Background: Intravenous cyclophosphamide with prednisone is an effective treatment for lupus nephritis, but with significant toxicities. We compared the efficacy and safety of tacrolimus versus intravenous cyclophosphamide as induction therapy.

Study design: Multicenter noninferiority randomized controlled trial.

Setting & participants: 81 patients with biopsy-proven lupus nephritis from 9 nephrology centers in China from 2006-2008.

Intervention: Prednisone and either tacrolimus (n = 42) or intravenous cyclophosphamide (n = 39) for 6 months. Tacrolimus was started at 0.05 mg/kg/d and titrated to achieve a trough blood concentration of 5-10 ng/mL. Intravenous cyclophosphamide was initiated at 750 mg/m² of body surface area, then adjusted to 500-1,000 mg/m² every 4 weeks for a total of 6 pulse treatments.

Outcomes & measurements: The primary outcome was complete remission (proteinuria with protein excretion <0.3 g/24 h, serum albumin ≥3.5 g/dL, normal urinary sediment, and normal or stable serum creatinine level) at 6 months. Response (complete or partial remission), clinical parameters, and adverse effects were secondary end points.

Results: After the 6-month induction therapy, the tacrolimus group achieved higher cumulative probabilities of complete remission and response (52.4% vs 38.5% and 90.5% vs 82.1%, respectively) than the intravenous cyclophosphamide group, but differences were not statistically significant (log-rank test, P = 0.2 and P = 0.7, respectively). Proteinuria [corrected] was significantly decreased in tacrolimus- versus intravenous cyclophosphamide-treated patients after the first month of treatment, even with adjustment for baseline proteinuria (protein excretion, 1.76 vs 2.40 g/d; P = 0.02 for the log-transformed analysis). [corrected] After treatment, serum creatinine levels and estimated glomerular filtration rates were not significantly different between treatment groups. Adverse effects, such as leukopenia and gastrointestinal symptoms, were less frequent in the tacrolimus group.

Limitations: Nonblinded, small sample size, and short duration of follow-up.

Conclusions: In conjunction with prednisone, induction therapy with tacrolimus is at least as efficacious as intravenous cyclophosphamide and prednisone in producing complete remission of lupus nephritis and has a more favorable safety profile.