Tacrolimus Appears Safe, Effective for Drug-Naïve Myasthenia Gravis

Neuromuscular Junction – 3d rendered image shown neuromuscular junction, where nerve end splits into several neural end plates on different muscle cells.
Investigators assessed the safety and efficacy of tacrolimus monotherapy as an initial approach for patients with drug-naïve myasthenia gravis.

Tacrolimus monotherapy appears to be a safe and effective initial approach to drug-naïve myasthenia gravis (MG), according to study results published in Neuromuscular Disorders.

In this study, a total of 14 drug-naïve patients with MG received tacrolimus alone, including 5 cases that underwent subsequent thymectomy. Throughout the study, the investigators allowed certain patients to use additional aggressive immunosuppressive therapies, including patients without thymectomy who did not experience a minimal manifestation (MM) or better status following 3 weeks of tacrolimus and patients with thymectomy who did not experience MM or better by 1 to 2 weeks following operation.

The median age of patients at disease onset was 66.5 years, and the median disease duration among patients prior to starting tacrolimus was 11 months. Approximately 57% (n=8) of the patients with generalized MG achieved MM or better status by the time of their first evaluation, while the remaining 43% (n=6) of patients who did not reach this endpoint at this time did so following 1 course of aggressive immunosuppressive treatment.

At 6 months, the study investigators observed significantly decreased MG scores (P =.001), MG-Activities of Daily Living scales (P =.001), and antiacetylcholine receptor antibody levels with tacrolimus.

By the end of the follow-up period, which ranged between 41 and 70 months, all patients in this study achieved the MM or better status. At the time of the analysis, none of the patients had severe adverse effects associated with treatment.

Limitations of this study included its single-center design, the lack of a control group, the small sample size, and the lack of a standardized protocol for the selection of the aggressive therapies.

Based on their experience, the study investigators concluded that “tacrolimus monotherapy as initial therapy appeared to be a safe and effective treatment for immunosuppressive drug-naïve patients with [antiacetylcholine receptor] positive [ocular MG] or [generalized MG].” “However,” they added, “in some MG patients with higher scores, additional rapid-acting immunotherapies were required to achieve early MM or better status.”


Itani K, Nakamura M, Wate R, et al.  Efficacy and safety of tacrolimus as long-term monotherapy for myasthenia gravis. Neuromuscul Disord. Published online February 22, 2021. doi:10.1016/j.nmd.2021.02.010