LianBio announced the first patient has been dosed in the Phase 3 EXPLORER-CN clinical trial of mavacamten in Chinese patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Mavacamten is a potential first-in-class, oral, allosteric modulator of cardiac myosin in development for the treatment of conditions in which excessive cardiac contractility and impaired diastolic filling of the heart are the underlying cause of disease. In the global Phase 3 EXPLORER-HCM trial of mavacamten in oHCM patients with New York Heart Association (NYHA) class II–III symptoms, mavacamten met all primary and secondary endpoints with statistical significance and demonstrated clinically meaningful improvement in functional status, symptoms, and quality of life.

LianBio in-licensed rights from MyoKardia, now a wholly owned subsidiary of Bristol-Myers Squibb, for the development and commercialization of mavacamten in Mainland China, Hong Kong, Macau, Taiwan, Thailand and Singapore. EXPLORER-CN is a Phase 3 multicenter, double-blind, randomized, placebo-controlled registrational study designed to evaluate the safety and efficacy of mavacamten in Chinese patients with symptomatic oHCM. EXPLORER-CN will enroll approximately 81 patients.

The primary endpoint is the change in Valsalva left ventricular outflow tract (LVOT) gradient from baseline to week 30. Eligible patients will continue in a long-term extension treatment period. LianBio is also conducting a concurrent pharmacokinetic (PK) study of mavacamten in healthy Chinese volunteers.

The PK study completed subject dosing in November 2021.