Anne Boucher

A randomized, prospective multicenter pharmacoepidemiologic study of cyclosporine microemulsion in stable renal graft recipients. Report of the Canadian Neoral Renal Transplantation Study Group.

BACKGROUND The safety, tolerability, and pharmacokinetics of conventional cyclosporine (ConCsA) and cyclosporine microemulsion (MeCsA) were compared under conditions of normal clinical practice in a prospective, randomized, concentration-controlled, pharmacoepidemiologic study. METHODS Between September 1994 and March 1995, 1097 stable renal transplant recipients in 14 Canadian centers were randomized 2:1 to treatment with MeCsA or ConCsA. Patients were commenced on each study drug at a dose equal to their previous therapy with ConCsA, and the dose was adjusted to maintain predose whole blood cyclosporine concentrations within the therapeutic range established for each center. Prednisone and azathioprine were continued unless dose adjustment was required for clinical reasons. RESULTS The mean cyclosporine concentration was comparable in both treatment groups at all time points throughout the 6 months of follow-up. The mean dose of cyclosporine was 3.6 mg/kg/day in both treatment groups at entry to the study, and declined by 0.3% and by 2.8% in patients receiving ConCsA and MeCsA, respectively. The nature and severity of adverse events were similar in both treatment groups, but there was a transient increase in neurological and gastrointestinal complications in the group receiving MeCsA within the first month after conversion (P<0.05). Serum creatinine and creatinine clearance did not change in either treatment group throughout the study. Biopsy-proven acute rejection occurred in three patients (0.8%) receiving ConCsA and in seven patients (0.9%) receiving MeCsA, with non-histologically proven acute rejection in an additional three patients (0.8%) receiving ConCsA and five patients (0.6%) receiving MeCsA (P=NS). Serum creatinine rose transiently in 35 patients (9.8%) receiving ConCsA and 138 patients (18.7%) receiving MeCsA (P<0.05) and resolved either spontaneously or after a reduction in the cyclosporine dose. One graft was lost in the MeCsA group due to irreversible rejection, and seven patients died, three in the group receiving ConCsA and four of those receiving MeCsA (P=NS). Absorption of cyclosporine was more rapid and complete from MeCsA than from ConCsA during the first 4 hr of the dosing interval, resulting in almost 40% greater exposure to the drug (P<0.001). There was close correlation between area under the time-concentration curve (AUC) over the first 4 hr of the 12-hr dosage interval and AUC over the entire 12-hr dosage interval for both formulations, making AUC over the first 4 hr a good predictor of total cyclosporine exposure. Using this parameter, patients with low absorption randomized to receive MeCsA showed a marked increase in drug exposure by months 3 and 6, whereas there was no change in those who continued on ConCsA. A limited sampling strategy utilizing samples at the predose and postdose trough levels provided an excellent correlation with drug exposure, particularly for patients receiving MeCsA (r2=0.94 MeCsA vs. r2=0.89 ConCsA). CONCLUSIONS MeCsA appears to be a safe and effective therapy in stable renal transplant patients and provides superior and more consistent absorption of cyclosporine when compared with ConCsA. Transient toxicity after conversion to MeCsA occurs in some patients, and may reflect the increased exposure to cyclosporine. Use of a limited sampling approach combining trough and 2-hr postdose concentrations may provide an effective way to monitor this exposure.

Lack of Benefit of Early Protocol Biopsies in Renal Transplant Patients Receiving TAC and MMF: A Randomized Study

We conducted a randomized, multicenter study to determine whether treatment of subclinical rejection with increased corticosteroids resulted in beneficial outcomes in renal transplant patients receiving tacrolimus (TAC), mycophenolate mofetil (MMF) and prednisone. One hundred and twenty‐one patients were randomized to biopsies at 0,1,2,3 and 6 months (Biopsy arm), and 119 to biopsies at 0 and 6 months only (Control arm). The primary endpoint of the study was the prevalence of the sum of the interstitial and tubular scores (ci + ct)> 2 (Banff) at 6 months. Secondary endpoints included clinical and subclinical rejection and renal function. At 6 months, 34.8% of the Biopsy and 20.5% of the Control arm patients had a ci + ct score ≥ 2 (p = 0.07). Between months 0 and 6, clinical rejection episodes were 12 in 10 Biopsy arm patients and 8 in 8 Control arm patients (p = 0.44). Overall prevalence of subclinical rejection in the Biopsy arm was 4.6%. Creatinine clearance at 6 months was 72.9 ± 21.7 in the Biopsy and 68.90 mL/min ± 18.35 mL/min in the Control arm patients (p = 0.18). In conclusion, we found no benefit to the procurement of early protocol biopsies in renal transplant patients receiving TAC, MMF and prednisone, at least in the short term. This is likely due to their low prevalence of subclinical rejection.

Safety and tolerability of cyclosporine and cyclosporine microemulsion during 18 months of follow-up in stable renal transplant recipients: a report of the Canadian Neoral Renal Study Group.

BACKGROUND There has been concern that the increased drug exposure associated with treatment with cyclosporine microemulsion (CsA-ME) would lead to an increase in adverse events. METHODS The long-term safety and tolerability of conventional cyclosporine (CsA) and CsA-ME were compared in a randomized, multicenter, pharmacoepidemiologic study involving 1097 stable renal transplant patients after 18 months of follow-up. RESULTS No significant difference was seen in change in serum creatinine or calculated creatinine clearance between the two groups. Episodes of deterioration in renal function (change in serum creatinine > or = 20%) were categorized with the following results for CsA-ME versus CsA, respectively: acute rejection, 4.5% vs. 4.5%; chronic rejection, 8% vs. 11%; CsA nephrotoxicity, 12% vs. 7% (P=0.008); transient changes, 17% vs. 12%; other causes, 4% vs. 6%. During the first 6 months of the study, a transient increase in the incidence of gastrointestinal and neurological adverse events was seen in the CsA-ME group compared with the CsA group. Up to 18 months, patients in the CsA group reported significantly fewer hearing and vestibular disorders, but more cardiovascular problems than those in the CsA-ME group (P=0.035). CONCLUSIONS Tolerance to CsA and CsA-ME was similar. Renal function over 18 months was not adversely affected by the increased drug exposure with CsA-ME, although there was a transient increase in nephrotoxicity. The frequency of acute and chronic rejection did not change.

Factors associated with progression of interstitial fibrosis in renal transplant patients receiving tacrolimus and mycophenolate mofetil.

Background. We recently reported a randomized study in renal transplant patients (RTP) receiving tacrolimus, mycophenolate mofetil, and prednisone in which patients who had early protocol biopsies (PBx) derived no benefit compared with controls (no PBx) at 6 months, likely due to the low prevalence of subclinical rejection. We report on the follow-up of these patients to 24 months at which time a repeat PBx and tests of renal function were performed. Methods. Of the 240 RTP randomized, 22 were excluded for a protocol violation. Approximately 75% of the remaining 218 (111 PBx and 107 controls) completed the study. Results. At 24 months, graft function was excellent with a mean creatinine clearance of approximately 74 mL/min and negligible proteinuria; however, the prevalence of interstitial fibrosis and tubular atrophy (IF/TA)—ci + ct more than or equal to 2—increased from approximately 3% at baseline to up to 40% to 50%. By logistic regression analysis, the only independent positive correlate of IF/TA was transplantation with a deceased donor. However, by post hoc analysis, use of angiotensin-II-converting enzyme inhibitors or angiotensin II receptor blockers was negatively correlated with both the prevalence of IF/TA at 24 months and its progression between 6 and 24 months in RTP that had paired biopsies. Conclusions. A regimen of tacrolimus, mycophenolate mofetil, and prednisone results in excellent renal function at 24 months posttransplant but with a progressive increase in IF/TA. A potential inhibitory effect of angiotensin-II-converting enzyme inhibitor/angiotensin II receptor blockers on IF/TA is suggested that requires confirmation in a randomized study.

A Prospective 3-yr Evaluation of Tacrolimus-based Immunosuppressive Therapy in Immunological High Risk Renal Allograft Recipients

Abstract:  Background:  There have been no published data on use of the the newer immunosuppressants tacrolimus and mycophenolate mofetil (MMF) in high immunological risk renal transplantation. We therefore undertook a prospective study to systematically assess outcomes using these agents as part of an aggressive immunosuppressive regimen.

Eculizumab for the Treatment of Severe Antibody-Mediated Rejection: A Case Report and Review of the Literature.

In renal transplantation, treatment options for antibody-mediated rejection are limited. Here, we report a case of severe AMR treated with eculizumab. A 50-year-old woman known for end stage kidney disease secondary to IgA nephropathy received a kidney transplant from a 50-year-old deceased donor. At 5 months after transplantation, she presented with acute graft dysfunction and biopsy showed a severe antibody-mediated rejection associated with thrombotic microangiopathy. Despite an aggressive conventional immunosuppressive regimen, signs of rejection persisted and the patient was treated with 3 doses of eculizumab. Following the therapy, markers of TMA improved and graft function stabilized. However, ongoing signs of rejection remained in the repeated biopsy. In kidney transplantation, eculizumab is an expensive treatment and its role in the treatment of antibody-mediated rejection remains to be determined.

The incidence, management, and evolution of rapamycin-related side effects in kidney transplant recipients

Conversion from a calcineurin‐inhibitor‐based immunosuppression to a rapamycin‐based immunosuppression may preserve kidney graft function. The side effects of rapamycin can limit its usefulness, but their management and evolution are rarely reported in clinical trials. We performed a retrospective cohort study in patients transplanted before December 31, 2008 and who received rapamycin to replace calcineurin inhibitors. In 219 patients studied, 98% presented ≥1 side effects after starting rapamycin. Side effects occurring in ≥10% of patients were dyslipidemia (52%, 95% confidence interval (CI): 45–59%), peripheral edema (37%, 95%CI: 31–43%), cytopenia (36%, 95% CI: 30–42%), acne (29%, 95% CI: 23–35%), proteinuria (23%, 95% CI: 17–29%), and oral ulcers 14% (95% CI: 10–18%). Proteinuria, ulcers, and edema were difficult to manage and were more likely to cause cessation of rapamycin. Rapamycin was discontinued in 46% of patients (95% CI: 40–52%). Age (odds ratio [OR] per 10‐yr increase: 1.29, 95% CI: 1.05–1.59) and obesity (OR: 2.57, 95% CI: 1.10–6.01) were independently associated with cessation of rapamycin. We conclude that successful control of dyslipidemia and cytopenia can be achieved without discontinuing rapamycin. Most other side effects are harder to manage. Leaner and younger patients are less likely to discontinue rapamycin due to side effects.

Five-year study of tacrolimus as secondary intervention versus continuation of cyclosporine in renal transplant patients at risk for chronic renal allograft failure.

Background. Chronic allograft nephropathy is the most frequent cause of long-term kidney allograft loss. Studies are desperately needed to improve long-term survival. Tacrolimus has been associated with less rejection and better kidney function compared with cyclosporine in clinical trials. This study tested the hypothesis that conversion from cyclosporine to tacrolimus might improve long-term outcomes in patients with chronic allograft damage. Methods. In this multicenter Canadian clinical trial, cyclosporine-treated patients with biopsy-proven chronic allograft nephropathy and impaired renal function were randomly assigned (2:1) to convert to tacrolimus or continue on cyclosporine therapy. A total of 106 (70 tacrolimus and 36 cyclosporine treated) patients were followed-up for up to 5 years. The primary outcome was graft survival. Results. In an intention to treat analysis, subsequent graft (73% vs. 81%, P=0.2835, log-rank test) and patient survival (91% vs. 92%, P=0.8668, log-rank test) were not different between the tacrolimus and cyclosporine groups, respectively. Changes in Chronic Allograft Damage Index scores on protocol biopsies from baseline to 3 years were not different (+0.4±1.8 vs. +1.3±3.2, P=0.5910, cyclosporine vs. tacrolimus, respectively). There were no significant differences in biopsy-proven acute rejection (6 [8.6%] vs. 2 [5.6%], tacrolimus vs. cyclosporine, respectively, P=0.5906). Conclusions. In this study, patients with chronic allograft damage converted from cyclosporine to tacrolimus demonstrated no apparent benefit.

Sirolimus Immunoprophylaxis and Renal Histological Changes in Long-Term Cardiac Transplant Recipients A Pilot Study

Background: The effects of sirolimus (SIR), as a substitution for calcineurin inhibitor (CNI) immunoprophylaxis, on renal function in very-long-term cardiac transplant recipients have been a matter of controversy. Objective: To assess the impacts of SIR as a substitution for CNI on renal function up to 24 months in long-term cardiac recipients as well as the renal histological changes in patients with suspected CNI-induced nephrotoxicity. Methods: A total of 23 cardiac transplant recipients aged 57.7 ± 11.2 years, 91 months post–cardiac transplantation were recruited; 15 patients were randomized to CNI-free immune suppression with SIR, and 8 patients were allocated to continue their CNI regimens. Serum creatinine and calculated serum creatinine clearance were measured at prespecified time points up to 24 months. Renal structure and function were assessed by renal biopsies, renal ultrasound, and magnetic resonance imaging at baseline. Results: There were no significant changes in creatinine clearance during the course of the study in patients treated with SIR. However, SIR-treated patients exhibited a significant decrease in 24-hours and nighttime systolic and diastolic blood pressures. Typical findings of significant hypertensive renal disease were detected in 9 of the 11 (82%) patients. Features of chronic CNI toxicity were detected in 6 (55%) patients. Conclusions: There is a very high rate of hypertensive renal disease concomitantly with some degree of CNI toxicity in long-term cardiac transplant recipients with renal dysfunction. This very high rate of hypertension-related disease may limit the impact of SIR on improving renal function long term following cardiac transplantation.

Conversion from calcineurin inhibitors to sirolimus in kidney transplant recipients: a retrospective cohort study.

BACKGROUND Replacing a calcineurin inhibitor (CNI) with sirolimus (SRL) may preserve kidney graft function. However, at the present time, only short follow-up after conversion is available. The aim of this study was to assess whether conversion from a CNI-based to an SRL-based maintenance regimen was safe and effective. MATERIALS AND METHODS We performed a retrospective cohort study among kidney graft patients whose CNI was withdrawn to be replaced by SRL. Two-tailed paired t tests were used to compare glomerular filtration rates (GFRs) and proteinuria levels before and up to 2 years after conversion. We used linear regression to determine the factors associated with changes in renal function after conversion. RESULTS The 193 study subjects had a mean GFR at conversion of 41 +/- 16 mL/min/1.73 m(2) a median proteinuria level of 0 g/L (interquartile range = 0-0.15). After conversion, the GFR was stable: at 1 year, the change was -0.34 mL/min/1.73 m(2) (95% confidence interval [CI] = -2.71, 2.03) and at 2 years, -0.96 mL/min/1.73 m(2) (95% CI = 4.26, 2.34). There was a small but significant increase in dipstick proteinuria at 1 year of +0.5 g/L, (95% CI = 0.20, 0.75). On multivariate analysis, proteinuria > or = 1 g/L at the time of conversion was the only predictor of deteriorating GFR at 1 year (beta: -7.91 mL/min/1.73 m(2); 95% CI = -14.10, -1.70). SRL had to be discontinued in 31% of patients. CONCLUSION Conversion from CNI to SRL resulted in stable graft function at 2 years and in a slight increase in proteinuria. Despite the relatively high reconversion rate, this strategy offers a reasonable alternative to CNIs for most patients.