Anna Kostera-Pruszczyk, MD, PhD, of the Medical University of Warsaw in Poland, and colleagues conducted a phase 2/3 trial to evaluate the efficacy and safety of efgartigimod in pediatric patients with anti-acetylcholine receptor antibody–positive (AChR-Ab+) generalized MG. The researchers presented the interim study findings at the 2026 European Academy of Neurology Congress.
The study involved two juvenile patients aged 2 to 17 years. The study used a staggered design.
In part A, the researchers collected data on patient response to a single confirmatory dose for 8 weeks or longer. In part B, the study team also evaluated the efficacy of a multiple-dose treatment response for 18 weeks or longer.
The findings showed that efgartigimod use led to a decline in both AChR-Ab and overall IgG serum levels. Other data from part B of the study indicated that the average overall Myasthenia Gravis Activities of Daily Living score decreased by -3.5 from baseline to 1 month during cycle 1 and −4.0 during cycle 2.
Notably, 80% of the cycle 2 cohort and roughly 73% of the cycle 1 group reached minimal symptom expression.
“Efgartigimod treatment was well tolerated in adolescents and resulted in decreased levels of both total IgG and AChR-? Abs, similar to those observed in adult studies. Clinically meaningful improvements in MG-? ADL and QMG occurred, with many participants achieving MSE. Efgartigimod may address an unmet need in juvenile gMG therapy,” the researchers wrote.