The phase III placebo-controlled Adapt trial and its open-label extension Adapt+ evaluated the efficacy of efgartigimod, an anti-FcRN, in generalised autoimmune myasthenia gravis. They ended in 2020 and 2022 respectively. Their results were the subject of a post hoc analysis, which showed that, in participants with anti-RACh :
- a significantly higher percentage of patients treated with efgartigimod responded to treatment (i.e. at least -3 points for MG-ADL, -5 points for QMG) compared with patients treated with placebo,
- the duration of response to treatment was greater with efgartigimod than with placebo, the difference being significant,
- these trends were long-lasting (up to 64 weeks) and shared by different sub-groups of participants (with or without prior exposure to biotherapy, diagnosed more or less than 7 years ago).
