Use of De Novo mTOR Inhibitors in Hypersensitized Kidney Transplant Recipients: Experience From Clinical Practice.

BACKGROUND: It is commonly believed that mTOR inhibitors (mTORi) should not be used in high-immunological risk kidney transplant recipients due to a perceived increased risk of rejection. However, almost all trials that examined the association of optimal-dose mTORi with calcineurin inhibitor (CNI) have excluded hypersensitized recipients from enrollment. METHODS: To shed light on this issue, we examined 71 consecutive patients with a baseline calculated panel reactive antibody (cPRA) ≥50% that underwent kidney transplantation from June 2013 to December 2016 in our unit. Immunosuppression was based on CNI (tacrolimus), steroids and alternatively mycophenolic acid (MPA; n = 38), or mTORi (either everolimus or sirolimus, n = 33, target trough levels 3-8 ng/mL). RESULTS: Demographic and immunological risk profiles were similar, and almost 90% of patients in both groups received induction with lymphocyte-depleting agents. Cox-regression analysis of rejection-free survival revealed better results for mTORi versus MPA in terms of biopsy-proven acute rejection (hazard ratio [confidence interval], 0.32 [0.11-0.90], P = 0.031 at univariable analysis and 0.34 [0.11-0.95], P = 0.040 at multivariable analysis). There were no differences in 1-year renal function, Banff chronicity score at 3- and 12-month protocol biopsy and development of de novo donor-specific antibodies. Tacrolimus trough levels along the first year were not different between groups (12-mo levels were 8.72 ± 2.93 and 7.85 ± 3.07 ng/mL for MPA and mTORi group respectively, P = 0.277). CONCLUSIONS: This single-center retrospective cohort analysis suggests that in hypersensitized kidney transplant recipients receiving tacrolimus-based immunosuppressive therapy similar clinical outcomes may be obtained using mTOR inhibitors compared to mycophenolate.

Combination of calcineurin and mTOR inhibitors in kidney transplantation: a propensity score analysis based on current clinical practice.

INTRODUCTION: The TRANSFORM study demonstrated that an immunosuppression based on a combination of calcineurin inhibitors and de-novo mTOR inhibitors (mTORi) is safe and effective in kidney transplant recipients. However, data that validate this approach in clinical practice are currently missing. MATERIALS AND METHODS: Analysis of 401 kidney transplant recipients transplanted from June 2013 to December 2016. All patients received tacrolimus with prednisone in combination with either mycophenolate (n = 186) or mTORi (either everolimus or sirolimus, n = 215). A propensity score to receive mTORi was calculated based on the inverse probability of treatment weighting (IPTW) from the following parameters: age and sex of donor and recipient, BMI, previous transplants, diabetes, cPRA, dialysis before transplantation, dialysis vintage, type of donor, ABO-incompatibility, HLA-mismatches, induction and ischemia time. Median follow-up was 2.6 [1.9; 3.7] years. RESULTS: Cox-regression analysis suggests good results for mTORi versus MPA in terms of 1-year biopsy-proven acute rejection (BPAR, P = 0.063), 1-year graft loss (P = 0.025) and patient survival (P < 0.001). Results observed for BPAR and graft failure were largely attributed to those patients that would have been excluded by the TRANSFORM because of some exclusion criteria (52.9% of the population, P = 0.003 for 1-year BPAR and P = 0.040 for graft loss). In patients who met selection criteria for TRANSFORM, no effect of treatment for BPAR or graft failure was observed, while the beneficial effect on overall survival persisted. CONCLUSIONS: In a real-life setting, a protocol based on de-novo mTORi with tacrolimus and prednisone could be employed as a standard immunosuppressive regimen and was associated with good outcomes.

Pre-implantation analysis of kidney biopsies from expanded criteria donors: testing the accuracy of frozen section technique and the adequacy of their assessment by on-call pathologists.

Pre-implantation renal biopsies of expanded criteria donors are one of the criteria used for allocation decisions, but there are concerns about the impact of the interobserver variability and the technique to be used. The aim was (i) to compare the original report performed by on-call pathologists using frozen sections (FS) to a retrospective analysis carried out by a trained pathologist using the same frozen section, and (ii) to compare the same FS to subsequently obtained paraffin sections (PS) by the same pathologist. A total of 92 biopsies, 78 from transplanted and 14 from nontransplanted cases, were analyzed. Agreement between observers using the same FS was weaker than the correlation between FS and PS in all the examined parameters (Kendall's Tau b for the Remuzzi score 0.104 vs. 0.306). According to the Remuzzi score, the revised FS analysis would have resulted in a higher rate of organ discard (n = 19) than PS (n = 14) and the original report (n = 6). However, kidneys that would have been discarded according to the retrospective analysis showed adequate outcomes in terms of graft survival and function. Accordingly, the impact of interobserver and technique-related variability can be minimized by the use of a relatively low threshold (RS ≤ 4) for organ acceptance.

Enteric-coated mycophenolate sodium immunosuppression in renal transplant patients: efficacy and dosing.

Mycophenolate mofetil (MMF), a mycophenolic acid (MPA) formulation, has improved both short- and long-term outcomes following renal transplantation, but is often associated with gastrointestinal (GI) complications that can lead to dose reduction or discontinuation, potentially jeopardizing patient outcomes. Enteric-coated mycophenolate sodium (EC-MPS) delivers equivalent MPA exposure to MMF and offers the potential to reduce GI burden (while maintaining patient safety). Here we review the efficacy of EC-MPS compared with MMF in renal transplant patients in terms of biopsy-proven acute rejection and graft loss, and examine the use of EC-MPS in newer regimens such as intensified dosing and calcineurin inhibitor minimization.

Efficacy and safety of enteric-coated mycophenolate sodium in renal transplant patients with diabetes mellitus: post hoc analyses from three clinical trials.

To examine the efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS, myfortic) in renal transplant patients with diabetes mellitus, six- and 12-month data from three clinical trials with EC-MPS (Studies B301, B302, and myPROMS) were analyzed post hoc. Studies B301 (de novo patients) and B302 (maintenance patients) followed a randomized double-blind design whereas myPROMS was an open-label study in de novo and maintenance renal transplant patients in which all patients received EC-MPS as part of their immunosuppressive regimen. In studies B301 and B302, diabetic patients were compared against mycophenolate mofetil (MMF, CellCept), the reference drug. For myPROMS, data from diabetic and non-diabetic patients were compared. In total, 246 diabetic patients receiving EC-MPS were analyzed. In study B301, the efficacy failure rate [biopsy-proven acute rejection (BPAR), graft loss, death or loss to follow-up] in diabetics at 12 months was 17.6% (EC-MPS) vs. 26.2% (MMF), and of BPAR alone 14.7% vs. 19.0% (both n.s.). In de novo patients from myPROMS, the treatment failure rate was similar in diabetic (20.3%) and non-diabetic patients (27.1%), as was the incidence of BPAR (17.7% vs. 23.1%, both n.s.). The overall incidence, severity and pattern of AEs were comparable between EC-MPS and MMF in de novo patients. This was supported by the safety results assessed in maintenance patients (B302) indicating no increased safety risk with the use of EC-MPS in the diabetic patient population, if compared with MMF. Likewise, apart from a higher incidence of severe/serious infections in diabetics, the safety profile of EC-MPS was not different to non-diabetics in myPROMS. In conclusion, preliminary data suggest that EC-MPS in combination with cyclosporine (+/- steroids) can be used efficiently and safely for the prophylaxis of organ rejection in diabetic renal transplant patients. Moreover, diabetic patients can apparently be safely converted from MMF to EC-MPS. More data from prospective studies are needed to fully judge the efficacy and safety profile of EC-MPS in the diabetic transplant population.

Randomized double-blind study of immunoprophylaxis with basiliximab, a chimeric anti-interleukin-2 receptor monoclonal antibody, in combination with mycophenolate mofetil-containing triple therapy in renal transplantation.

BACKGROUND: Acute rejection remains a major problem in renal transplantation. Immunoprophylaxis with basiliximab (Simulect) has achieved significant reductions in acute rejection episodes in renal allograft recipients receiving dual immunosuppression. This study explored the tolerability and cumulative benefit of combining basiliximab with triple-drug therapy-cyclosporine (USP Modified, Neoral), mycophenolate mofetil, and steroids. METHODS: In a randomized, double-blind, placebo-controlled, multicenter study, 123 kidney transplant recipients received either basiliximab at 20 mg before transplantation (day 0) and 20 mg on day 4 (n=59), or placebo (n=64). All received triple-drug immunosuppression and were followed for 6 months. RESULTS: Tolerability of basiliximab was equivalent to placebo, with no increase in serious adverse events, infection, malignancy, or posttransplant lymphoproliferative disorder. At 6 months, there were trends in favor of basiliximab over placebo in the incidences of first biopsy-confirmed acute rejection (15.3% vs. 26.6%, P=NS) and of acute rejection treated with antibody (5.1% vs. 15.6%, P=NS). Kaplan-Meier estimates at 4 weeks and 6 months were significantly in favor of basiliximab treatment for first acute rejection, biopsy-confirmed rejection, rejection episodes treated with antibody therapy, and treatment failure. Renal function improved more rapidly in the basiliximab group, with mean creatinine clearance at week 2 being 54.7 mL/min versus 43.2 mL/min for placebo (P=0.034). At 12 months, patient survival was 100% in both groups; graft survival was 94.9% with basiliximab and 92.2% with placebo. CONCLUSIONS: Basiliximab immunoprophylaxis is safe, well tolerated, and shows a trend toward reduction in number of acute rejection episodes in renal transplant patients receiving cyclosporine, mycophenolate mofetil, and steroids.