Roche and Chugai report discontinuation of emugrobart development in SMA and FSHD after Phase II MANATEE and MANOEUVRE studies failed to demonstrate consistent functional benefits, while obesity trials continue
Written By: Pharmacally Medical News Desk
Roche has decided to discontinue the clinical development of emugrobart (GYM329), an investigational anti-latent myostatin sweeping antibody, for the treatment of spinal muscular atrophy (SMA) and facioscapulohumeral muscular dystrophy (FSHD), according to an announcement from Chugai Pharmaceutical Co., Ltd.
The decision follows a detailed evaluation of data from the Phase II/III MANATEE study (Part 1) in SMA (NCT05115110) and the Phase II MANOEUVRE study in FSHD (NCT05548556). While emugrobart demonstrated clear target engagement by reducing mature myostatin levels, the studies did not show sufficiently consistent or robust improvements in muscle growth or exploratory functional outcomes across participants. Based on these findings, Roche concluded that the results do not provide enough confidence to advance the program into Phase III development for these neuromuscular conditions.
Across both trials, emugrobart showed a favorable safety profile. The therapy was generally well tolerated, and there were no serious adverse events or treatment discontinuations related to the drug. The decision to halt development in SMA and FSHD was therefore based on lack of meaningful functional efficacy rather than safety concerns.
Despite the setback in neuromuscular diseases, development of emugrobart in obesity will continue. Researchers believe the biological rationale remains strong in this indication because obesity differs fundamentally from neuromuscular disorders. In obesity, muscle quality is typically not impaired by neurodegenerative or myopathic processes, and circulating myostatin levels are generally higher, potentially making anti-myostatin therapies more effective.
A Phase II clinical program (NCT06965413) evaluating emugrobart in obesity is ongoing and will proceed as planned.
Chugai also noted that Roche’s decision is not expected to affect its consolidated financial forecast for the fiscal year ending December 2026, which was announced on January 29, 2026.
References
Notice Regarding Discontinuation of Development of GYM329 (Emugrobart) in Spinal Muscular Atrophy (SMA) and Facioscapulohumeral Muscular Dystrophy (FSHD), 23 March 2026, https://www.chugai-pharm.co.jp/english/news/detail/20260323083000_1236.html
A Study to Evaluate RO7204239 in Participants with Facioscapulohumeral Muscular Dystrophy (MANOEUVRE), ClinicalTrials.gov ID NCT05548556, https://clinicaltrials.gov/study/NCT05548556
A Study to Investigate the Safety and Efficacy of RO7204239 in Combination with Risdiplam (RO7034067) in Participants with Spinal Muscular Atrophy (MANATEE), ClinicalTrials.gov ID NCT05115110, https://clinicaltrials.gov/study/NCT05115110