[Efficacy of Telitacicept combined with low-dose mycophenolate mofetil in the treatment of moderate-to-severe systemic lupus erythematosus].

<b>Objective:</b> To evaluate the efficacy of Telitacicept combined with low-dose mycophenolate mofetil (MMF, 1 g/day) in patients with moderate-to-severe systemic lupus erythematosus (SLE). <b>Methods:</b> In this prospective, open-label, randomized controlled trial, 84 patients with active SLE [Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K)≥10] were enrolled at Shanxi Provincial People's Hospital from June 2023 to June 2024. The participants were randomized to 2 groups with block randomization sequence: Telitacicept group (the patients were given subcutaneous Telitacicept 160 mg weekly+MMF 1 g/day+prednisone) and the MMF group (the patients were treated with MMF 2 g/day+prednisone). The primary endpoint was non-inferiority in SLEDAI-2K reduction at week 24 (margin Δ=2.0). The secondary endpoints included British Isles Lupus Assessment Group 2004 (BILAG-2004), Physician's Global Assessment (PGA), complement levels, glucocorticoid-tapering success rate (prednisone≤7.5 mg/d), and adverse events. <b>Results:</b> A total of 84 patients with moderate-to-severe SLE were enrolled, including 75 females (89.29%), with a mean age of (39.39±10.68) years. There were 43 cases in the Telitacicept group and 41 cases in the MMF group. The Telitacicept group demonstrated non-inferior SLEDAI-2K reduction [(14.77±5.28) vs (17.32±5.99) points, 95%<i>CI</i> of between-group difference:-1.92 to 0.43]. Compared to the MMF group, the Telitacicept group showed a significantly higher achievement rate of prednisone reduction to≤7.5 mg/d [83.72% (36/43) vs 63.41% (26/41), <i>P</i>=0.034], a lower incidence of infections [23.26% (10/43) vs 68.29% (28/41), <i>P</i><0.001], and a lower anti-dsDNA level [(64.87±44.11) vs (111.92±34.08) U/ml, <i>P</i>=0.001]. In the lupus nephritis subgroup, the 12-week urinary protein remission rate (<0.5 g/24 h) was 90.48% (19/21) in the Telitacicept group, it was higher than that in the MMF group [73.91% (17/23)](<i>P</i>=0.042). The Telitacicept group showed a greater improvement in complement C3 level [(1.03±0.35) vs (0.89±0.29) g/L, <i>P</i>=0.063]. No intergroup differences in BILAG-2004, PGA, or joint symptoms improvement was found between the two groups (all <i>P</i>>0.05). <b>Conclusion:</b> Telitacicept plus low-dose MMF shows comparable efficacy to high-dose MMF for moderate-to-severe SLE, with superior glucocorticoid sparing and reduced infection risk.