Patients with generalized myasthenia gravis (gMG) who were treated with rozanolixizumab (Rystiggo) in the phase III MycarinG clinical trial experienced sustained responses over multiple cycles of treatment, according to extension data presented by Dr. Robert Pascuzzi. The study found that patients with anti-acetylcholine receptor (AChR)-positive gMG who received higher doses of rozanolixizumab saw a continuous reduction in Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores. This promising data suggests that rozanolixizumab could be an effective long-term treatment option for gMG patients.
Maintained Benefit Across Subgroups
The study demonstrated that the benefits of rozanolixizumab treatment observed in the MycarinG trial were maintained for at least 6 to 12 months in patients across various subgroups. These subgroups included patients with different autoantibody status (AChR vs. anti-muscle-specific tyrosine kinase [MuSK] antibodies), duration of disease, age, thymectomy status, and baseline MG-ADL score. The consistent responses to the drug among these subgroups signify the potential of rozanolixizumab as a reliable treatment option for a wide range of gMG patients.
The main report of the MycarinG trial revealed that rozanolixizumab, at both 7 mg/kg and 10 mg/kg doses, significantly improved patient-reported and investigator-assessed outcomes in gMG patients. Based on these findings, the FDA approved rozanolixizumab for adults with gMG, making it the first drug to receive approval for both AChR and MuSK antibody-positive gMG subtypes. Dr. Pascuzzi emphasized that this study supports the use of rozanolixizumab in patients with gMG, particularly for those with MuSK antibody disease, as it is the only approved drug for this subtype.
Consistent Responses Among Subgroups
The similar responses to rozanolixizumab across different subgroups were not unexpected, according to Dr. Thomas Ragole. He explained that previous clinical trials for rozanolixizumab and similar drugs did not reveal significant variations in response rates among different patient groups. This consistency in the disease response suggests that rozanolixizumab effectively reduces the antibodies responsible for gMG, regardless of subgroup characteristics. However, Dr. Ragole notes that the magnitude of the drug’s effect may vary among different subgroups.
Each cycle of rozanolixizumab treatment consists of six weekly subcutaneous infusions. When the treatment’s effects begin to diminish, another cycle is initiated to maintain the patient’s improvements. Dr. Pascuzzi mentioned that, on average, patients require four treatment cycles per year. However, the specific treatment duration can vary depending on individual patient needs.
The study included 152 patients with at least 6 months of exposure to rozanolixizumab and 109 patients with at least 12 months of exposure to the drug. These patients were adults diagnosed with gMG and eligible for immunoglobulin or plasma exchange therapies. The data demonstrated that patients maintained their improvements in gMG symptoms for over a year.
The extension data from the MycarinG trial indicates that rozanolixizumab is a viable long-term treatment option for patients with gMG. The sustained responses observed across different subgroups highlight the drug’s efficacy and potential to improve patient outcomes. With the FDA’s approval, rozanolixizumab provides hope for individuals suffering from gMG, particularly those with MuSK antibody disease. Future research and clinical practice will continue to explore the full potential of rozanolixizumab in treating this debilitating condition.