The Medicines and Healthcare products Regulatory Agency (MRHA) has approved UCB’s Rystiggo (rozanolixizumab) to treat patients with generalised myasthenia gravis (gMG), a rare autoimmune disease with a global prevalence of 100 to 350 cases per one million people.
In gMG, immunoglobulin G (IgG) antibodies trigger the immune system to damage the communication between nerves and muscles.
Patients can experience a variety of symptoms, including severe muscular weakness that can result in double vision, drooping eyelids, difficulty swallowing, chewing and talking, as well as life-threatening weakness of the muscles of respiration.
UCB’s Rystiggo, which is administered as an infusion under the skin, is a humanised IgG4 monoclonal antibody that binds to the neonatal Fc receptor, resulting in a reduction of circulating IgG.
The MHRA’s approval of the therapy was supported by positive results from a clinical trial of 200 adults with moderate-to-severe myasthenia gravis who received a low or higher dose of Rystiggo or placebo.
After six weeks of treatment, patients treated with Rystiggo at either dose had a reduction of around 3.4 points in their myasthenia gravis specific activities of daily living scores, which measures the impact of the disease on patients’ daily activities. This is compared to a reduction of around 0.8 points for those in the placebo cohort.
Julian Beach, MHRA interim executive director, healthcare quality and access, said: “Patient safety is always our priority, which means enabling their access to high-quality, safe and effective medical products.
“We’re assured that the appropriate regulatory standards for the approval of this medicine have been met. As with all products, we will keep its safety under close review.”
The decision comes just one month after the European Commission approved Rystiggo for adults with gMG who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase antibody positive.
The EU regulator also recently approved UCB’s Zilbrysq (zilucoplan) as an add-on therapy for gMG in adult patients who are anti-AChR antibody-positive.
The marketing authorisation made Zilbrysq the first once-daily subcutaneous, targeted component 5 complement inhibitor for gMG and was based on results from the late-stage RAISE study, in which Zilbrysq delivered clinically meaningful and statistically significant 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.