HCM Patients Experience Cardiovascular Comorbidities

Hypertrophic cardiomyopathy (HCM) is a chronic, progressive disease in which excessive contraction of the heart muscle can lead to the development of debilitating symptoms and cardiac dysfunction. In the obstructive form disease, the thickened heart wall can block or reduce the flow of blood from the left ventricle, the heart’s main pumping chamber, into the aorta and the rest of the body..

It’s estimated that 1 in every 500 people have hypertrophic cardiomyopathy, but a large percentage of patients may be undiagnosed, according to the American Heart Association. Of those diagnosed, two-thirds have the obstructive form of the disease.

Cytokinetics, a Bay Area biotech company that is developing an HCM medication, released data from a retrospective observation of patients with obstructive HCM in June. The company’s research showed that after a two-year follow-up period, there was an increase in cardiovascular comorbidities and medication use.

Patients were identified by using claims data from the HealthCore Integrated Research Database, a database representing more than 50 million people who are covered by private insurers or a Medicare Advantage plan.

Of the 1,841 patients identified with obstructive HCM, cardiovascular comorbidities were common at the two-year follow-up, including hypertension (64%), coronary artery disease (31%), atrial fibrillation (26%), heart failure (24%), and diabetes (21%).

Between a one-year 12-mont and two-year follow up, the use of medications increased, including beta-blockers (59% vs 70%), calcium channel blockers (29% vs 33%), anticoagulants (14% vs 22%), and antiarrhythmics (all: 6% vs 10%; disopyramide: 1% vs 3%).

The HCM medication that Cytokinetics is developing is called aficamten. The company has released data from a phase 2 trial that showed found that treatment with aficamten for 10 weeks resulted in reductions from baseline compared with placebo in the average resting left ventricular (LV) outflow tract pressure gradient. The majority of patients treated with medication (78.6% in cohort 1 and 92.9% in cohort 2) achieved the target goal of treatment.

Cytokinetics is current enrolling a third cohort of patients who have been previously treated with disopyramide.

Another HCM therapy in development is Bristol Myers Squibb’s mavacamten, a potential first-in-class therapy that addresses the excessive contraction of the heart that leads to severe disease where the blood flow is obstructed.

The FDA accepted Bristol Myers Squibb’s new drug application (NDA) for mavacamten in March. The agency’s target date for a decision on that application (the PDUFA date) is January 28, 2022.

The NDA is based on data from a phase 3 clinical trial, which enrolled 251 patients. Results from the trial showed that mavacamten demonstrated a robust treatment effect, with clinically meaningful improvements in symptoms, functional status, and quality of life, as well as the ability to relieve left ventricular obstruction. Investigators found that all primary and secondary endpoints were met. The data was published last year in The Lancet.