FDA to Review Zilucoplan for Generalized Myasthenia Gravis

Zilucoplan is a subcutaneous, self-administered, macrocyclic peptide inhibitor of complement component 5.

The Food and Drug Administration (FDA) has accepted the New Drug Application (NDA) for zilucoplan for the treatment of generalized myasthenia gravis (gMG) in adult patients who are acetylcholine receptor antibody positive (AChR-Ab+).

Zilucoplan is a macrocyclic peptide inhibitor of complement component 5 (C5), which binds to and inhibits the cleavage of C5 into C5a and C5b preventing 3 pathways of complement activation. The NDA is supported by data from the multicenter, randomized, double-blind, placebo-controlled phase 3 RAISE study (ClinicalTrials.gov Identifier: NCT04115293), which included 174 adults with gMG. Patients were randomly assigned 1:1 to receive zilucoplan or placebo subcutaneously once daily for 12 weeks. 

Treatment with zilucoplan was associated with clinically meaningful and statistically significant improvements in key gMG-specific outcomes compared with placebo. Zilucoplan met the primary endpoint demonstrating a placebo-corrected mean improvement of 2.09 points in the Myasthenia Gravis Activities of Daily Living score at week 12 (P <.001).

Zilucoplan also met all key secondary endpoints, including statistically significant improvements in the Quantitative Myasthenia Gravis score, Myasthenia Gravis Composite score, and Myasthenia Gravis – Quality of Life 15-item revised score.

“If approved, zilucoplan has the potential to address the unmet need for people with gMG by providing targeted improvements in signs and symptoms of gMG disease activity and severity,” said Iris Loew-Friedrich, Executive Vice-President and Chief Medical Officer at UCB. “A benefit of targeted treatment is that it may help reduce the adverse events that can be associated with non-specific immunosuppressive treatment of gMG.”

The rate of treatment-emergent adverse events was found to be comparable between the zilucoplan (76.7%) and placebo (70.5%) groups. The most commonly reported adverse events were injection site bruising, headache, and diarrhea. Patients who completed the 12 weeks of treatment were enrolled in an open-label extension study (RAISE-XT; ClinicalTrials.gov Identifier: NCT04225871).

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


UCB announces US FDA acceptance of new drug application and EMA MAA validation for zilucoplan for the treatment of generalized myasthenia gravis in adult patients. News release. UCB, Inc. Accessed November 14, 2022. https://www.prnewswire.com/news-releases/ucb-announces-us-fda-acceptance-of-new-drug-application-and-ema-maa-validation-for-zilucoplan-for-the-treatment-of-generalized-myasthenia-gravis-in-adult-patients-301676223.html