Tony Vangeneugden (Belgium)
argenx clinical developmentAuthor Of 1 Presentation
SAFETY AND TOLERABILITY OF EFGARTIGIMOD IN PATIENTS WITH GENERALIZED MYASTHENIA GRAVIS: PHASE 3 ADAPT STUDY RESULTS
- Renato Mantegazza (Italy)
Abstract
Background and Aims:
Efgartigimod, a human IgG1 antibody Fc-fragment, blocks the neonatal Fc receptor, which decreases recycling of IgG and reduces pathogenic autoantibody levels. In a phase 2 study, it demonstrated efficacy and was well tolerated in patients with generalized myasthenia gravis (gMG), an IgG antibody-mediated disease.
Methods:
ADAPT was a phase 3, randomized, double-blind, placebo controlled, global, multicenter 26-week study that evaluated the safety and efficacy of efgartigimod in patients with gMG. Participants were randomized 1:1 to receive four weekly 10 mg/kg infusions of efgartigimod or placebo with subsequent treatment cycles administered according to clinical response.
Results:
167 (129 AChR-Ab+ and 38 AChR-Ab-) patients were randomized. Significantly more patients treated with efgartigimod, compared to placebo, achieved sustained statistically and clinically significant improvement in both MG-ADL and QMG scores. The majority of adverse events (AEs) were mild or moderate. Infections were of special interest and occurred with similar frequency in efgartigimod and placebo treated patients (46.4% and 37.3%, respectively). The type and severity of infections were similar between groups, with no serious or opportunistic infections in the efgartigimod group. Headache was the most common AE (efgartigimod: 28.6%, placebo: 27.7%), but none were serious or required treatment interruption. Most patients experienced headache only once. Infusion related reactions were infrequent, despite the absence of premedication, occurring in 3.6% of efgartigimod and 9.6% of placebo patients, none were serious or required a change in efgartigimod dose and no hypersensitivity or anaphylactic reactions were reported.
Conclusions:
Efgartigimod was not only clinically efficacious, but also well tolerated in patients with gMG.