Cytokinetics Inc., of South San Francisco, said it began enrolling the expansion phase of COSMIC-HF (Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure). The double-blind, randomized, placebo-controlled, multicenter phase II trial is designed to assess the pharmacokinetics and tolerability of omecamtiv mecarbil oral dosing in patients with heart failure and left ventricular systolic dysfunction.