The US Food and Drug Administration (FDA) has approved UCB’s Rystiggo (rozanolixizumab-noli) to treat certain patients with generalised myasthenia gravis (gMG), a rare autoimmune disease with a global prevalence of 100 to 350 cases per one million people.
The approval specifically applies to adults who are anti-acetylcholine receptor or anti-muscle-specific tyrosine kinase antibody positive, making Rystiggo the only FDA-approved treatment for both of these subtypes.
In gMG, autoantibodies target neuromuscular junction proteins. This disrupts the ability of the nerves to stimulate the muscle and results in weakness.
Patients can experience a variety of symptoms, including severe muscular weakness that can result in life-threatening weakness of the muscles of respiration, double vision, drooping eyelids, and difficulty swallowing, chewing and talking.
UCB’s Rystiggo, which is administered subcutaneously, is a humanised IgG4 monoclonal antibody that binds to the neonatal Fc receptor, resulting in a reduction of circulating IgG.
The FDA’s decision was supported by positive 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.
Lead investigator of the study, professor Vera Bril, explained: “People living with gMG often face treatment options that are broad-acting, and that have traditionally only offered symptomatic relief.
“There is a significant need for new, innovative treatment options to reduce the day-to-day burden of gMG. [Rystiggo] is a new treatment option, targeting one of the mechanisms of disease to provide symptom improvement in patient-and physician reported outcomes at day 43.”
Rystiggo will be commercially available in the US during the third quarter of this year, UCB outlined, adding that the treatment is also currently under review in the EU and Japan for adults with gMG.
“No two people living with gMG experience the disease in the same way, so we can’t take a ‘one size fits all’ approach to disease management,” said UCB’s executive vice-president and chief medical officer, Iris Loew-Friedrich.
“The [US] approval of [Rystiggo] means doctors have an additional approved treatment option for their gMG patients who have not yet found a treatment that meets their needs,” Loew-Friedrich added.