-looking statements. Examples of such statements include, but are not limited to, statements, express or implied, relating to the potential benefits of CK-586 for patients with heart failure with preserved ejection fraction (HFpEF) and our ability to commence a Phase 2 clinical trial of CK-586 in the fourth quarter of 2024, if ever. Such statements are based on management's current expectations, but actual results may differ materially due to various risks and uncertainties, including, but not limited to, potential difficulties or delays in the development, testing, regulatory approvals for trial commencement, progression or product sale or manufacturing, or production of Cytokinetics' drug candidates that could slow or prevent clinical development or product approval; Cytokinetics' drug candidates may have adverse side effects or inadequate therapeutic efficacy; the FDA or foreign regulatory agencies may delay or limit Cytokinetics' ability to conduct clinical trials; Cytokinetics may be unable to obtain or maintain patent or trade secret protection for its intellectual property; standards of care may change, rendering Cytokinetics' drug candidates obsolete; and competitive products or alternative therapies may be developed by others for the treatment of indications Cytokinetics' drug candidates and potential drug candidates may target. For further information regarding these and other risks related to Cytokinetics' business, investors should consult Cytokinetics' filings with the Securities and Exchange Commission.