The review, “Effectiveness and safety of tacrolimus therapy for myasthenia gravis: A single arm meta-analysis” was published in the Journal of Clinical Neuroscience.
Prograf, which suppresses immune responses, was initially approved to prevent organ rejection after a transplant, and currently is used for a variety of indications, including autoimmune diseases such as lupus.
Because of its biological effects in limiting immune cell activation and antibody production as well as improving muscle strength, the drug has been proposed as a potential therapeutic option for MG as well.
Some clinical studies have supported its use, both for MG patients who do not respond to (refractory) or have an inadequate response to conventional treatment.
The two published randomized controlled trials (RCTs) (NCT00309088 and NCT01325571) that showed the superiority of Prograf therapy versus placebo, however, had limited data, with a small number of patients and short follow-up.
To more robustly analyze the evidence available on the efficacy and safety of this treatment for MG, researchers performed a grouped analysis, or meta-analysis, of several clinical trials evaluating the drug for MG.
A prior review by the same researchers looked at studies comparing a Prograf group with a control group. The results demonstrated a superior efficacy when adding the medicine to glucocorticoid therapy, compared with glucocorticoid therapy alone.
This time, researchers wanted to evaluate only the results of single-arm studies — clinical studies with a single group of patients — who were treated with oral Prograf.
After searching the literature, researchers identified 25 studies involving 633 patients, whose data they analyzed altogether. Mean treatment periods ranged from one to 39.6 months.
The results showed that patients taking Prograf had a 21% mean reduction in glucocorticoid dose, along with a significant reduction in patient-reported disease severity scores (QMG score) and symptoms (MG-ADL survey).
The treatment also led to a significant reduction in the serum concentration of anti-acetylcholine receptor (AChR) antibodies, typically increased in MG.
In terms of safety, adverse events were observed in 258 of the 633 patients (40.8%), most of them mild in severity. Common adverse events included gastrointestinal disturbances (4.4%), increased blood glucose level (4.3%), headache (2.8%), bone marrow suppression (2.5%), and a high level of fats in the blood (2.1%).
Researchers also noted a correlation between disease duration and the reduction of MG severity scores. Those who have been living with the disease for less time had greater reductions in MG severity when taking Prograf, “demonstrating that early intervention may improve the MG symptoms better, ” researchers stated. “Therefore, tacrolimus treatment should be supplemented in the early phase of disease. ”
The report states, “Our meta-analysis demonstrates that tacrolimus may be a beneficial drug option to treat MG.”
Researchers said the study provides evidence that “tacrolimus therapy exhibits a steroid-sparing effect” and can also “significantly reduce QMGS, MG-ADL and serum antiAChR antibody titer with improved symptoms.”