Tacrolimus found effective for most children with juvenile MG: Study
Off-label tacrolimus helps improve symptoms, reduce need for corticosteroids
Tacrolimus, an immunosuppressant sometimes used off-label to treat adults with myasthenia gravis (MG), eased symptoms of the disease in about four in every five children with juvenile MG, with few side effects.
That’s according to a meta-analysis of nine studies from China and Japan, which also found tacrolimus reduced the need for corticosteroids, often used when other treatments fail to keep MG symptoms under control. Corticosteroids, however, can cause serious side effects when taken for a long time or at a high dose.
Findings of the meta-analysis were detailed in a study, “Efficacy and safety of tacrolimus therapy in patients with juvenile myasthenia gravis: A single arm meta-analysis,” published in Pediatric Neurology.
MG is an autoimmune disease that occurs when the immune system mistakenly attacks proteins required for the communication between nerves and muscles involved in the body’s voluntary movements. As a result, muscles become weak and easily fatigued.
While evidence from clinical testing doesn’t support the use of tacrolimus for MG, the therapy is still widely used off-label. Guidelines continue to recommend tacrolimus or other immunosuppressants when first-line treatment with pyridostigmine (sold as Mestinon and generics) fails to control MG symptoms and corticosteroids are not an option.
Tacrolimus works to reduce activity of immune system
Tacrolimus, marketed under the brand name Prograf among others, works to reduce the activity of the immune system. While it appears safe and effective for adults with MG, not many studies have looked into its use in children.
To combine available data, researchers did a meta-analysis of nine studies involving a total of 313 children with juvenile MG. Two studies compared tacrolimus against corticosteroids, and seven evaluated how severe MG symptoms were before and after treatment with tacrolimus.
The meta-analysis revealed an 80% overall response rate, defined as the proportion of patients attaining remission, having minimal disease manifestations, or showing substantial improvements following treatment.
Seven of the studies reported changes in the use of corticosteroids. After treatment with tacrolimus, the children’s dose was reduced, and in one study, all 23 children who received tacrolimus discontinued treatment with corticosteroids.
The meta-analysis also revealed improvements in the scores of the MG Activities of Daily Living, a measure of MG severity that evaluates how disease symptoms interfere with everyday activities, and in Quantitative Myasthenia Gravis scores, another measure of disease severity.
While in some studies it wasn’t possible to confirm whether tacrolimus was used alone or in combination with other medications, and all were from Asian countries, these findings show tacrolimus may ease symptoms in most children with MG.
“Future studies with larger sample sizes should be conducted to explore the efficacy and safety of [tacrolimus] in patients worldwide,” the researchers wrote.
No serious side effects were reported with tacrolimus, suggesting it “may be a beneficial treatment option in patients with [juvenile MG],” the researchers wrote, noting the importance of informing patients and their families that tacrolimus use in MG and juvenile MG remains off-label.
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