Comparison between mono-tacrolimus and mono-prednisone in the treatment of ocular myasthenia gravis: a retrospective, observational cohort study

Objective The use of tacrolimus (TAC) in ocular myasthenia gravis (OMG) is generally reserved for cases refractory to prednisone (PRED); however, the advantage of monotherapy with tacrolimus (mono-TAC) over monotherapy with PRED (mono-PRED) remains unknown. The present study aimed to compare the efficacy and safety of mono-TAC and mono-PRED in OMG. Methods This single-center, retrospective study analyzed collected data from adult patients with treatment-naive newly diagnosed OMG who received either mono-TAC or mono-PRED. The primary outcome was the time to reach minimum symptom expression (MSE, defined as MG-ADL ≤ 1), with time to MG-ADL score of 0 as an exploratory endpoint. Secondary outcomes included the mean changes in Myasthenia Gravis Activities of Daily Living (MG-ADL) and ocular Quantitative Myasthenia Gravis (O-QMG) scores from baseline to months 1, 6, and 12 after treatment, respectively, as well as the monotherapy retention rates at month 12 in the two groups. Safety was assessed based on medical records during the hospitalization to monitor the adverse events. Results Forty-two patients were enrolled (mono-TAC: n = 27; mono-PRED: n = 15). For the primary outcome, the median time to MSE was 6.0 months (95% CI: 2.523-9.477) for PRED vs. 12.0 months (95% CI: 8.342-15.658) for TAC, with no significant difference between groups (log-rank P = 0.253). The exploratory endpoint of MG-ADL = 0 also showed comparable results between groups (P = 0.928). Secondary outcomes showed no significant differences in the mean changes in MG-ADL and O-QMG scores from baseline to 1, 6, and 12 months post-treatment (all P > 0.05). The monotherapy retention rates were similar (TAC: 81.5% vs. PRED: 73.3%, P = 0.698). Both treatments showed favorable safety profiles. Conclusion In conclusion, no statistically significant difference was observed in treatment response between tacrolimus and prednisone.