Argenx: FDA Expands Vyvgart Indication to All Myasthenia Gravis Serotypes

An Approval Covering All Disease Serotypes

The approval is based on a supplemental Biologics License Application (sBLA) that expands the indication of Vyvgart to all serotypes of adults with generalized myasthenia gravis (gMG): patients positive for anti-AChR-Ab, anti-MuSK-Ab, anti-LRP4-Ab, and triple-seronegative.

This expansion is supported by data from the phase 3 ADAPT SERON study, the largest study conducted to date in patients with gMG without detectable anti-acetylcholine receptor antibodies. The study included 119 patients across North America, Europe, China, and the Middle East.

Patients treated with Vyvgart in this study showed rapid, significant, and sustained improvements in their gMG symptoms, including speech, vision, physical function, and swallowing. The treatment also demonstrated good tolerability across all serotypes, with a safety profile consistent with that established in patients with gMG positive for anti-AChR-Ab.

Evaluation Criteria and Treatment Modalities

The ADAPT SERON study met its primary endpoint (p = 0.0068), demonstrating that patients treated with Vyvgart achieved a statistically significant improvement in the total MG-ADL (Myasthenia Gravis Activities of Daily Living) score at week 4 compared to placebo.

In the overall population covering all serotypes, the average improvement in the MG-ADL score at week 4 was 3.35 points. Improvements were also observed in the MG-ADL and QMG (Quantitative Myasthenia Gravis) scores in subsequent treatment cycles.

Vyvgart is available in three administration options, including Vyvgart Hytrulo in a pre-filled auto-injection pen. Argenx also offers a patient support program called 'My Vyvgart Path' to assist with access and coverage questions.