Cytokinetics Announces Cohort 3 of REDWOOD-HCM is Open to Enrollment

Next Cohort to Enroll Patients on Background Therapy of Disopyramide

SOUTH SAN FRANCISCO, Calif., May 04, 2021 (GLOBE NEWSWIRE) -- Cytokinetics, Incorporated (Nasdaq: CYTK) today announced the opening of enrollment in Cohort 3 of REDWOOD-HCM (Randomized Evaluation of Dosing With CK-274 in Obstructive Outflow Disease in HCM), an ongoing Phase 2 clinical trial of CK-3773274 (CK-274), a next-generation cardiac myosin inhibitor in development for the potential treatment of hypertrophic cardiomyopathy (HCM). Cohort 3 will enroll patients whose background therapy includes disopyramide.

“After completing enrollment in the first two cohorts in REDWOOD-HCM, we are pleased to now begin Cohort 3, which is enrolling patients who are being treated with disopyramide,” said Fady I. Malik, M.D., Ph.D., Cytokinetics’ Executive Vice President of Research & Development. “Given that disopyramide is often prescribed in patients with more severe HCM, the data from Cohort 3 may support the potential use of CK-274 in a broader population of patients with obstructive HCM. Importantly, we do not believe that Cohort 3 is required to refine the dosing strategy that we expect to use in Phase 3 but it will help inform the inclusion criteria for that potentially pivotal clinical trial which we are planning to begin later this year.”

REDWOOD-HCM: Clinical Trial Design

REDWOOD-HCM is a multi-center, randomized, placebo-controlled, double-blind, dose finding clinical trial of CK-274 in patients with symptomatic obstructive HCM (oHCM). The primary objective of the trial is to determine the safety and tolerability of CK-274. The secondary objectives are to describe the concentration-response relationship of CK-274 on the resting and post-Valsalva left ventricular outflow tract gradient as measured by echocardiography during 10 weeks of treatment, to describe the dose response relationship of CK-274, and to evaluate the plasma concentrations of CK-274 in patients with oHCM.

The trial previously completed enrollment in Cohort 1 and Cohort 2, two sequential cohorts. Within each cohort, approximately 20 patients were randomized 2:1 to active or placebo treatment and received up to three escalating doses of CK-274 or placebo based on echocardiographic guidance. Patients received an echocardiogram after two weeks of treatment at each dose to determine whether they would be up-titrated. Overall, the treatment duration is 10 weeks with an echocardiogram to confirm reversibility of effect 2 weeks after the last dose. In Cohorts 1 and 2, patients continued taking background medications exclusive of disopyramide.

Cohort 3 will enroll, in an open label fashion, 8-12 patients whose background therapy includes disopyramide to assess the safety, tolerability, pharmacokinetics, and pharmacodynamic effects of CK-274 in patients taking disopyramide. All patients will receive up to three escalating doses of CK-274, titrated based on echocardiographic guidance. Overall treatment duration will be 10 weeks with a 4-week follow up period after the last dose.

Interim analysis of data from Cohort 1 of REDWOOD-HCM showed patients experienced substantial reductions in the average resting left ventricular outflow tract gradient (LVOT-G) as well as the post-Valsalva LVOT-G (defined as resting gradient