The research, “Immunosuppressive and monoclonal antibody treatment for myasthenia gravis: A network meta‐analysis,” was published in the journal CNS Neuroscience & Therapeutics.
Immunosuppressive treatment with glucocorticoids and azathioprine are first-line therapies in MG despite insufficient data on their effectiveness. Monoclonal antibodies such as Alexion’s Soliris and rituximab — marketed as Rituxan (by Genentech and Biogen) in the U.S., and MabThera (by Roche) in Europe — have been used increasingly and have shown positive results in severe generalized MG.
Although assessments of the effectiveness and safety of MG treatments have been conducted, no study has compared the different immunotherapies. As such, a team at Fudan University in China conducted a meta‐analysis — a type of statistical study combining the results of various studies — to address this gap and rank strategies for MG treatment.
Fourteen studies were included. Different parameters were assessed in a total of 808 MG patients, representing “the most comprehensive data analysis for current immunotherapies for MG,” the scientists commented. Treatment effectiveness was assessed via the quantitative MG score (QMGS), which was the primary goal. Secondary goals included steroid-sparing effect, as measured by glucocorticoid reduction, and therapy-related adverse events (AEs, aka side effects).
Among the analyzed patients, 245 of 769 who were assessed underwent thymectomy, and 48 out of 390 had a thymoma (a tumor in the thymus). Also, 684 of 725 patients (94.3%) had anti-acetylcholine receptor antibodies. The median follow‐up time was 7.5 months, range three to 36 months.
The effectiveness results revealed cyclosporine A (CsA) significantly outperformed placebo, CellCept (mycophenolate mofetil), by Genentech), and Prograf (tacrolimus, by Astellas), although Soliris and Prograf also showed significant benefits over placebo. Cyclophosphamide provided an improvement in muscle strength. When accounting for the follow-up period, Soliris and cyclophosphamide A provided significant benefits over placebo in QMGS.
Compared to placebo, only treatment with azathioprine over three years provided a significant reduction in glucocorticoids.
As for safety, while Benlysta and Soliris were associated with the least amount of AEs, treatment with cyclosporine A ranked last, as it induced the highest number of AEs.
“Our findings concluded that [Soliris] could be the most efficacious strategy for MG treatment with minor AEs,” the scientists wrote. Prograf “may be a beneficial therapy to treat MG,” they added, while the effectiveness of cyclosporine A and cyclophosphamide “may be limited by their AEs.”
Of note, the lack of randomized clinical trials precluded the inclusion of Rituxan in the analysis, the team noted. Also, determination of severe AEs could not be performed. An additional limitation was the studies’ differing inclusion criteria and treatment duration.