Treatment of myasthenia gravis patients with calcineurin inhibitors in Japan: A retrospective analysis of outcomes

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

Oral corticosteroid dosing regimen and long-term prognosis in generalised myasthenia gravis: a multicentre cross-sectional study in Japan

OBJECTIVE

We examined the correlation between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL ≤5 mg/day lasting >6 months (the treatment target) in patients with generalised myasthenia gravis (MG).

METHODS

We classified 590 patients with generalised MG into high-dose (n=237), intermediate-dose (n=187) and low-dose (n=166) groups based on the oral PSL dosing regimen, and compared the clinical characteristics, previous treatments other than PSL and prognosis between three groups. The effect of oral PSL dosing regimen on the achievement of the treatment target was followed for 3 years of treatment.

RESULTS

To achieve the treatment target, ORs for low-dose versus high-dose regimen were 10.4 (P<0.0001) after 1 year of treatment, 2.75 (P=0.007) after 2 years and 1.86 (P=0.15) after 3 years; and those for low-dose versus intermediate-dose regimen were 13.4 (P<0.0001) after 1 year, 3.99 (P=0.0003) after 2 years and 4.92 (P=0.0004) after 3 years. Early combined use of fast-acting treatment (OR: 2.19 after 2 years, P=0.02; OR: 2.11 after 3 years, P=0.04) or calcineurin inhibitors (OR: 2.09 after 2 years, P=0.03; OR: 2.36 after 3 years, P=0.02) was associated positively with achievement of treatment target.

CONCLUSION

A low-dose PSL regimen with early combination of other treatment options may ensure earlier achievement of the treatment target in generalised MG.

Efficacy and safety of tacrolimus for myasthenia gravis: a systematic review and meta-analysis

To evaluate the efficacy and safety of tacrolimus in patients with myasthenia gravis (MG), a systematic review and meta-analysis was performed. We searched PubMed and Embase for randomized controlled trials and clinical controlled trials in English language. Demographic and clinical characteristics of the MG patients were extracted. Differences in the current glucocorticoids (GC) dose in each included study were the primary outcome measure. The adverse events reported in each included study were used as safety evaluation. There were 5 trials included involving 683 patients. In this systematic review, we identified treatment with tacrolimus did not exhibit a statistically significant difference in the GC dose reduction at 6 months and 12 months compared with placebo. The standard mean differences in the GC dose reduction were -1.95 [(-4.20 to 0.30); p = 0.09] at 6 months and -1.72 [(-4.21 to 0.77); p = 0.18] at 12 months. But GC dose reduction from baseline in the tacrolimus group exceeded that in the controlled group. The weighted mean differences were -1.34 [(-2.46 to 0.23); p = 0.02] in the quantitative myasthenia gravis score and -1.10 [(-1.84 to -0.36); p = 0.004] in the myasthenia gravis activities of daily living score at 6 months. Adverse events were recorded in 80 of 347 patients (23%) treated with tacrolimus and most of them were mild. This meta-analysis proves that tacrolimus therapy is beneficial to improve clinical symptoms in MG patients. Tacrolimus may be a worthy therapy to relieve MG symptoms.