We evaluated the efficacy and safety of rituximab as induction therapy in renal transplant patients. In a double-blind, placebo-controlled study, 280 adult renal transplant patients were randomized between a single dose of rituximab (375 mg/m2) or placebo during transplant surgery. Patients were stratified according to panel-reactive antibody (PRA) value and rank number of transplantation. Maintenance immunosuppression consisted of tacrolimus, mycophenolate mofetil and steroids. The primary endpoint was the incidence of biopsy proven acute rejection (BPAR) within 6 months after transplantation. The incidence of BPAR was comparable between rituximab-treated (23/138, 16.7%) and placebo-treated patients (30/142, 21.2%, p = 0.25). Immunologically high-risk patients (PRA >6% or re-transplant) not receiving rituximab had a significantly higher incidence of rejection (13/34, 38.2%) compared to other treatment groups (rituximab-treated immunologically high-risk patients, and rituximab- or placebo-treated immunologically low-risk (PRA ≤ 6% or first transplant) patients (17.9%, 16.4% and 15.7%, p = 0.004). Neutropenia (<1.5 × 109/L) occurred more frequently in rituximab-treated patients (24.3% vs. 2.2%, p < 0.001). After 24 months, the cumulative incidence of infections and malignancies was comparable. A single dose of rituximab as induction therapy did not reduce the overall incidence of BPAR, but might be beneficial in immunologically high-risk patients. Treatment with rituximab was safe.
In a randomized clinical trial in renal transplantation, the authors show that a single dose of rituximab added to standard immunosuppressive therapy does not reduce the overall incidence of biopsy-proven allograft rejection, but seems beneficial in immunologically high-risk patients. See editorial by Clatworthy on page 297.