Use of Losmapimod as a Disease-Specific Therapy for FSHD

Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary condition characterized by progressive, heterogenous skeletal muscle weakness, typically affecting the face, shoulder girdle, and lower extremities, for which no approved treatments exist. FSHD is caused by aberrant expression of DUX4, a transcription factor that is toxic to muscles. Losmapimod is an investigational (not FDA-approved) drug that inhibits DUX4 regulators; it reduced DUX4 in myotubes in preclinical studies. Researchers now report results of the industry-funded, double-blind, randomized, placebo-controlled, international phase 2b ReDUX4 study of losmapimod in 80 patients aged 18 to 65 years (mean, 46 years; 68% male) with FSHD type 1. Participants were assigned 1:1 t…