Effectiveness and safety of tacrolimus in systemic lupus erythematosus with various clinical manifestations: a retrospective real-world study

This study evaluated the real-world effectiveness and safety of tacrolimus as a steroid-sparing maintenance therapy alone without additional biologics or immunosuppressive medications in systemic lupus erythematosus (SLE), particularly in mild, non–new-onset cases, with a focus on glucocorticoid-sparing effects and multi-organ remission. A retrospective analysis was conducted using data from 679 SLE patients in the Chinese SLE Treatment and Research Group (CSTAR) cohort. Patients received tacrolimus for ≥ 4 weeks alongside glucocorticoids and/or hydroxychloroquine were included. Patients on other immunosuppressants or biologics at baseline were excluded. The primary endpoint was the changes in SLE Disease Activity Index 2000 (SLEDAI-2 K). Secondary endpoints included SLE Responder Index-4 (SRI-4) response at weeks 4, 24, and 48 (≥ 4-point SLEDAI-2 K reduction with no new major flare), Physician Global Assessment (PGA) scores, remission of organ-specific disease manifestations, reduction in daily glucocorticoid dose, and safety. At baseline, 84.39% (573/679) of patients had mild disease (SLEDAI-2 K ≤ 6), 11.49% (78/679) moderate, and 4.12% (28/679) severe. Statistically significant reductions in SLEDAI-2 K (baseline: 3.3 ± 4.1; week 48: 1.7 ± 2.2, p < 0.001) and PGA scores (p < 0.001) were observed. Glucocorticoid doses significantly decreased from 20.0 ± 18.3 mg/day (baseline, n = 590) to 10.0 ± 9.9 mg/day (week 48, n = 233; p < 0.001). SRI-4 response rates were 59.06% (75/127), 49.15% (58/118), and 48.75% (39/80) at weeks 4, 24, and 48, respectively. Organ remission rates ≥ 50% were achieved for mucocutaneous (78.95% [45/57]), serositis (88.89% [8/9]), arthritis (82.61% [19/23]), and leukopenia (71.87% [23/32]). Adverse events occurred in 7.36% (50/679) of patients, with only 0.74% (5/679) deemed treatment-related; serious AEs were rare (n = 3, none treatment-related). Tacrolimus demonstrated effectiveness in reducing disease activity, enabling significant glucocorticoid tapering, and inducing multi-organ remission in extrarenal manifestations. Its favorable safety profile supports its use as a promising sparing maintenance therapy alone, potentially obviating the need for additional biologic or immunosuppressive agents in SLE.