Abstract Details

We previously reported zilucoplan sustained efficacy for up to 60 weeks of treatment, with a favorable safety profile in a broad population of adult patients with AChR Ab+ gMG. RAISE-XT is ongoing and further long-term data will enhance our understanding of the safety and efficacy of zilucoplan in adults with gMG.

To evaluate the long-term safety and efficacy of zilucoplan, a macrocyclic peptide complement component 5 inhibitor, up to 96 weeks in patients with acetylcholine receptor autoantibody-positive (AChR Ab+) generalized myasthenia gravis (gMG) in an interim analysis of RAISE-XT (NCT04225871).

RAISE-XT, a Phase 3, multicenter, open-label extension study, included patients with gMG who participated in randomized, double-blind, Phase 2 (NCT03315130) and Phase 3 (NCT04115293) zilucoplan studies. All patients self-administered daily subcutaneous injections of zilucoplan 0.3 mg/kg. The primary outcome was incidence of treatment-emergent adverse events (TEAEs). Key secondary outcomes included Myasthenia Gravis Activities of Daily Living (MG-ADL) score.

In total, 200 patients enrolled in RAISE-XT. At data cut-off (May 11, 2023), median (range) exposure to zilucoplan was 1.8 (0.11–5.1) years. TEAEs occurred in 191 (95.5%) patients and 71 (35.5%) experienced a serious TEAE. The most common TEAEs were COVID-19, occurring in 64 (32.0%) patients, and MG worsening, occurring in 58 (29.0%) patients. At Week 96 of zilucoplan treatment, patients achieved a mean (standard error [SE]) change in MG-ADL score from double-blind study baseline of –6.33 (0.49). For patients who switched from placebo to zilucoplan at the end of the double-blind studies, mean (SE) reduction from baseline in MG-ADL score was –7.83 (0.60).