Genentech Halts Emugrobart Development in Rare Genetic Muscle Diseases, Raising Concerns for Obesity Trials
Genentech discontinued emugrobart (anti-myostatin antibody) after it failed to improve muscle growth in phase 2/3 Manatee trial for SMA and phase 2 Manoeuvre trial for FSHD.
The decision was announced in letters to patient communities on March 19, 2026.
Emugrobart is still in two obesity trials:
phase 2 Gyminda (with tirzepatide to preserve muscle during weight loss) and a phase 1 study in type 2 diabetes/obesity patients.
Failure in genetic diseases raises questions about emugrobart's ability to preserve muscle mass amid GLP-1 induced weight loss.
Data from the discontinued trials will be presented at upcoming medical meetings.