Vyvgart(efgartigimod PH20 SC)

Vyvgart (efgartigimod PH20 SC) is indicated as an add-on to standard therapy for the treatment of adult patients with generalized Myasthenia Gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody positive. The regulatory review included 2 Phase 1 studies, 1 Phase 2 study, and 1 Phase 3 study, with a planned enrollment of approximately 150 patients. A total of 167 patients were enrolled, with 91.0% completing treatment and 93.4% completing the study.

Efficacy findings include a mean maximum reduction in total IgG of 61.3% in AChR-Ab seropositive patients, and a mean maximum reduction in acetylcholine receptor antibodies of 57.6% in the same population. Total IgG reduction in gMG patients ranged from 60% to 70%. The MG-ADL responder rate in the PP population for AChR-Ab seropositive patients was 65.5% (C1) and 34.0% (C1). For missing-is-failure imputation, the MG-ADL responder rate was 61.5% (C1) and 29.7% (C1).

Safety data indicated an incidence of treatment-induced ADAs of 20.5%, compared to 7.3% in the placebo group. The incidence of treatment-induced NAbs was 7.2%, versus 3.7% in the placebo group. Discontinuation due to lack of efficacy in the efgartigimod group was 8.3% in one study, while the overall discontinuation rate in the efgartigimod group in C1 of another study was 6%, compared to 12% in the placebo group. The CHMP accepted the absence of dedicated QTc, ADME/renal/hepatic impairment, and DDI studies.