Symptoms of gMG controlled after switch from azathioprine to MMF
Researchers analyzed data from patients at 3 clinical centers from 2011 to 2024
Mycophenolate mofetil (MMF) safely and effectively controlled symptoms of generalized myasthenia gravis (gMG) in patients switching from azathioprine, another immunosuppressive agent, a study finds.
“This study supports the efficacy and safety of MMF in the treatment of MG,” wrote the study’s researchers, who said more research with a larger number of patients is needed “to validate these findings and further clarify the long-term efficacy and safety of MMF in MG.”
The study, “Effectiveness and Safety of Mycophenolate Mophetil in Myasthenia Gravis: A Real-Life Multicenter Experience” was published in Brain Sciences.
Myasthenia gravis (MG) is an autoimmune disease driven by self-reactive antibodies that disrupt nerve-muscle communication by targeting proteins such as acetylcholine receptors (AChRs) and muscle-specific kinase (MuSK) that play a key role in that process.
Immunosuppressants, which work broadly to suppress the activity of the immune system, are one of many types of medications to manage MG in the long term.
MMF, available commercially as CellCept, is an immunosuppressive agent that’s often used to prevent organ transplant rejection. It’s also shown potential at managing MG “due to its lower risk of serious organ toxicity and lower incidence of late-induced malignancies compared to others immunosuppressive therapies.” the researchers wrote.
Evaluating MMF safety, efficacy after switching from azathioprine
Using MMF for MG is supported by clinical experience, but still requires validation, “particularly regarding its speed of action, long-term efficacy, and safety profile,” wrote the researchers, who analyzed data from gMG patients treated with MMF at three Italian clinical centers from January 2011 to February 2024.
The study evaluated the efficacy of MMF, given alone or with corticosteroids and other treatments, in 32 gMG patients switching from azathioprine, another immunosuppressant sold as Imuran and other brand names.
Clinical efficacy was evaluated based on changes in the scores of two scales used to assess MG symptom severity: the MG Activities of Daily Living (MG-ADL) and the MG Composite Score (MGCS). Scores were assessed at the time of the switch, or baseline, and every six months thereafter for two years.
The patients had a mean age of 66.5 and 40% were men. Most (81%) were positive for anti-AChR antibodies, while 6% were positive for anti-MuSK antibodies. The remaining 13% were negative for both types of self-reactive antibodies. Most patients were receiving the corticosteroid prednisone (88%) and the acetylcholinesterase inhibitor pyridostigmine (sold as Mestinon) (88%) alongside MMF.
Significant improvements, that is, reductions, in MG-ADL and MGCS scores were seen at six and 12 months, and were sustained over two years. MG-ADL scores dropped from a mean of 6.4 at baseline to 5.1 at six months, and to 4.8 at 12 months. MGCS scores decreased from a mean of 7.6 at baseline to 6.2 at six months, and to 5.8 at 12 months.
Statistical analyses also showed switching to MMF was correlated with improvements in MG-ADL and MGCS scores at six and 12 months, “indicating the efficacy of MMF in managing MG symptoms,” the researchers wrote.
Four patients had side effects. Two had elevated levels of liver enzymes, which may indicate liver inflammation or damage, one had anemia, and another had diarrhea.
“While these effects are typically less severe than those associated with other immunosuppressants, they can still impact the patient’s quality of life and may require dose adjustments or additional medications to manage symptoms,” wrote the researchers, who said the findings are consistent with other studies that show MMF generally has a more favorable safety profile over immunosuppressants like azathioprine. They also said the findings demonstrated MMF’s ability to rapidly ease gMG symptoms, with significant improvements observed within six months after going off azathioprine, which is “particularly relevant considering that [azathioprine] often requires a longer period to achieve therapeutic effects.”
Overall, “these findings suggest that MMF is an effective and well-tolerated treatment option for patients with MG, offering faster symptom control and a good safety profile,” the researchers wrote.
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