Tacrolimus shows clinical benefit in JMG

By Litha Mfiki

A meta-analysis reveals that tacrolimus, a drug traditionally used to treat myasthenia gravis (MG) in adults, significantly improves symptoms and MG-related scores in patients with juvenile MG (JMG), while causing minimal adverse effects.

Tacrolimus therefore “may be a successful treatment option in patients with JMG,” write Aidou Jiang (West China Hospital, Sichuan University, Chengdu) and colleagues in Pediatric Neurology.

The researchers analyzed nine trials involving 313 individuals with JMG. Two studies compared tacrolimus with corticosteroids, while the remaining seven measured participants’ progress before and after taking tacrolimus. All studies were conducted in Asian countries, primarily China and Japan.

The analysis, using a random-effects model, reported an overall response rate of 3.92 (95% CI, 2.06–7.45), corresponding to a definite responder rate of 80%.

Due to the absence of statistical heterogeneity, the researchers applied the same model to assess changes in MG-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores. Six trials showed a significant reduction in MG-ADL scores, while three reported significant improvements in QMG scores. Additionally, three studies found that tacrolimus significantly reduced serum acetylcholine receptor antibody titers.

MG-ADL scores improved as early as 1 month after initiating tacrolimus treatment, with continued improvement observed at 3, 6, and 12 months or longer.

Seven studies tracked changes in corticosteroid dosage to evaluate tacrolimus’s steroid-sparing effect. Analysis of the two that reported corticosteroid doses as mean values per kilogram of bodyweight per day revealed a significant reduction in corticosteroid dosage following treatment with tacrolimus.

Although four studies reported a total of 23 tacrolimus-related adverse drug reactions, none were serious. However, two studies noted adverse effects that led to treatment discontinuation in 13 patients.

The researchers acknowledge several limitations, including that some patients received additional, unrecorded treatments alongside tacrolimus, making it difficult to isolate the drug’s specific effects. Inconsistent reporting prevented the team from assessing the relationship between tacrolimus dosage and treatment efficacy. Missing demographic data, a limited number of studies, and incomplete adverse event reporting may have introduced bias and affected the reliability of the findings.