FDA Approves New Drug for BMS Cardiomyopathy

On April 29, Bristol-Myers Squibb's (BMS) mavacamten was approved by the FDA for the treatment of adult patients with obstructive hypertrophic cardiomyopathy (oHCM) grades II-III according to the New York Heart Association functional class (NYHA). to improve exercise capacity and symptoms. The product was granted breakthrough therapy designation by CDE in February this year.

Hypertrophic cardiomyopathy is a chronic progressive disease caused by excessive contraction of the heart muscle and obstruction of blood filling in the left ventricle, leading to debilitating symptoms and cardiac dysfunction. It can be classified as obstructive or non-obstructive hypertrophic cardiomyopathy, the most common cause of which is a mutation in the cardiac sarcomeric protein.

Mavacamten is a potential first-in-class, oral, allosteric modulator of cardiac myosin for the treatment of disorders intrinsic to cardiac hypercontraction and impaired diastolic filling. It reduces myocardial contractility by inhibiting the formation of excessive myosin-actin cross bridges. Excessive myosin-actin bridge formation can lead to hypercontraction, left ventricular hypertrophy, and reduced compliance.

The FDA approval is based on data from a pivotal Phase III clinical trial of mavacamten in patients with symptomatic obstructive HCM. The results showed that its primary and all secondary endpoints achieved high statistical significance (p<0.0006), effectively improving the patient's exercise capacity, left ventricular outflow tract pressure difference (LVOTG), NYHA classification, etc.

In August 2020, Liantuo Bio received a license from MyoKardia, a subsidiary of BMS, for US$187.5 million (US$40 million down payment, US$147.5 million in mileage and sales share), and has operations in mainland China, Hong Kong, Macau, Taiwan, Thailand and Singapore develops and commercializes mavacamten.

LianBio is currently conducting a randomized, double-blind, placebo-controlled, multicenter Phase III clinical trial to evaluate the efficacy and safety of mavacamten in Chinese patients with symptomatic obstructive hypertrophic cardiomyopathy. The study will enroll approximately 81 patients and the primary endpoint will be the change from baseline to Week 30 in the left ventricular outflow tract (LVOT) gradient with Valsalva.