FDA Approves Rystiggo for Generalized Myasthenia Gravis

The Food and Administration (FDA) has approved Rystiggo^® (rozanolixizumab-noli) for the treatment of generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

Rystiggo is a humanized monoclonal antibody that binds with high affinity to human neonatal Fc receptor (FcRn) resulting in the reduction of circulating immunoglobulin G (IgG). The approval was based on data from the phase 3 MycarinG study (ClinicalTrials.gov Identifier: NCT03971422), which included 200 adults with gMG.

Patients were randomly assigned 1:1:1 to receive weekly rozanolixizumab 7mg/kg, rozanolixizumab 10mg/kg, or placebo subcutaneously for 6 weeks, followed by an 8-week observation period.

Results showed that treatment with rozanolixizumab met the primary endpoint demonstrating a significant improvement in the Myasthenia Gravis-Activities of Daily Living total score at day 43, with a least square mean difference vs placebo of -2.6 points at both the 7mg/kg dose and 10mg/kg dose (both doses P <.001).

Additionally, a statistically significant difference in the Quantitative Myasthenia Gravis total score at day 43 (key secondary endpoint) was observed with rozanolixizumab, with a least square mean difference vs placebo of -3.5 points at the 7mg/kg dose and -4.8 points at the 10mg/kg dose (both doses P <.001).

The most common adverse reactions reported with rozanolixizumab were headache, infections, diarrhea, pyrexia, hypersensitivity reactions, and nausea.

Rystiggo is supplied in a 280mg/2mL single-dose vial. It is administered subcutaneously using an infusion pump. The product is expected to be available in the third quarter of 2023.