Ra Pharmaceuticals announces dosing of first patient in phase III pivotal study of zilucoplan for generalized myasthenia gravis.

Ra Pharmaceuticals, Inc. announced the initiation of dosing in the RAISE study, its global, pivotal, Phase III clinical trial evaluating zilucoplan for the treatment of generalized myasthenia gravis (gMG). The single, pivotal, randomized, double-blind, placebo-controlled Phase III trial is designed to evaluate the efficacy of a once-daily, subcutaneously (SC) self-administered dose of 0.3 mg/kg of zilucoplan versus placebo.

The trial is expected to enroll approximately 130 patients with gMG who are acetylcholine receptor (AChR)-antibody-positive, regardless of their prior therapies. The primary endpoint is the change in the MG Activities of Daily Living (MG-ADL) score from baseline to week 12. Following completion of the Phase III clinical trial, patients will have the option to enroll in the RAISE-XT study, an open-label, long-term extension study. Top-line results from this Phase III trial are expected in early 2021.

The initiation of the Phase III gMG clinical trial follows the successful completion of a Phase II, multi-center, randomized, double-blind, placebo-controlled clinical trial evaluating zilucoplan for the treatment of gMG. Rapid, clinically meaningful, and statistically significant improvements in the pre-specified primary and key secondary endpoints were observed for both zilucoplan dose groups tested versus placebo at 12 weeks. Treatment with zilucoplan was well-tolerated in the study, consistent with results observed in the previously-completed Phase 1 and Phase II studies. The majority of adverse events (AEs) reported were mild and were not considered by the investigators to be related to study drug. There were no serious AEs observed related to treatment with zilucoplan..