The Medicines and Healthcare products Regulatory Agency (MHRA) has approved UCB’s C5 inhibitor Zilbrysq (zilucoplan) as an add-on therapy for a subset of patients with generalised myasthenia gravis (gMG).
The marketing authorisation specifically applies to adults who are anti-acetylcholine receptor (AChR) antibody-positive.
In gMG, a rare autoimmune disease with a global prevalence of 100 to 350 cases per one million people, pathogenic autoantibodies target proteins in the neuromuscular junctions. This disrupts the ability of the nerves to stimulate the skeletal muscle and results in a weaker contraction.
Patients can experience a variety of symptoms, including severe muscular weakness that can result in double vision, drooping eyelids, difficulty swallowing, chewing and talking, and life-threatening weakness of the muscles of respiration.
UCB’s Zilbrysq, which is administered subcutaneously, inhibits complement-mediated damage to the neuromuscular junction through its targeted dual mechanism of action.
The MHRA’s decision was supported by positive results from the late-stage RAISE study, which demonstrated that Zilbrysq delivered “consistent, statistically significant and clinically meaningful” improvements in patient- and clinician-reported outcomes at week 12 in a broad population of adult patients with mild-to-severe anti-AChR antibody-positive gMG, UCB said.
Nadeem Aurangzeb, head of rare disease at UCB UK, said: “The approval of [Zilbrysq] for gMG is a significant milestone for the rare disease community in the UK… We are proud to deliver a new treatment option for adults living with this rare, life-limiting and debilitating condition.”
The approval comes less than two months after Zilbrysq was approved by the European Commission for the same patient population.
The EU regulator also approved UCB’s neonatal Fc receptor blocker Rystiggo (rozanolixizumab) earlier this month as an add-on therapy for adults with gMG who are anti-AChR or anti-muscle-specific tyrosine kinase antibody-positive.
This decision was based on results from the phase 3 MycarinG study, in which treatment with Rystiggo resulted in statistically significant improvements at day 43 in gMG-specific outcomes, including everyday activities such as breathing, talking, swallowing, and being able to rise from a chair.
Zilbrysq and Rystiggo have also been approved in the US and Japan for the treatment of certain adult patients with gMG.