Enspryng delivered a statistically significant benefit in improving symptoms and daily life metrics when used on top of standard-of-care therapy in gMG patients who are anti-AChR-seropositive, which represents about 80% of the disease population. The phase 3 LUMINESCE trial has met its primary endpoint as measured by the Myasthenia Gravis Activities of Daily Living (MG-ADL) score at 24 weeks.
However, in announcing the positive readout, Roche’s Chugai said the degree of clinical benefit observed “did not reach our expectations.”
Just a few days ago, Roche touted Enspryng’s “best-in-disease potential in MG” during a neurology investor event, a company presentation shows. At that time, Roche highlighted the remaining unmet need in gMG, including about 10% to 30% of patients who fail on standard-of-care therapies, and at least 60% of patients on novel biologics who couldn’t achieve stable remission.
Roche’s labeling of the Enspryng’s data as weak was a relief for other developers of biologics for gMG, such as Johnson & Johnson, UCB and argenx. As Enspryng was tested under the skin once every four weeks in LUMINESCE, it could have held a convenience edge over other once-weekly regimens given either subcutaneously or through intravenous infusions.