AHA: Bristol Myers' $13B MyoKardia heart drug gets along with beta blockers as clock ticks down to FDA decision

Bristol Myers Squibb new sign outside
All patients in the sub-group saw an improvement in peak oxygen uptake, however the study did find that the rates were greater in patients who were not taking beta blockers. (Bristol Myers Squibb)

Turns out Bristol Myers Squibb’s targeted heart drug mavacamten gets along pretty well with traditional beta blocker therapies that are often used to control blood pressure.

This is key as BMS pads the case for an approval of the therapy picked up through the $13 billion acquisition of MyoKardia just over a year ago.

Mavacamten is being tested in obstructive hypertrophic cardiomyopathy, or HCM, an inherited disorder that causes the muscle walls of the heart to thicken, sometimes to the point at which they can obstruct blood flow.

BMS, and MyoKardia before, has presented plenty of data on efficacy, symptom control and other measures for mavacamten, which aims to tackle HCM at its source rather than managing symptoms.

RELATED: ACC 2021: BMS unveils more data for mavacamten, nabbed in $13B MyoKardia buyout

Now, the Big Pharma is rolling out three new presentations at the American Heart Association’s annual Scientific Sessions that provide more information on long-term treatment and how the therapy interacts with other meds. The data come from the phase 3 EXPLORER-HCM and MAVA-LTE studies.

BMS’ Roland Chen, M.D., senior vice president for cardiovascular development, is particularly excited about the beta blocker data from a subgroup in the EXPLORER trial, which he said showed that mavacamten benefited patients regardless of whether they were on the common treatments.

The analysis looked at key biomarkers for left ventricular outflow to make this determination, including NT-proBNP and troponin, which are proteins released by cardiac tissue when damaged and are signals of heart failure.

All patients in the subgroup saw an improvement in peak oxygen uptake; however, the study did find that the rates were greater in patients who were not taking beta blockers.

RELATED: ESC: MyoKardia's mavacamten boosts heart function in phase 3, teeing up 2021 filing

These data show “the benefits that we're seeing overall in this study continued and persisted, regardless of that background therapy on beta blockers,” Chen said in an interview.

Mavacamten seemed to be slightly less effective at improving exercise capacity in patients taking the beta blockers. Chen said this reduction was expected, given the standard treatments’ impact on heart rate response during exercise.

“Beta blockers can block the heart rate increase, when people are exercising at max capacity,” Chen explained. “The importance of this study is that it showed consistently, across the range of endpoints studied … that there was similarity and benefit whether a patient was on beta blockers or not.”

BMS also showcased some long-term data from an extension of the phase 2 MAVERICK-LTE study, which included patients with a nonobstructive form of HCM and had a 48-week data cutoff. Mavacamten was found to have a persistent effect and benefit with a longer duration of therapy.

The same NT-proBNP biomarker was measured in this study, and mavacamten-treated patients recorded improvements in left ventrical relaxation and diastolic function at the cutoff.

RELATED: Bristol Myers strikes $13B MyoKardia buyout to gain heart drug

These data complement long-term follow-up that has been seen in the obstructive population, too, Chen said.

BMS is awaiting an FDA decision in the symptomatic obstructive population, which is due Jan. 28, 2022.

Plenty of companies are chasing success in HCM behind BMS. Cytokinetics, which has struggled after losing two partnerships with Big Pharmas elsewhere in its portfolio, notched a much-needed midphase win with the experimental heart drug CK-274 in July. Lexeo Therapeutics recently added an HCM gene therapy to its pipeline through the acquisition of Stelios Therapeutics.