Robert Mendez

Results of the double-blind, randomized, multicenter, phase III clinical trial of thymoglobulin versus Atgam in the treatment of acute graft rejection episodes after renal transplantation

BACKGROUND Thymoglobulin, a rabbit anti-human thymocyte globulin, was compared with Atgam, a horse anti-human thymocyte globulin for the treatment of acute rejection after renal transplantation. METHODS A multicenter, double-blind, randomized trial with enrollment stratification based on standardized histology (Banff grading) was conducted. Subjects received 7-14 days of Thymoglobulin (1.5 mg/kg/ day) or Atgam (15 mg/kg/day). The primary end point was rejection reversal (return of serum creatinine level to or below the day 0 baseline value). RESULTS A total of 163 patients were enrolled at 25 transplant centers in the United States. No differences in demographics or transplant characteristics were noted. Intent-to-treat analysis demonstrated that Thymoglobulin had a higher rejection reversal rate than Atgam (88% versus 76%, P=0.027, primary end point). Day 30 graft survival rates (Thymoglobulin 94% and Atgam 90%, P=0.17), day 30 serum creatinine levels as a percentage of baseline (Thymoglobulin 72% and Atgam 80%; P=0.43), and improvement in posttreatment biopsy results (Thymoglobulin 65% and Atgam 50%; P=0.15) were not statistically different. T-cell depletion was maintained more effectively with Thymoglobulin than Atgam both at the end of therapy (P=0.001) and at day 30 (P=0.016). Recurrent rejection, at 90 days after therapy, occurred less frequently with Thymoglobulin (17%) versus Atgam (36%) (P=0.011). A similar incidence of adverse events, post-therapy infections, and 1-year patient and graft survival rates were observed with both treatments. CONCLUSIONS Thymoglobulin was found to be superior to Atgam in reversing acute rejection and preventing recurrent rejection after therapy in renal transplant recipients.

Everolimus versus Mycophenolate Mofetil in the Prevention of Rejection in De Novo Renal Transplant Recipients: A 3-year Randomized, Multicenter, Phase Iii Study

Background. This 36-month, randomized, parallel-group study compared safety and efficacy of two doses of everolimus with mycophenolate mofetil (MMF) in de novo renal-transplant recipients. Methods. Renal-allograft recipients received 1.5 mg/day or 3 mg/day of everolimus or 2 g/day of MMF, plus full-dose cyclosporine (CsA) and corticosteroids after randomization. For at least their first year, patients received study medication according to a double-blinded, double-dummy design. Concerns over nephrotoxicity led to a protocol amendment to an open-label design with reduced CsA troughs. Results. Incidences of primary efficacy failure at 36 months (biopsy-proven acute rejection, graft loss, death, or loss to follow-up) were everolimus 1.5 mg/day, 33.7% (65/193); everolimus 3 mg/day, 34.0% (66/194); and MMF, 31.1% (61/196) (P=0.810). Antibody-treated acute rejection at 36 months was significantly lower with everolimus 1.5 mg (9.8%) than MMF (18.4%, P=0.014). Discontinuation for adverse events was more frequent with everolimus and hemolytic uremic syndrome, lymphoproliferative disease, and proteinuria, and higher serum creatinine occurred at increased frequency relative to the MMF arm. Creatinine levels in the everolimus arms were stable in follow-up: the mean rise in creatinine over the first 6 months of the open-label phase was 3 &mgr;mol/L or greater with everolimus and 7 &mgr;mol/L with MMF. However, serum creatinine levels were lower in the MMF group throughout. Death and graft loss were higher in the everolimus arms (not significant). Conclusions. As part of triple-drug immunosuppression, everolimus (1.5 or 3 mg/day) was as efficacious as MMF, although the side-effect profile featured increased adverse events. Nephrotoxicity/calcineurin–inhibitor-related adverse events will require judicious lowering of CsA exposure with monitoring of everolimus troughs.

Randomized trial of tacrolimus in combination with sirolimus or mycophenolate mofetil in kidney transplantation: results at 6 months.

Background. This is the first report of a randomized, multicenter, clinical trial comparing the combination of sirolimus or mycophenolate mofetil (MMF) with tacrolimus-based immunosuppression in kidney transplantation. Results at 6 months of follow-up are presented. Methods. Before transplantation, patients were randomized to receive tacrolimus plus corticosteroids with sirolimus (n=185) or MMF (n=176). The primary endpoint of the study was the incidence of biopsy-confirmed acute rejection. Patient and graft survival, renal function, and composite endpoints also were evaluated. Safety was assessed by monitoring laboratory parameters and adverse events. Results. By 6 months of follow-up, the incidence of biopsy-confirmed acute rejection was similar in both treatment groups (13.0% tacrolimus+sirolimus vs. 11.4% tacrolimus+MMF;P =0.64 log-rank). Patient survival (97.3% tacrolimus+sirolimus vs. 97.7% tacrolimus+MMF) and graft survival (93.0% tacrolimus+sirolimus vs. 95.5% tacrolimus+MMF) were equivalent (P =0.53, overall survival log-rank). There was a significantly higher incidence of study drug discontinuation in patients receiving sirolimus (21.1% vs. 10.8%;P =0.008). Renal function was significantly better in the MMF-treatment group (serum creatinine 1.44±0.45 mg/dL vs. 1.77±1.42 mg/dL;P =0.018). Hyperlipidemia was significantly more prevalent in the sirolimus-treatment group. Diastolic blood pressure was significantly higher in sirolimus-treated patients. There were significantly more leukopenia and gastrointestinal adverse events in the MMF-treatment group. The incidence of posttransplant diabetes mellitus was 7.6% in the sirolimus group and 7.7% in the MMF group. Conclusion. Tacrolimus is equally effective in renal transplantation when combined with sirolimus or MMF. The tacrolimus-MMF combination may be superior in terms of improved renal function and improved cardiovascular risk factors including hyperlipidemia and hypertension.

An open-label, concentration-ranging trial of FK506 in primary kidney transplantation : A report of the United States Multicenter FK506 Kidney Transplant group

This was a multicenter, open-label, concentration-ranging trial of FK506 and cyclosporine in 120 patients undergoing primary cadaveric kidney transplant. Patients were randomized to a cyclosporine-based regimen or to one of three FK506-based regimens designed to achieve low (5-14 ng/ml), medium (15-25 ng/ml), or high (26-40 ng/ml) trough whole blood levels. Corresponding initial doses of FK506 were 0.2, 0.3, and 0.4 mg/kg/day. Patients were evaluated at 42 days after transplant for the occurrence of the first episode of acute rejection or toxicity, necessitating a dosage reduction. There was no significant difference among the three FK506-based regimens and the cyclosporine-based regimen for rejection or toxicity at 42 days. However, the incidence of acute rejection was significantly lower (14% for FK506 and 32% for cyclosporine; P=0.048) for the aggregate of all FK506-treated patients versus cyclosporine. The incidence of neurotoxic and gastrointestinal events was higher among FK506-treated patients during the first month after transplant. A significant trend was observed for increasing toxicity with increasing maximum trough FK506 concentrations (P=0.01) and for decreasing rates of rejection with increasing minimum trough FK506 concentrations (P=0.021). FK506 was effective in preventing early rejection in kidney transplant recipients. The target range of whole blood levels that optimizes efficacy and minimizes toxicity seems to be 5-15 ng/ml. The corresponding recommended initial dose of FK506 for kidney transplant recipients seems to be 0.2 mg/kg/day.

A Phase I/II Randomized Open‐Label Multicenter Trial of Efalizumab, a Humanized Anti‐CD11a, Anti‐LFA‐1 in Renal Transplantation

Leukocyte function associated antigen‐1 (LFA‐1) has a multifaceted role in the immune response, including adhesion and trafficking of leukocytes, stabilizing the immune synapse of the MHC‐TCR complex and providing costimulation signals. Monoclonal antibodies to the CD11a chain of LFA‐1 have been seen to result in effective immunosuppression in experimental models. Efalizumab, a humanized IgG1 anti‐CD11a, is approved for use in psoriasis and may provide effective immunosuppression in organ transplantation. Thirty‐eight patients undergoing their first living donor or deceased renal transplant were randomized to receive efalizumab 0.5 or 2 mg/kg weekly subcutaneously for 12 weeks. Patients were maintained on full dose cyclosporine, mycophenolate mofetil and steroids or half dose cyclosporine, sirolimus and prednisone. At 6 months following transplant patient survival was 97% and graft survival was 95%. Clinical biopsy‐proven acute rejection in the first 6 months after transplantation was confirmed in 4 of 38 patients (11%). Three patients (8%) developed post transplant lymphoproliferative disease, all treated with the higher dose efalizumab and full dose cyclosporine. The two doses of efalizumab resulted in comparable saturation and modulation of CD11a. This phase II trial suggests that efalizumab may warrant further investigation in transplantation.

Safety And Efficacy Of Tacrolimus In Combination With Mycophenolate Mofetil (mmf) In Cadaveric Renal Transplant Recipients1

BACKGROUND Tacrolimus (FK506) is a safe and effective treatment for the prevention of rejection of renal allografts. Mycophenolate mofetil (MMF) has been used as adjunct immunosuppressive therapy with cyclosporine and corticosteroids for the same purpose. The objective of this study was to investigate the safety and efficacy of FK506 and MMF in renal transplant recipients. METHODS After cadaveric renal transplant, patients were randomized to receive tacrolimus in combination with either azathioprine (AZA, n=59), MMF 1 g/day (n=59), or MMF 2 g/day group (n=58). Patients were followed for 1 yr posttransplant for the incidence of biopsy-confirmed acute rejection, patient and graft survival, and adverse events. RESULTS Tacrolimus doses and trough concentrations were similar between treatment groups at all time points; 80% of patients were maintained within a range of 5.0-13.9 ng/ml at 12 months posttransplant. The mean dose of MMF decreased in the 2 g/day group to 1.5 g/day by 6 months posttransplant, primarily due to gastrointestinal GI-related disorders. The incidence of biopsy-confirmed acute rejection at 1 year was 32.2%, 32.2%, and 8.6% in the AZA, MMF 1 g/day, and MMF 2 g/day groups, respectively (P<0.01). The use of antilymphocyte antibodies for the treatment of rejection was comparable across treatment groups. The incidence of most adverse events was similar across treatment groups and comparable with previous reports. The overall incidence of posttransplant diabetes mellitus was 11.9%, with the lowest rate observed in the MMF 2 g/day group (4.7%), and was reversible in 40% of patients. The incidence of malignancies and opportunistic infections was low and not different across treatment groups. CONCLUSION Tacrolimus in combination with an initial dose of MMF 2 g/day is a very effective and safe regimen in cadaveric kidney transplant recipients.

A multicenter trial of FK506 (tacrolimus) therapy in refractory acute renal allograft rejection

A multicenter trial was conducted to evaluate the efficacy and safety of tacrolimus in the treatment of refractory renal allograft rejection. Renal transplant recipients experiencing biopsy-proven recurrent acute allograft rejection were eligible if the current rejection episode was refractory to corticosteroids. A total of 73 patients were enrolled, of whom 59 (81%) had previously received at least one course of antilymphocyte antibody as rejection therapy. One-year follow-up was available in 93% of patients. Median time to tacrolimus rescue therapy was 75 days after transplantation (range, 18-1448 days). Therapeutic responses to tacrolimus included improvement in 78% of patients, stabilization in 11%, and progressive deterioration in 11%. The risk of experiencing progressive deterioration was related to the pretacrolimus serum creatinine level: serum creatinine < or = mg/dl, 3%; 3.1-5 mg/dl, 16% (P < 0.04); > 5 mg/dl, 23% (P < 0.02). Twelve-month (from the time of initiation of tacrolimus therapy) actuarial patient and graft survival rates were 93% and 75%. Graft loss occurred in 19 patients (25%) at a median time of 108 days. Fourteen episodes of recurrent rejection were diagnosed in 10 patients (14%), at a median time of 101 days. Eleven episodes of recurrent rejection were treated (three patients underwent transplant nephrectomy), with resolution achieved in nine patients. Antilymphocyte antibody therapy was not used to treat recurrent rejection. Serum creatinine values improved during tacrolimus therapy: median serum creatinine level before tacrolimus, 3.2 mg/dl; median at 1 year after tacrolimus, 1.8 mg/dl. Twelve infections were documented in 11 patients (15%), including cytomegalovirus infection in three patients (4%). Posttransplant lymphoproliferative disorder was diagnosed in a single patient. Tacrolimus whole blood levels averaged 15.0 +/- 9.9 ng/ml at day 7 of tacrolimus therapy and 9.4 +/- 5.1 ng/ml at 1 year, and were consistent among individual centers. Treatment outcome did not correlate with tacrolimus blood levels. The most commonly observed adverse events were neurological and gastrointestinal. Seventy-four percent of patients received tacrolimus for at least 1 year. Tacrolimus therapy was discontinued in 18% of patients for rejection (11% for progressive, unrelenting rejection, and 7% for recurrent rejection). Tacrolimus therapy was discontinued in 8% of patients due to adverse events. In conclusion, tacrolimus rescue therapy provides (1) prompt, effective reversal of refractory renal allograft rejection, (2) good long-term renal allograft function, (3) a low incidence of recurrent rejection, and (4) an acceptable safety profile in renal allograft recipients experiencing refractory rejection.

A prospective, randomized trial of tacrolimus in combination with sirolimus or mycophenolate mofetil in kidney transplantation: results at 1 year.

Background. This is the 1-year report of a randomized, multicenter, clinical trial comparing the combination of sirolimus or mycophenolate mofetil (MMF) with tacrolimus-based immunosuppression in kidney transplantation. Methods. Prior to transplantation, recipients were randomized to receive tacrolimus plus corticosteroids with either sirolimus (n=185) or MMF (n=176). The incidence of biopsy-confirmed acute rejection at 6 months was the primary endpoint of the study. Patient and graft survival, renal function, study drug dosing and discontinuations were evaluated at 1 year. Results. At 1 year, there was no difference in patient survival (95.7% sirolimus vs. 97.2% MMF; P=0.45) or graft survival (90.8% sirolimus vs. 94.3% MMF; P=0.22). Patients without delayed graft function (DGF) receiving MMF had significantly better graft survival (99% vs. 93%; P=0.01). Patients receiving a transplant from a live donor had a trend towards better graft survival with MMF as compared to sirolimus (98% vs. 91%; P=0.07). Patients receiving sirolimus had a significantly higher incidence of study drug discontinuation (26.5% vs. 14.8% MMF; P=0.006). Patients receiving MMF had significantly better renal function as shown by median serum creatinine levels (1.3 mg/dL vs. 1.5 mg/dL; P=0.03) and a trend towards higher calculated creatinine clearance (CrCl), (58.4 ml/min vs. 54.3 ml/min; P=0.06). More patients in the sirolimus group had a serum creatinine >2.0 mg/dL, (20.4% vs. 11.0%; P=0.02). Conclusions. Tacrolimus is safe and effective in live and deceased donor kidney transplantation when given in combination with sirolimus or MMF. Patient and graft survival were excellent in both arms. Renal function is superior for patients treated with tacrolimus + MMF combination.

Pulsatile perfusion reduces the incidence of delayed graft function in expanded criteria donor kidney transplantation.

The use of expanded criteria donors (ECD) has been proposed to help combat the discrepancy between organ availability and need. ECD kidneys are associated with delayed graft function (DGF) and worse long‐term survival. The aim of this study is to evaluate the impact of pulsatile perfusion (PP) on DGF and graft survival in transplanted ECD kidneys. From January 2000 to December 2003, 4618 ECD kidney‐alone transplants were reported to the United Network for Organ Sharing. PP was performed on 912 renal allografts. The prognostic factors of DGF were analyzed using multivariate logistic regression analysis. Risk factors for reduced allograft viability were greater in donors and recipients of PP kidneys. Three‐year graft survival of ECD kidneys preserved with PP was similar to cold storage (CS) kidneys. The incidence of DGF in PP kidneys was significantly lower than CS kidneys (26% vs. 36%, p < 0.001). Despite having a greater number of risk factors for reduced graft viability, the ECD‐PP kidneys had similar graft survival compared to ECD‐CS kidneys. The use of PP, by decreasing the incidence of DGF, may possibly lead to lower overall costs and increased utilization of donor kidneys.

One-year follow-up of an open-label trial of FK506 for primary kidney transplantation. A report of the U.S. Multicenter FK506 Kidney Transplant Group.

Patients undergoing primary cadaveric kidney transplantation were followed for 1 year as part of a phase II, multicenter, open-label concentration-ranging trial of FK506 and cyclosporine. One hundred twenty patients were randomly assigned to a cyclosporine-based regimen or one of three FK506-based regimens designed to achieve low (5-14 ng/ml), medium (15-25 ng/ml), or high (26-40 ng/ml) trough whole blood levels. Corresponding initial doses of FK506 were 0.2, 0.3, or 0.4 mg(kg/day, respectively. Patients with toxicity to FK506 had their target concentration reduced by lowering the dose of FK506. Ninety-two patients completed a 1-year follow-up to determine patient and graft survival and long-term safety. At 1-year, the patient survival rate was 98% for FK506 and 92% for cyclosporine, and the graft survival rate was 93% and 89% in the FK506 and cyclosporine groups, respectively. The incidence of acute rejection was significantly lower (14% FK506, 32% cyclosporine, P=0.048) at day 42 after transplantation. However, the incidence of rejection episodes requiring treatment at 1 year was similar in both groups (33% for FK506 and 32% for cyclosporine). Nephrotoxicity occurred with a similar frequency with FK506 and cyclosporine, but the incidence of neurotoxic events and the incidence of new insulin use were higher among FK506-treated patients. The target range of whole blood levels that optimizes efficacy and minimizes toxicity seems to be 5-15 ng/ml. The corresponding recommended initial dose of FK506 for kidney transplant recipients is 0.2 mg/kg/day. These results indicate that the efficacy and safety of FK506 were comparable to that for cyclosporine for primary immunosuppression in patients undergoing cadaveric kidney transplantation.