FDA Approves Rystiggo: The Only Treatment for Two Most Common Subtypes of Generalized Myasthenia Gravis in Adults

The FDA approved UCB SA's UCBJF UCBJY Rystiggo (rozanolixizumab-noli) for generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AchR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

The company says Rystiggo is the only FDA-approved treatment in adults for anti-AChR and anti-MuSK antibody-positive gMG, the two most common subtypes of gMG.

The FDA approval is supported by safety and efficacy data from the pivotal Phase 3 MycarinG study. The primary efficacy endpoint was comparing the change from baseline between treatment groups in the MG-ADL total score, a measurement tool that assesses the impact of gMG on the daily functions of 8 signs or symptoms.

A statistically significant difference favoring Rystiggo was observed in the MG-ADL total score change from baseline [-3.4 points in the Rystiggo-treated group at either dose vs. -0.8 points in the placebo-treated group.

Rystiggo will be commercially available in the U.S. during Q3 of 2023. 

Last week, the FDA approved Argenx SE's ARGX Vyvgart Hytrulo (efgartigimod alfa and hyaluronidase-qvfc), an injection for subcutaneous (SC) use for gMG in adult patients who are anti-acetylcholine receptor antibody positive. These patients represent approximately 85% of the total gMG population.