Bristol Myers bags FDA nod for blockbuster-to-be cardio drug Camzyos

After a brief delay in November, Bristol Myers Squibb has won approval for one of the year’s most anticipated drugs.

The FDA on Thursday granted Bristol Myers Squibb’s Camzyos a green light to treat symptomatic obstructive hypertrophic cardiomyopathy (obstructive HCM). Formerly known as mavacamten, the drug represents a potential blockbuster addition to BMS’ cardiovascular stable, which needs fresh blood ahead of top-seller Eliquis’ plunge off the patent cliff later this decade.

Camzyos was at the heart of BMS’ $13.1 billion MyoKardia acquisition back in 2020. The HCM drug is one of four new or near-term Bristol launches that the company figures can reach peak sales of more than $4 billion alone or in combinations, BMS said in January.

After Revlimid's recent loss of exclusivity, BMS is counting on Camzyos and other meds to help cushion the fall.

Traditionally, HCM treatment has revolved around mitigating symptoms with drugs like beta-blockers or calcium channel blockers, Samit Hirawat, M.D., chief medical officer at Bristol Myers, explained in an interview. Camzyos, meanwhile, selectively inhibits cardiac myosin to trigger functional and symptomatic improvements, he said.

For patients with hypertrophic cardiomyopathy, muscle fibers in the heart increase in number and thicken, which cause the walls and septum separating the left and right heart to thicken. This in turn reduces the space available for blood in the organ, resulting in higher pressure against which the heart has to work, Hirawat said.

Patients with HCM struggle with symptoms like shortness of breath, weakness, exhaustion and the inability to do daily physical activities like climbing stairs, lifting weights or playing sports.

Camzyos, for its part, works by binding to the protein myosin and blocking the actin-myosin interactions responsible for HCM, Hirawat said.

“Hypertrophic cardiomyopathy is a disease that goes undiagnosed for a very long time,” Hirawat pointed out. Many patients are diagnosed in the middle of their lives and or go undiagnosed.

Because HCM often flies under the radar, education efforts will be paramount to the drug’s rollout, Hirawat said.

“The overall education around hypertrophic cardiomyopathy needs to increase because of a very large number of people in the community that are going undiagnosed with the disease,” he said, adding, “even those who have been symptomatic because of let’s say shortness of breath or other symptomatology may not seek a cardiologist’s opinion.”

On the awareness front, Bristol in November rolled out its ‘Could It Be HCM” website, which offers symptom education, patient resources and more. The company is planning other awareness efforts, too, Hirawat said.  

The FDA based its decision on data from Myokardia’s phase 3 Explorer-HCM study, which showed the medicine delivered improvements in symptoms, functional status, and quality of life versus placebo.

Bearing a boxed warning for the risk of heart failure, Camzyos will only be available under a Risk Evaluation and Mitigation Strategy (REMS) program, the company noted in a release.

That’s because the med essentially “relaxes” the heart, Hirawat said. If the heart becomes too relaxed, its output will decrease as measured by injection fraction, the CMO explained.

Back in November, the FDA revealed Camzyos would miss its expected January approval deadline because it needed time to review updates on Bristol’s REMS program, which was included in the company’s original filing.

Generally speaking, the drug has been well-tolerated, Hirawat said. “[C]ertainly we want to make sure that the benefits always outweigh the risk and therefore the REMS program is being implemented in parallel,” he explained.

Meanwhile, BMS is already angling to grow Camzyos’s label. The company plans to kickstart a phase 3 study in nonobstructive hypertrophic cardiomyopathy later this year and recently launched a mid-phase proof-of-concept study in heart failure with preserved ejection fraction.