Atlanta – October 16, 2026 -- The U.S. Food and Drug Administration (FDA) has approved a once-daily autoinjector for UCB's ZILBRYSQ (zilucoplan), with complete dose delivery in 99.8% of 449 administrations, UCB said. Commercial availability is expected in Q1 2027.
The device is cleared for adults with generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody positive. UCB (Euronext Brussels: UCB) describes ZILBRYSQ as the first and only macrocyclic peptide C5 inhibitor approved as a self-administered, once-daily subcutaneous autoinjector for gMG in the U.S.
Autoinjector adds a second self-administration route alongside the prefilled syringe
Before this approval, ZILBRYSQ was available only as a self-administered prefilled syringe (PFS). The autoinjector automatically delivers a pre-defined dose when activated against the skin. Patients or their care partners now have two portable options.
Donatello Crocetta, UCB's Global Head of Medical Affairs and Chief Medical Officer, said the company had to confirm that the added option did not come at the expense of safety and efficacy.
Three studies back the approval, including a bioequivalence trial in 14 volunteers
The Phase 1 DV0012 study, an open-label, single-center, two-period crossover trial in 14 healthy adult volunteers, established bioequivalence between the autoinjector and the PFS.
The Phase 3b DV0013 study enrolled 31 adults with gMG who self-administered ZILBRYSQ by autoinjector once daily. Complete dose delivery was achieved in 99.8% of 449 administrations, counted as total autoinjectors used and returned. Patients reported high satisfaction. Self-administration was generally well tolerated, and the most common treatment-emergent adverse event was injection-site pain, reported by 3 patients (9.7%).
A human factors validation study of 100 participants found that 90% completed an injection on their first attempt without training. Participants included gMG patients or people with ocular symptoms, caregivers and healthcare professionals, both injection-experienced and injection-naïve.
Boxed meningococcal warning and REMS restrictions remain in force
ZILBRYSQ carries a boxed warning for serious meningococcal infections, which have been life-threatening and fatal in patients treated with complement inhibitors. Patients should complete or update meningococcal vaccination for serogroups A, C, W, Y and B at least 2 weeks before the first dose, unless delaying therapy carries greater risk.
The drug is available only through the ZILBRYSQ Risk Evaluation and Mitigation Strategy (REMS) program, under which prescribers must enroll, counsel patients and ensure vaccination. It is contraindicated for initiation in patients with unresolved Neisseria meningitidis infection.
UCB now fields two approved gMG therapies with distinct mechanisms
UCB's gMG portfolio also includes RYSTIGGO (rozanolixizumab-noli), a subcutaneously infused monoclonal antibody targeting the neonatal Fc receptor (FcRn). The FDA has approved it for adults who are anti-AChR or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.