Roche Halts Development of Drug Candidate for Muscle Diseases, Chugai Says

By Adria Calatayud

Roche Holding is stopping clinical development of a drug candidate for two muscle diseases, but plans to continue evaluating it for obesity, Japanese affiliate Chugai Pharmaceutical said.

The Swiss pharmaceutical company decided to discontinue the development of investigational drug emugrobart for spinal muscular atrophy and facioscapulohumeral muscular dystrophy after data from two studies showed the medicine didn't achieve the intended outcomes, Roche's majority-owned Chugai said Monday. The diseases are rare genetic conditions that can cause muscle weakness.

Chugai--which discovered the drug and licensed it to Roche--said the decision doesn't affect the development of emugrobart in obesity, as the scientific rationale for continuing to investigate it remains strong.

Obesity's symptoms and underlying causes are fundamentally different from those of neuromuscular conditions like SMA and FSHD, Chugai said. Muscle quality for patients with obesity isn't primarily affected by nerve or muscle-wasting processes and there is generally more myostatin--a protein that regulates muscle growth--for an anti-myostatin antibody like emugrobart to target, it added.

The development of emugrobart in midstage clinical trials for obesity will continue as planned, Chugai said.

Roche had previously signaled it expected to release data from phase 2 studies in FSHD, SMA and obesity in 2026.

The decision to halt the drug's development for the neuromuscular conditions followed an assessment of data from a phase 2 and 3 study in SMA and a phase 2 study in FSHD, in which the drug reduced mature myostatin but didn't achieved the intended functional outcomes, Chugai said. Muscle growth and exploratory functional efficacy weren't consistent nor robust enough to move the drug to late-stage development, the company said.

The discontinuation wasn't due to safety concerns, as the drug was well tolerated across both studies and there were no serious adverse events or treatment withdrawals, Chugai added.

Write to Adria Calatayud at adria.calatayud@wsj.com

(END) Dow Jones Newswires

March 23, 2026 04:06 ET (08:06 GMT)