The US Food and Drug Administration (FDA) has accepted Bristol Myers Squibb’s (BMS ) supplemental new drug application for Camzyos (mavacamten) to reduce patients’ need for septal reduction therapy (SRT ). Camzyos was approved for obstructive hypertrophic cardiomyopathy (HCM ) in April this year, filling a significant unmet need for an underserved subset of cardiomyopathy patients. SRT is either a surgical (septal myectomy) or catheter-based (alcohol septal ablation) procedure—both highly invasive and recommended for most patients with severe symptomatic obstructive HCM. BMS hopes that Camzyos will provide a therapeutic alternative for patients, reducing their need for SRT.

BMS’ filing is based on the results of its Phase III VALOR-HCM study. VALOR-HCM enrolled 112 patients with symptomatic obstructive HCM who met guideline criteria for SRT and had been referred to undergo the procedure. Participants were randomised to receive either Camzyos or placebo. Camzyos significantly improved symptoms in severe obstructive HCM patients and, subsequently, only 18% of participants in the Camzyos treatment group elected to move forward with SRT, compared with 77% in the placebo group. These findings substantiate Camzyos’ ability to improve patients’ symptoms enough that they are no longer SRT-guideline eligible.

Obstructive HCM is one of several subtypes of cardiomyopathy, a cardiovascular condition that impairs the heart’s ability to pump blood. HCM occurs when the walls of the heart become thick and non-flexible and can either be obstructive or non-obstructive in nature, which can be distinguished based on whether blood flow out of the heart is blocked. Camzyos is the only therapy currently on the market for obstructive HCM; before its approval, obstructive HCM was managed either with generic cardiovascular therapies, such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), or via surgical intervention. Obstructive HCM patients can now be prescribed Camzyos once daily with a starting dose of 5mg with titration at 2.5mg, 5mg, 10mg or 15mg.

Camzyos is a first-in-class allosteric modulating myosin inhibitor, which acts by blocking the function of the myosin motor protein central to smooth muscle contraction. This mechanism of action more specifically targets the underlying pathophysiology of HCM compared to generic ACE inhibitors and ARBs, which are used for a range of cardiovascular diseases. Given Camzyos’s first-in-class position, unique mechanism of action and underserved target patient population, GlobalData expects the drug to generate nearly $1bn in sales worldwide by 2025. This number would be further bolstered if the drug were to obtain approval to reduce the need for obstructive HCM patients to undergo SRT.