The Food and Drug Administration (FDA) has accepted for Priority Review the Biologics License Application (BLA) for rozanolixizumab for the treatment of adults with generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

Rozanolixizumab is a humanized monoclonal antibody that binds with high affinity to human neonatal Fc receptor (FcRn). The investigational treatment is designed to block the interaction of FcRn and immunoglobulin G (IgG), accelerating the catabolism of antibodies and inducing the removal of pathogenic IgG autoantibodies. 

The BLA is supported by data from the phase 3 MycarinG study (ClinicalTrials.gov Identifier: NCT03971422), which enrolled 200 adult patients 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 led to significant improvement in the Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score at day 43, with a least square mean difference vs placebo of -2.59 points at the 7mg/kg dose and -2.62 points at the 10mg/kg dose (both doses P <.001). 

Additionally, compared with placebo, a greater proportion of patients treated with rozanolixizumab 7mg/kg and 10mg/kg achieved clinically meaningful reductions in key secondary endpoints, including a 2.0-point or greater improvement in MG-ADL (P <.001), a 3.0-point or greater improvement in Quantitative Myasthenia Gravis (QMG) scores and a 3.0-point or greater improvement in Myasthenia Gravis Composite (MGC) scores.

As for safety, the most frequently reported treatment-emergent adverse events (TEAEs) with rozanolixizumab were headache, diarrhea, pyrexia, and nausea, with most cases being mild to moderate in severity.

The Company expects to receive feedback from the FDA in the second quarter of 2023.

Reference

UCB announces rozanolixizumab BLA for the treatment of generalized myasthenia gravis filed with US FDA and designated for Priority Review. News release. UCB. Accessed January 6, 2023. https://www.prnewswire.com/news-releases/ucb-announces-rozanolixizumab-bla-for-the-treatment-of-generalized-myasthenia-gravis-filed-with-us-fda-and-designated-for-priority-review-301714932.html.