Zilbrysq Now Available in the United States as Treatment for Generalized Myasthenia Gravis
Zilbrysq (zilucoplan; UCB, Atlanta, GA), a treatment for generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor antibody positive (anti-AChR Ab+), is now available in the United States. Zilbrysq is the first approved once-daily subcutaneous, targeted complement component 5 (C5) inhibitor for gMG. The medication is available by prescription in pre-filled syringes that are self-administered on a once-daily basis.
Zilbrysq received Food and Drug Administration (FDA) approval in 2023 based on results from the RAISE study (NCT04115293), published in The Lancet Neurology. RAISE was a phase 3, multicenter, randomized, double-blind, placebo-controlled study that assessed the efficacy, safety, and tolerability of Zilbrysq as a treatment for 174 adult participants with a diagnosis of anti-AChR Ab+ gMG. After 12 weeks, participants in the Zilbrysq group (n=86) showed a greater reduction in the primary outcome measure of Myasthenia Gravis–Activities of Daily Living (MG-ADL) score, compared to those in the placebo group (n=88), with least squares mean difference of -2.09 (95% CI, -3.24 to -.95; P=.0004). Treatment with Zilbrysq was also associated with a significant reduction in Quantitative Myasthenia Gravis (QMG) score, compared to placebo.
The prescribing information for Zilbrysq contains a Boxed Warning for serious meningococcal infections. Due to this Boxed Warning, Zilbrysq is only available to health care providers who enroll in the Zilbrysq Risk Evaluation and Mitigation Strategies (REMS) program. Injection site reactions, upper respiratory tract infections, and diarrhea are the most common side effects of the medication.
Zilbrysq, along with Rystiggo (rozanolixizumab-noli; UCB, Atlanta, GA), is available through UCB’s ONWARD program, which provides personalized support to patients who use targeted treatments for gMG. ONWARD assists patients through access to a dedicated Care Coordinator, injection coaching, information on symptom tracking, and information about insurance coverage, along with other resources.