Abstract-Text (inkl. Referenzen)

Introduction Individualized cyclic administration of efgartigimod, a human IgG1 antibody Fc-fragment that blocks the neonatal Fc receptor, was effective and well tolerated in the ADAPT trial of patients with generalized myasthenia gravis (gMG). ADAPT NXT study (NCT04980495) objective: evaluate the efficacy, safety and tolerability of 10mg/kg IV efgartigimod administered every 2 or 3 weeks (Q2/3W), or a cyclic regimen (4 infusions at weekly intervals with a 4-week intertreatment period).

Methods Adults with gMG who are AChR-Ab+ and have Myasthenia Gravis Activities of Daily Living (MG-ADL) total score of ≥5 (>50% score due to nonocular symptoms) will be recruited (N=72 estimated). Patients will be randomized 3:1 to either the bi-weekly or cyclic dosing regimens. After the initial 21-week period, patients continue the Q2W dosing regimen, with the option to switch to Q3W as tolerated. Concomitant gMG treatment is permitted (nonsteroidal immunosuppressive drugs or steroids [stable dose ≥1 month pre-screening], and/or acetylcholinesterase inhibitors).

Results Primary endpoint: mean change in MG-ADL total score from baseline to week 21 for each regimen. Safety, tolerability, additional clinical efficacy measures (including patient satisfaction), and pharmacokinetic/pharmacodynamic effects will be assessed.

Summary ADAPT NXT will provide important data to inform alternative treatment regimens which may be more convenient for individual patients. Estimated study completion date: 2025.