Roche drops Phase III plans for emugrobart in two muscle wasting diseases
The big pharma company will no longer progress emugrobart to late-stage trials in FSHD and SMA due to a lack of efficacy.
Roche has halted plans to progress its anti-myostatin antibody, Emugrobart (Synonyms: GYM-329, RG6237, RG-70240), to Phase III trials in spinal muscular atrophy (SMA) and facioscapulohumeral muscular dystrophy (FSHD). This decision was based on the outcomes of the Phase II MANOEUVRE trial (NCT05548556) in FSHD and the Phase II/III MANATEE (NCT05115110) study in SMA, which were both assessing if emugrobart could safely prompt improvements in muscular growth.
In the community letters, Roche noted that the decision to discontinue emugrobart’s development in FSHD and SMA was not related to the drug’s safety profile. Roche plans to share data from the MANOEUVRE study at a future medical conference.
Impact on Patients and the Market
This outcome will be disappointing news for patients with FSHD, as there are currently no targeted or disease-modifying therapies (DMT) approved for this indication, which is the third most common form of muscular dystrophy and estimated to impact four in every 100,000 individuals, as per the Muscular Dystrophy Association.
In a statement addressing emugrobart’s discontinuation in FSHD, Dr. Lucienne Ronco, chief science officer of the FSHD Society, said that emugrobart did trigger an increase in circulating myostatin levels, but that the drug “did not boost muscle growth after 52 weeks of treatment”.
According to bank holding company Truist, emugrobart’s discontinuation could pave the way for Scholar Rock’s apitegromab to become the lead anti-myostatin candidate currently in development for FSHD. Other investors appear to agree, as Scholar Rock’s stock value jumped 16% from $39.15 at market open on 18 March to $45.50 at market close on the same day. Scholar Rock is currently gearing up to initiate a Phase II study on its anti-myostatin candidate, apitegromab in FSHD, which the biotech hopes to initiate in mid-2026.
Meanwhile, US regulators have approved several disease-modifying therapies for use in patients with SMA, including Ionis and Biogen’s Spinraza (nusinersen), Novartis’ Zolgensma (onasemnogene abeparvovec) and Roche & PTC’s Evrysdi (risdiplam). Most recently, Novartis secured the US regulatory blessing for its one-time gene replacement therapy, Itvisma (onasemnogene abeparvovec-brve) in the indication.
Roche Bets on Emugrobart’s Obesity Potential
While emugrobart’s discontinuation in FSHD and SMA will be a setback for Roche, the company is still eyeing commercial success for the drug. Currently, Roche is evaluating the potential of emugrobart in combination with Eli Lilly’s best-selling weight loss drug, Zepbound (tirzepatide) in obesity via the Phase II GYMINDA (NCT06965413) trial, which is looking at how well the two drugs can prompt weight loss in patients with at least one weight-related comorbidity. This study is set for primary completion in August 2026, as per ClinicalTrials.gov.
Roche is also sizing up the type 2 diabetes market, as the company is currently performing a Phase I (NCT07137585) study on emugrobart in the indication, which the company expects to reach a primary conclusion in September 2026.
