• Neuro-Ophthalmology/Orbit

    Results from the phase 3, multicenter, double-blind, randomized, placebo-controlled ADAPT trial of the efficacy and safety of efgartigimod (ARGX-113), a human immunoglobulin G1 antibody Fc fragment, in patients with generalized myasthenia gravis (MG) are now available.

    Study design

    The study was conducted in 56 centers in North America, Europe, and Japan, and 167 adult patients were randomized 1:1 to receive efgartigimod 10 mg/kg or placebo, given as once-weekly infusions in 4-week cycles. Inclusion criteria were a Myasthenia Gravis Activities of Daily Living (MG-ADL) score of ≥5 (>50% non-ocular) and a stable dose of 1 or more treatments for generalized MG. The primary endpoint was the proportion of acetylcholine receptor antibody–positive patients who showed a ≥2-point improvement in MG-ADL score after 4 weeks.

    Outcomes

    Sixty-eight percent of the efgartigimod group were MG-ADL responders, compared with 30% of the placebo group. There were similar rates of adverse events (AEs) in both groups (77% in patients given efgartigimod group and 84% in patients given placebo; the most common AEs were headache and nasopharyngitis). There were no deaths.

    Limitations

    The main limitations of the ADAPT trial were its short follow-up period, the non-inclusion of acetylcholine receptor antibody–negative patients in the primary endpoint, and the lack of treatment of patients in the placebo group afterward via a crossover arm.

    Clinical significance

    Ophthalmologists should be aware of emerging treatment modalities for MG that extend beyond traditionally prescribed medications.