- An experimental drug being developed by South San Francisco-based biotech Cytokinetics improved cardiac function in a mid-stage clinical trial of several dozen patients with a type of heart disease, the company said Monday.
- Treatment with Cytokinetics' drug, called CK-274, led to significant improvements in blood flow from the heart compared to baseline measurements taken at the beginning of the study. No serious side effects related to the therapy were reported, the company said.
- Cytokinetics plans to advance CK-274 into a Phase 3 trial of patients with the condition, known as obstructive hypertrophic cardiomyopathy, before the end of the year.
News of the positive study findings sent Cytokinetics stock higher by nearly 50% Monday, surpassing the price shares traded at before another, more advanced heart drug disappointed last October.
The lackluster data for Cytokinetics' other treatment, called omecamtiv mecarbil, led partner Amgen to hand back rights after more than a decade of development together.
Despite losing its big pharma partner, Cytokinetics still intends to seek FDA approval of the drug. And the biotech's future looks brighter after CK-274 showed encouraging signs of working as intended in hypertrophic cardiomyopathy, or HCM.
Cytokinetics' trial, dubbed REDWOOD-HCM, was designed to test a range of doses of CK-274 over 10 weeks, measuring how treatment affected a measure of participants' blood flow from the left ventricle. Volunteers in the study, who enrolled across 17 sites in North America and Europe, were randomized 2:1 between CK-274 and placebo
In obstructive HCM, the heart's walls thicken, shrinking the space inside the left ventricle and restricting pumping function. CK-274 is designed to bind to a heart muscle protein and thereby reduce the contractility of the myocardia, or muscle tissue.
After 10 weeks of receiving CK-274, nearly 80% of treated patients in one group and 93% in another reached the target goal of treatment. Less than 10% of those who received placebo did, Cytokinetics said. The study measured patients using two different assessments of left ventricle outflow tract gradient, or LVOT-G, a measure of blood flow obstruction.
The reduction in LVOT-G was dose-dependent and sustained through the 10 weeks, the company said.
Dosing is particularly important, as too high a dose could in theory weaken heart muscle. According to Cytokinetics, reductions in left ventricle ejection fraction, which describes how much blood the heart pumps out, were reversible and did not lead to treatment discontinuation. One patient's ejection fraction fell below 50% during treatment, leading researchers to reduce the drug dose given.
Obstructive HCM can lead to a range of symptoms including chest pain, dizziness and fainting during physical exertion. In some, disease progression can lead to heart arrhythmia, stroke and even death. No treatments are approved to treat the hypercontractility that underpins HCM. Last year, however, Myokardia reported the first Phase 3 trial success of a drug that does so, leading Bristol Myers Squibb to buy the company for $13 billion.
An FDA decision on Myokardia's drug, called mavacamten, is expected by late January.