Tacrolimus for children with refractory nephrotic syndrome: a one-year prospective, multicenter, and open-label study of Tacrobell®, a generic formula

Background: Cyclosporine A and tacrolimus (TAC) are often used as a second-line treatment for children with refractory nephrotic syndrome (NS). This study was undertaken to investigate the efficacy and safety of Tacrobell (R), a locally produced generic form of TAC. Methods: This study was a one-year prospective, open-label, single-arm, multicenter trial. Fourty-four children with steroid-dependent NS (SDNS) and 33 children with steroid-resistant NS (SRNS) were enrolled. The primary endpoints were defined as the remission rates, whereas the secondary endpoints were recognized as the duration of remission and adverse effects of TAC. Results: After one-year treatment, 34 (77.3%) of the 44 patients with SDNS were in complete remission, and 6 (13.6%) were in partial remission. Nineteen (43.2%) patients did not relapse during the study; for those who did relapse, the mean duration of remission was 4.6 +/- 2.9 months. The number of relapse episodes during the study period (0.90 per patient-year) was significantly lower than that in the preceding year (2.8 per patient year). After treatment for 3 and 6 months, 12 (36.4%) of the 33 patients with SRNS were in remission, and after treatment for 12 months, the number of patients had increased to 13 (39.4%). The mean time to achieve remission was 4.0 +/- 3.2 months. After remission (duration, 3.7 +/- 2.7 months), 12 (54.5%) of 22 patients relapsed. The fasting blood glucose and blood pressure levels during the therapy were similar to those at the time of study entry. Conclusions: Treatment with Tacrobell (R) was effective and safe for children with refractory NS. The efficacy of this generic form of TAC was better than that of the original TAC formula.