CD25 blockade in kidney transplant patients randomized to standard‐dose or high‐dose basiliximab with cyclosporine, or high‐dose basiliximab in a calcineurin inhibitor‐free regimen

Summary An increased basiliximab dose may saturate T-cell CD25 receptors in kidney transplant patients receiving calcineurin inhibitor (CNI)-free immunosuppression. In a 12-week study, 16 de novo kidney transplant patients were randomized to (i) 40 mg basiliximab with cyclosporine [n = 3] (controls), (ii) 80 mg basiliximab with cyclosporine [n = 6], or (iii) 80 mg basiliximab with everolimus (CNI-free) [n = 7], all with mycophenolic acid and steroids. Recruitment was stopped prematurely due to increased biopsy-proven acute rejection (BPAR) in the basiliximab 80 mg CNI-free group. BPAR occurred in 1/3, 1/6, and 4/7 patients in the three treatment groups, respectively. The primary endpoint, area under the effect curve of CD25 saturation to week 12, was 8.4(1.6) % × weeks in the control group, 11.1(1.1) % × weeks with basiliximab 80 mg + cyclosporine, and 9.7(0.7) % × weeks in the basiliximab 80 mg CNI-free group (P = 0.020 for basiliximab 80 mg + cyclosporine versus controls; P = 0.119 for basiliximab 80 mg CNI-free versus controls). Although small patient numbers prohibit robust conclusions, these results suggest that doubling the cumulative basiliximab dose to 80 mg does not provide adequate immunosuppression during the first 3 months after kidney transplantation in the absence of CNI therapy (ClinicalTrials.gov number: NCT01596062).