FDA Approves New Bristol-Myers Drug for Common Inherited Heart Disease

The disease, called hypertrophic cardiomyopathy, or HCM, causes the heart muscles to thicken excessively and make it difficult for the organ to pump blood. The condition affects about 1 in 500 people. It is the most common cause of sudden cardiac death in young people, including athletes, though it is rare.

The new drug, which carries the chemical name mavacamten and which Bristol will market as Camzyos, was the centerpiece of the company’s $13.1 billion acquisition of MyoKardia in 2020. Bristol is counting on sales to help offset several upcoming patent expirations for key products.

Camzyos could generate more than $2 billion in sales by 2026, according to analysts at Bernstein. Bristol said it priced Camzyos at $89,500 per year.

“This is a humongous step in the direction of trying to find transformative medicines for patients with obstructive hypertrophic cardiomyopathy,”

Samit Hirawat,

Bristol’s chief medical officer, said in an interview.

The thickened heart muscles in HCM patients become stiff and make it difficult for their hearts to pump blood. Many patients don’t have symptoms, but others experience shortness of breath, chest pains and abnormal heart rhythms.

The condition is also associated with a higher risk for an irregular and often rapid heart rhythm, which can lead to blood clots, stroke and other complications.

Until now, doctors treated patients with widely used and inexpensive heart drugs such as beta blockers and calcium-channel blockers. Some patients underwent surgery that, for instance, removes part of the thickened heart muscle.

Doctors said Camzyos could help patients who aren’t helped by the other heart drugs, who experience side effects or who want to avoid surgery.

“I think it will find a spot perhaps not as an alternative but to see if you can hold off surgery if someone wasn’t really ready for that,” said

James Udelson,

chief of cardiology at Tufts Medical Center in Boston and chairperson of the American Heart Association’s HCM Scientific Advisory Group, who wasn’t involved in the drug’s late-stage trial.

Administering the drug may be challenging, Dr. Udelson said, because physicians will need to adjust the dose based on echocardiogram results, which doctors don’t typically do with existing treatments.

“If you have an effective medication that saves you a surgery that’s only being done to improve your quality of life, how wonderful to have another pill option in your armamentarium,” said Dr.

Michelle Kittleson,

director of postgraduate education in heart failure and transplantation at the Smidt Heart Institute at Cedars-Sinai Medical Center in Los Angeles, who wasn’t involved in the drug’s research.

Doctors said they are also unlikely to prescribe Camzyos to young athletes with HCM, because they usually don’t have symptoms.

In HCM patients, heart walls are thicker and the organ contracts more forcefully, decreasing the flow of blood out of the heart. Camzyos blocks a protein, called myosin, that is believed to play a key role in causing the contractions.

The drug’s approval is for a common form of the disease, known as obstructive HCM. In that form, blood flow is partially blocked from the left ventricle, the heart’s main pumping chamber, to the aorta.

The FDA based its decision on a 251-subject late-stage study from Bristol that found Camzyos significantly improved heart function, quality of life and oxygen consumption in patients with HCM after 30 weeks.

No serious safety concerns were observed, the researchers said.

Write to Jared S. Hopkins at jared.hopkins@wsj.com