The U.S. Food and Drug Administration on Friday approved the first self-administered, once-daily autoinjector version of UCB SA (UCBJY) and (UCBJF) Zilbrysq (zilucoplan) for generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) antibody-positive.
Generalized myasthenia gravis is a rare autoimmune disease that affects 150 to 350 people per million worldwide. It causes muscle weakness, double vision, drooping eyelids, and difficulty swallowing, chewing or speaking. In severe cases, it can impair breathing.
Zilbrysq Autoinjector Approval Data
The Zilbrysq autoinjector automatically delivers a pre-defined dose when activated against the skin.
Before this approval, Zilbrysq was available as a self-administered prefilled syringe (PFS).
The FDA's approval of the autoinjector is supported by data from three studies.
DV0012, a Phase 1 study involving 14 healthy adult volunteers, established the bioequivalence of Zilbrysq delivered via an autoinjector compared to a PFS.
DV0013, a Phase 3b study in 31 adult patients with gMG, showed complete dose delivery in 99.8% of autoinjector administrations.
Patients reported high satisfaction with the device, and self-administration was generally well-tolerated.
The most common treatment-emergent adverse event was injection-site pain.
A human factors validation study involving 100 participants demonstrated that 90% completed an injection with the Zilbrysq autoinjector on their first attempt without training.
Commercial Availability and Portfolio
UCB anticipates the autoinjector will be commercially available in the first quarter of 2027.
Zilbrysq is a once-daily, self-administered subcutaneous injection that works by blocking complement component 5 (C5).
In addition to Zilbrysq, UCB's gMG portfolio includes RYSTIGGO (rozanolixizumab-noli), a subcutaneously infused monoclonal antibody targeting the neonatal Fc receptor (FcRn) approved by the FDA for gMG in adult patients who are anti-AChR or anti-muscle-specific tyrosine kinase (MuSK) antibody-positive.
