Efgartigimod Shows Sustained Improvement in Myasthenia Gravis Patients

Patients with generalized myasthenia gravis (gMG) and acetylcholine-receptor (AChR) autoantibodies have shown sustained improvement when treated with efgartigimod (Vygart), according to a new post-hoc analysis. This analysis, published in the Journal of Neurological Sciences, utilized data from the ADAPT clinical trial and its open-label extension, ADAPT+, to affirm the therapy's safety and efficacy.

Key Findings:

• Sustained Improvement: The analysis indicates that improvements in strength and function are sustained over time in the gMG population, regardless of the definition of response.
• Response Rates: In the ADAPT trial, 68% of AChR-antibody-positive patients responded to efgartigimod in the first treatment cycle, compared to a 30% response rate in the placebo group.
• Assessment Tools: The study used the Quantitative Myasthenia Gravis (QMG) assessment and the MG-Activities of Daily Living (MG-ADL) assessment to measure response, with significant benefits observed on both scales.

Clinical Implications:

• Unmet Need: The findings address a significant unmet need for effective, rapidly acting, and well-tolerated treatments in gMG.
• Broad Patient Population: Efgartigimod demonstrated robust and sustained benefit across a broad patient population, including those with prior immune therapy and varying times since diagnosis.

Study Limitations:

• Assessment Schedule: The authors noted that the assessment schedule in ADAPT and ADAPT+ rendered data capture suboptimal, yet the overall response rates to therapy were notable.

Conclusion: The results of this analysis underscore efgartigimod as an effective therapeutic option for patients with gMG and AChR-Ab+, offering sustained clinical benefits.

References:

1. Dewilde S, Griffiths A, Qi CZ, et al. Post-hoc analyses from the ADAPT clinical study demonstrate aggregate sustained benefit of Efgartigimod in generalized myasthenia gravis. J Neurol Sci. 2024;466:123264. doi:10.1016/j.jns.2024.123264
2. Howard JF Jr, Bril V, Vu T, et al. Safety, efficacy, and tolerability of efgartigimod in patients with generalised myasthenia gravis (ADAPT): a multicentre, randomised, placebo-controlled, phase 3 trial. Lancet Neurol. 2021;20(7):526-536. doi:10.1016/S1474-4422(21)00159-9
3. Howard JF Jr, Bril V, Vu T, et al. Long-term safety, tolerability, and efficacy of efgartigimod (ADAPT+): interim results from a phase 3 open-label extension study in participants with generalized myasthenia gravis. Front Neurol. 2024;14:1284444. doi:10.3389/fneur.2023.1284444