Clinical efficacy and safety of sirolimus in systemic lupus erythematosus: a real-world study and meta-analysis

Objective: To provide real-world data and summarize current clinical evidence on the efficacy and safety of sirolimus in active systemic lupus erythematosus (SLE) patients. Methods: This was a prospective real-world clinical study. Included SLE patients should have Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) > 2. They were treated with sirolimus and followed up regularly. The SLEDAI-2K, Physician Global Assessment (PGA), serological activity indices, and remission of organ manifestations were evaluated. We also performed a meta-analysis to integrate current evidence of sirolimus in SLE. Results: A total of 49 patients were included in the final analysis. After treatment, the SLEDAI-2K (6.2 +/- 3.1versus4.0 +/- 3.4, p = 0.001) decreased significantly, and the prednisone dosage was tapered successfully (9.9 +/- 8.8 mg/dayversus5.9 +/- 4.0 mg/day, p = 0.002). Serological activity indices also improved [complement 3 (C3): 0.690 +/- 0.209 g/lversus 0.884 +/- 0.219 g/l, p < 0.001; complement 4: 0.105 +/- 0.059 g/lversus 0.141 +/- 0.069 g/l, p < 0.001; anti-dsDNA antibody, 200 +/- 178 IU/mlversus156 +/- 163 IU/ml, p = 0.022]. The remission proportions of arthritis, skin rash, and thrombocytopenia were 100%, 88.8%, and 46.2%, respectively. A total of 41.2% of lupus nephritis (LN) patients achieved renal remission, but the average 24-h urine protein level was not significantly changed. Meta-analysis enrolled five studies with 149 patients included, and revealed similar results regarding the changes of SLEDAI-2K [-3.5 (-5.0, -2.1)], C3 [0.224 (0.136, 0.311) g/l] and daily dosage of prednisone [-12.7 (-19.9, -5.6) mg/day]. Conclusion: Sirolimus might be effective and tolerated in SLE. The role of sirolimus in LN requires further study.