- FDA expanded argenx's VYVGART and VYVGART Hytrulo label to cover all adult gMG serotypes, including anti-MuSK, anti-LRP4 and triple seronegative patients
- Phase 3 ADAPT SERON (n=119) randomized Part A delivered 4 once-weekly IV infusions with the primary endpoint at week 4 (MG-ADL); Part B comprised 2 fixed 4-week cycles with additional cycles allowed ≥1 week after prior dosing across North America, Europe, China and the Middle East
- The trial met its primary endpoint (p=0.0068) with a mean 3.35‑point MG-ADL improvement at week 4, showed sustained improvements across cycles, safety consistent with prior anti-AChR‑positive data, and Hytrulo combines efgartigimod alfa with rHuPH20 (ENHANZE) for subcutaneous delivery
Regulatory update
The FDA approved an expanded label for VYVGART (efgartigimod alfa-fcab) and VYVGART Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) to treat all adult generalized myasthenia gravis (gMG) serotypes: anti-AChR-Ab positive, anti-MuSK-Ab positive, anti-LRP4-Ab positive and triple seronegative.
Key trial results
The approval is based on Phase 3 ADAPT SERON in anti-AChR‑Ab negative gMG (n=119); the study met its primary endpoint (p=0.0068) with a mean 3.35‑point MG‑ADL improvement at week 4 and showed sustained improvements in MG‑ADL and QMG across subsequent treatment cycles.
Study design and population
Part A randomized participants 1:1 to four once‑weekly IV infusions of efgartigimod or placebo with a week‑4 primary readout and 5‑week follow‑up; Part B was open‑label with two fixed 4‑week cycles and additional cycles allowed ≥1 week after the prior administration; enrolled patients had confirmed MG, MG‑ADL ≥5 and were on stable gMG therapy.
Safety and administration
Tolerability across serotypes was consistent with established anti‑AChR‑positive data; common adverse events included respiratory tract infection, headache and urinary tract infection, with risks of infection, hypersensitivity and infusion/injection reactions noted; Hytrulo pairs efgartigimod with rHuPH20 (ENHANZE) for subcutaneous delivery and is available as a self‑injectable option.
Access and registries
Support resources include a patient access program and a pregnancy exposure registry for women treated during pregnancy.
