Cytokinetics, Incorporated announced that the first participants have been dosed in a Phase 1 study evaluating the pharmacokinetics, safety and tolerability of aficamten in healthy Japanese and Caucasian participants. Phase 1 Clinical Trial Design The primary objective of this Phase 1 double-blind, randomized, placebo-controlled study is to evaluate the pharmacokinetics of aficamten following administration of single ascending doses and multiple doses in 70 healthy Japanese and Caucasian participants. The secondary objective is to evaluate the safety and tolerability of aficamten in healthy Japanese and Caucasian participants.

The study will enroll four cohorts including three single-ascending cohorts and one multiple dose cohort. Cohorts 1, 2 and 3 will enroll 10 Japanese participants and 10 Caucasian participants each, randomized on an 8:2 basis to receive single-ascending doses of aficamten (5 mg, 10 mg and 20 mg, respectively) or placebo. Enrollment of Cohort 2 and Cohort 3 will commence upon evaluation of the safety of the preceding Cohort.

Following the completion of the single ascending dose cohorts, Cohort 4 will enroll 10 healthy Japanese participants randomized on an 8:2 basis to receive single doses of aficamten (5 mg) or placebo, once daily for 14 days. About Aficamten Aficamten is an investigational selective, small molecule cardiac myosin inhibitor discovered following an extensive chemical optimization program that was conducted with careful attention to therapeutic index and pharmacokinetic properties and as may translate into next-in-class potential in clinical development. Aficamten was designed to reduce the number of active actin-myosin cross bridges during each cardiac cycle and consequently suppress the myocardial hypercontractility that is associated with hypertrophic cardiomyopathy (HCM).

In preclinical models, aficamten reduced myocardial contractility by binding directly to cardiac myosin at a distinct and selective allosteric binding site, thereby preventing myosin from entering a force producing state. The development program for aficamten is assessing its potential as a treatment that improves exercise capacity and relieves symptoms in patients with HCM as well as its potential long-term effects on cardiac structure and function. Aficamten was evaluated in SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM), a positive pivotal Phase 3 clinical trial in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM).

Aficamten received Breakthrough Therapy Designation for the treatment of symptomatic obstructive HCM from the U.S. Food & Drug Administration (FDA) as well as the National Medical Products Administration (NMPA) in China. Cytokinetics expects to submit a New Drug Application (NDA) to the FDA in Third Quarter 2024 and a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) in Fourth Quarter 2024. Aficamten is also currently being evaluated in MAPLE-HCM, a Phase 3 clinical trial of aficamten as monotherapy compared to metoprolol as monotherapy in patients with obstructive HCM, ACACIA-HCM, a Phase 3 clinical trial of aficamten in patients with non-obstructive HCM, and CEDAR-HCM, a clinical trial of aficamten in a pediatric population with obstructive HCM, and FOREST-HCM, an open-label extension clinical study of aficamten in patients with HCM.

About Cytokinetics Cytokinetics is a late-stage, specialty cardiovascular biopharmaceutical company focused on discovering, developing and commercializing first-in-class muscle activators and next-in-class muscle inhibitors as potential treatments for debilitating diseases in which cardiac muscle performance is compromised. As a leader in muscle biology and the mechanics of muscle performance, the company is developing small molecule drug candidates specifically engineered to impact myocardial muscle function and contractility. Cytokinetics is preparing regulatory submissions for aficamten, its next-in-class cardiac myosin inhibitor, following positive results from SEQUOIA-HCM, the pivotal Phase 3 clinical trial in obstructive hypertrophic cardiomyopathy.

Cytokinetics is also developing omecamtiv mecarbil, a cardiac muscle activator, in patients with heart failure. Additionally, Cytokinetics is developing CK-586, a cardiac myosin inhibitor with a mechanism of action distinct from aficamten, for the potential treatment of HFpEF, and CK-136, a cardiac troponin activator for the potential treatment HFrEF and other types of heart failure, such as right ventricular failure resulting from impaired cardiac contractility. Cytokinetics continues its longstanding history of pioneering innovation in muscle biology and related pharmacology focused to diseases of muscle dysfunction and conditions of muscle weakness.