Rozanolixizumab May Safely Ease Symptom Severity in gMG Patients
Rozanolixizumab, UCB’s investigational antibody, may ease symptom severity in adults with generalized myasthenia gravis (MG), and help them carry on with daily activities, top-line data from the Phase 3 MycarinG study suggests.
Moreover, rozanolixizumab, given as an under-the-skin (subcutaneous) infusion, was found to be generally safe and well-tolerated.
The company now plans to present final data from the study next year and to seek approval, in the third quarter of 2022, from regulatory authorities in the U.S., Europe, and Japan for the use of rozanolixizumab for this indication.
“We are enthusiastic about these positive and clinically meaningful results, which mark a critical step forward for rozanolixizumab and UCB’s commitment to delivering differentiated solutions for people living with rare diseases, such as myasthenia gravis,” Iris Loew-Friedrich, MD, PhD, executive vice-president and chief medical officer at UCB, said in a press release.
Rozanolixizumab, also known as UCB7665, acts by binding to human neonatal Fc receptor or FcRn, a protein that plays a key role in recycling immunoglobulin G (IgG) antibodies and extending the time they remain in circulation in the bloodstream.
IgG antibodies are made by certain white blood cells to help the body fight infections. However, in people with MG, some IgG antibodies are self-reactive. This means that they are directed against some of the body’s own proteins, causing the typical symptoms of the disease.
Blocking FcRn is expected to reduce overall and disease-causing IgG levels. Indeed, in a previous Phase 2 study (NCT03052751), rozanolixizumab not only lowered IgG levels in circulation, but also eased symptom severity.
“Today’s encouraging findings from the MycarinG study show the potential of rozanolixizumab in the treatment of myasthenia gravis, and further reinforce the suggestion that FcRn inhibition may be a promising approach for this disease,” said Vera Bril, MD, professor of neurology at the University of Toronto, in Canada, and the study’s lead investigator.
The MycarinG study (NCT03971422), which completed patient recruitment earlier this year, was designed to test rozanolixizumab’s safety and efficacy in up to 200 adults with generalized MG. The trial examined how well rozanolixizumab worked, compared with a placebo, at alleviating disease symptoms.
Its primary goal was to evaluate score changes in the Myasthenia Gravis Activities of Daily Living Profile (MG-ADL), an eight-question, patient-filled survey that assesses the severity of symptoms and how they affect daily activities. The total MG-ADL score, ranging from 0 to 24, is obtained by summing the responses to each question. A higher score indicates more disability.
Patients who received rozanolixizumab attained a clinically meaningful change in MG-ADL from the beginning of the study to day 43 (about 1.5 months).
Secondary outcomes — response rates, changes in the MG Composite (MGC) and the Quantitative MG (QMG) score, and patient-reported outcomes — also were met.
An open-label extension study (NCT04650854) to assess the effects of rozanolixizumab for an additional six weeks is underway and is planned to conclude in 2023. The extension study is currently enrolling patients, including those who completed MycarinG, by invitation only.
UCB also is testing its investigational small molecule zilucoplan for the treatment of generalized MG in a Phase 3 study (NCT04115293) called RAISE, with preliminary results expected in the coming weeks.
“For the many thousands of people living with myasthenia gravis around the world, current treatment options can be very limited,” said Samantha Masterson, president and CEO of the Myasthenia Gravis Foundation of America (MGFA). “Given that this disease causes a wide range of symptoms, some of which can require urgent intervention or hospitalization, there is a critical need for new treatment options that could address the unmet needs of patients living with myasthenia gravis.”
For the moment, however, neither rozanolixizumab nor zilucoplan are approved for use in any indication.