"This study population is an area of great unmet need in heart failure, with mortality rates of about 10% during their hospitalization and 30% at 1 year following discharge," according to Dr. McDonagh.
Nevertheless, it will be important in phase III testing to see how the drug performs in a broader group of heart failure patients, including those with lower estimated glomerular filtration rates, she added.
In an interview, Dr. Teerlink said that before a decision is reached regarding advancement of omecamtiv mecarbil to phase III studies, investigators and the study sponsors first want to see the data from an ongoing phase II dose-finding study of an oral formulation of the drug in chronic heart failure patients. This study, COSMIC-HF (Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure), is still enrolling patients.
"We’ll get the combined data from ATOMIC-AHF and COSMIC-HF and then decide what phase III should look like. There are a lot of options here: IV [intravenous] alone, IV transitioning to chronic oral therapy, or even oral alone," he explained.
"One of the greatest challenges of the ATOMIC-AHF trial has been managing expectations," according to Dr. Teerlink. "Omecamtiv mecarbil is probably one of the most interesting new chemical entities in cardiovascular medicine now, and consequently expectations are very high in the scientific and lay communities."
The studies are sponsored by Amgen and Cytokinetics. Dr. Teerlink has received research grants and/or consulting fees from those companies as well as a handful of others. Dr. McDonagh reported no financial conflicts.