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Clinical and Translational Research

Randomized Trial of Everolimus-Facilitated Calcineurin Inhibitor Minimization Over 24 Months in Renal Transplantation

Cibrik, Diane1,11; Silva, Helio Tedesco Jr.2; Vathsala, Anantharaman3; Lackova, Eva4; Cornu-Artis, Catherine5; Walker, Rowan G.6; Wang, Zailong7; Zibari, Gazi B.8; Shihab, Fuad9; Kim, Yu S.10

Author Information
doi: 10.1097/TP.0b013e3182848e03

Although calcineurin inhibitors (CNIs) have dramatically reduced acute rejection rates in kidney transplantation, their associated nephrotoxicity contributes to chronic allograft dysfunction (1). CNIs may also exacerbate risk factors for cardiovascular events and death with a functioning graft (2, 3). In addition, despite excellent 1-year graft survival, long-term outcomes have not improved over the last decade (4). Therefore, a need exists to improve long-term outcomes by maintaining allograft function and minimizing cardiovascular disease, infection, and malignancy, which are common causes of mortality in renal transplantation (5).

Various immunosuppressive strategies involving CNI minimization, elimination, or avoidance have been investigated with the goal of improving long-term graft and patient outcomes while maintaining low rates of acute rejection (6–10). Where the aim has been to reduce long-term cyclosporine A (CsA) exposure, the A2309 study is the largest prospective renal transplantation trial of a mammalian target of rapamycin (mTOR) inhibitor plus reduced-exposure CsA (RD-CsA) to date and was conducted over 2 years. Everolimus targeting trough concentrations between 3–8 and 6–12 ng/mL plus RD-CsA achieved noninferior efficacy and comparable renal function to the control regimen of mycophenolic acid (MPA) plus standard-exposure CsA (SD-CsA) at 12 months. These results were achieved with more than 60% reduction in mean CsA trough concentration in the everolimus groups compared with the control at month 12 (9).

To further establish this regimen as a strategy for improving patient and allograft outcomes, it is critical to determine whether the comparable efficacy and renal function achieved at 12 months with everolimus are sustained. This report summarizes the 24-month outcomes of the A2309 trial, which are of considerable importance, because they provide longer follow-up data from this registration trial of concentration-controlled everolimus plus RD-CsA.

RESULTS

Patient Disposition

Of the 833 patients randomized, 83.8% in the everolimus 3–8 ng/mL, 85.3% in the everolimus 6–12 ng/mL, and 88.8% in the MPA groups completed 2 years of follow-up; the proportions of patients who remained on study medication at 24 months were 60.3%, 57.7%, and 66.8%, respectively. During the second year, fewer patients in the everolimus 3–8 ng/mL group (4.3%, 5%, and 5.4%) discontinued study drug (Fig. 1). Adverse events (AEs) were the most common reason for study drug discontinuation (Fig. 1). Donor and recipient characteristics were generally comparable between groups (Table 1).

TABLE 1
TABLE 1:
Baseline demographics and clinical characteristics of renal transplant recipients and donors (ITT population)
FIGURE 1
FIGURE 1:
Patient disposition over 24 months of treatment. ITT population: all patients randomized after transplantation; safety population: all patients who received at least one dose of study drug and had at least one postbaseline safety assessment.aPrimary reason for discontinuation listed. bEight patients were randomized but did not receive any study medication because of administrative problems (n=4), withdrawal of consent (n=1), AE (n=1), no longer requiring study medication (n=1), and graft loss (n=1). AEs, adverse events; ITT, intent to treat.

Medication Exposure

At month 24, the mean±SD CsA trough level was 42.7±44.44, 47.9±76.93, and 120.5±76.96 ng/mL in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively. For the everolimus groups, 57.3% of patients in the 3–8 ng/mL group and 47.3% in the 6–12 ng/mL group had CsA trough concentrations within the target range of 25–50 ng/mL and 50.6% in the MPA group had CsA trough concentrations within the target range of 100–250 ng/mL. A higher percentage of patients in the everolimus groups than in the MPA group had CsA trough concentrations above the target range at month 24 (everolimus 3–8 ng/mL: 21.5% and 6–12 ng/mL: 28.0% vs. MPA: 4.2%). More patients in the everolimus 3–8 ng/mL group had everolimus trough concentrations above the target range at month 24 (everolimus 3–8 ng/mL: 14.7% vs. 6–12 ng/mL: 8.3%).

Corticosteroids were used in more than 99% of patients in each group during the study with more than 70% receiving corticosteroids without discontinuation throughout the 24-month study period (73.6%, 75.5%, and 70.9% for everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively). The mean±SD daily body-weight-adjusted doses of prednisone-equivalent corticosteroids over the course of the study were 0.4±0.90, 0.4±0.87, and 0.4±0.91 mg/kg per day for the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively.

Efficacy

Efficacy Endpoints

No statistically significant differences were observed in the incidence of composite efficacy failure at month 24 (Table 2; Fig. 2). The incidence of the individual components of the composite endpoint at 24 months is also shown in Table 2.

TABLE 2
TABLE 2:
Summary of efficacy-related results at month 24 (ITT population)
FIGURE 2
FIGURE 2:
Kaplan–Meier estimate of the proportion of patients free from composite efficacy failure defined as treated BPAR, death, graft loss, or loss to follow-up.aLog-rank test. BPAR, biopsy-proven acute rejection; D, day; M, month.

Kaplan–Meier estimates of the proportion of patients free from treated biopsy-proven acute rejection (BPAR), death, graft loss, or loss to follow-up were not significantly different between the treatment groups (P>0.20; Fig. 2). At 24 months, the combined incidence of death, graft loss, or loss to follow-up was significantly higher in the everolimus 3–8 ng/mL group compared with the MPA group (17.3% vs. 11.2% [95% confidence interval (CI) for difference vs. MPA: 0.3, 11.9]; Table 2). A higher number of patients were lost to follow-up in the everolimus 3–8 ng/mL group (7.6%) compared with those receiving everolimus 6–12 ng/mL (5.0%) and MPA (4.3%; Table 2).

The incidences of treated BPAR during the second year were 2.6%, 1.5%, and 1.0%, respectively. Similar to the 12-month data, the majority of BPARs at 24 months were either Banff grade IA or IB, and a higher incidence of Banff grade IIA was observed in the MPA group, although this result was not significant. Two patients in both the everolimus 3–8 ng/mL and the MPA groups experienced Banff grade III BPAR (Table 2). The rates of antibody-treated BPAR were 4.7%, 4.3%, and 5.4% in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively. Few patients experienced recurrent BPAR: 9 (3.2%) patients in the everolimus 3–8 ng/mL group, 8 (2.9%) patients in the 6–12 ng/mL group, and 10 (3.6%) patients in the MPA group had two treated BPARs; 2 (0.7%) patients in the MPA group had three treated BPARs; and 1 (0.4%) patient in the everolimus 3–8 ng/mL group had more than four treated BPARs. C4d staining was performed to detect antibody-mediated rejection in 30.7%, 30.8%, and 27.1% of the patients and was positive in 4.7%, 0.7%, and 3.6% of patients in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively.

Renal Function

Mean estimated glomerular filtration rates (eGFRs; 95% CI for differences vs. MPA) at month 24 were 52.2 (−2.1, 5.5 mL/min/1.73 m2), 49.4 (−4.8, 2.7 mL/min/1.73 m2), and 50.5 mL/min/1.73 m2 for the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively. Modification of Diet in Renal Disease (MDRD) calculation with missing values was imputed as per the statistical plan. Other measures of renal function (eGFR by MDRD without imputation for missing values, eGFR by Nankivell formula, and creatinine clearance by Cockcroft–Gault) are presented in Table 3. When MDRD eGFR was analyzed by National Kidney Foundation (NKF) categories, greater proportions of patients in the everolimus groups had eGFR values ≥60 mL/min/1.73 m2 at month 24 versus the MPA group (everolimus 3–8 ng/mL: 37% and 6–12 ng/mL: 36.4% and MPA: 30.4%), although this difference was not significant (P>0.14; Table 3; see Figure S1, SDC,http://links.lww.com/TP/A781).

TABLE 3
TABLE 3:
Renal function over 24 months of treatment (ITT population)

The incidence of proteinuria AEs at 24 months was higher in patients receiving everolimus (everolimus 3–8 ng/mL: 11.3% [P=0.20 vs. MPA] and 6–12 ng/mL: 13.7% [P=0.04 vs. MPA] and MPA: 8.1%), which was consistent with the trend previously reported at 12 months (9.9%, 13.3%, and 7.7%) (9). For all three groups, the majority of proteinuria was considered to be mild in severity. At 24 months, mean±SD urinary protein-to-creatinine ratios were 388±650.1, 419±728.0, and 179±240.3 mg/g in patients receiving everolimus 3–8 and 6–12 ng/mL and MPA, respectively. The incidence of subnephrotic proteinuria (from 300 to <3000 mg/g urinary protein-to-creatinine ratio) was significantly higher in both everolimus groups compared with the MPA group (everolimus 3–8 ng/mL: 23.8% [P<0.05 vs. MPA] and 6–12 ng/mL: 25.8% [P<0.05 vs. MPA] and MPA: 10.3%). The incidence of nephrotic proteinuria (≥3000 mg/g urinary protein-to-creatinine ratio) was significantly higher in the everolimus 6–12 ng/mL group versus the MPA group (everolimus 3–8 ng/mL: 1.8% and 6–12 ng/mL: 2.5% [P<0.05 vs. MPA] and MPA: 0%).

Safety

Adverse Events

The overall incidence of AEs was comparable among the three groups (everolimus 3–8 ng/mL: 99.3%, everolimus 6–12 ng/mL: 99.3%, and MPA: 98.9%) and they were mainly mild or moderate in severity. The incidence of serious AEs was also comparable between groups at month 24 (everolimus 3–8 ng/mL: 64.2% and 6–12 ng/mL: 69.4% and MPA: 61.5%). A significantly higher overall incidence of AEs leading to discontinuation at 24 months was observed in the everolimus groups versus the MPA group (everolimus 3–8 ng/mL: 28.5% [P=0.03 vs. MPA] and 6–12 ng/mL: 30.6% [P=0.007 vs. MPA] and MPA: 20.5%). AEs of special interest that are associated with mTOR inhibitors are shown in Table 4.

TABLE 4
TABLE 4:
AEs/infections of special interest over 24 months of treatment (safety population)

No statistically significant differences in AEs of interest were observed between the everolimus groups and the MPA group, except for leukopenia, acne, impaired healing, stomatitis and oral ulcers, and new-onset diabetes mellitus (NODM; Table 4). Leukopenia was reported more often in the MPA group (2.9% [P<0.001 vs. MPA] and 2.5% [P<0.001 vs. MPA]; MPA: 12.1%), whereas acne (15.1% vs. 9.2%; P=0.03), impaired healing (4.3% vs. 1.5%; P=0.05), stomatitis/oral ulcers (8.3% vs. 3.3%; P=0.01), and NODM (14.4% vs. 7.3%; P=0.008) were more commonly seen in the everolimus 6–12 ng/mL group compared with the MPA group (Table 4). Wound events between 12 and 24 months were rare across all groups. Interstitial lung disease at 24 months was also rare (everolimus 3–8 ng/mL: 0.7% and 6–12 ng/mL: 1.8% and MPA: 0.4%).

The overall incidence of infections and infestations was lower in the everolimus groups compared with the MPA group at month 24 (everolimus 3–8 ng/mL: 67.9% [P=0.04 vs. MPA] and 6–12 ng/mL: 69.4% [P=0.09 vs. MPA] and MPA: 75.8%). Urinary tract infection was significantly lower in patients receiving everolimus 3–8 ng/mL group compared with those in the MPA group (24.1% vs. 27.1%; P=0.02). At month 24, a lower incidence of cytomegalovirus (CMV) infection (1.5% [P=0.004 vs. MPA] and 0.4% [P<0.001 vs. MPA]; MPA: 6.2%), CMV syndrome (1.5% [P=0.02 vs. MPA] and 1.8% [P=0.04 vs. MPA]; MPA: 5.1%), and CMV disease (0.7% [P=0.06 vs. MPA] and 1.1% [P=0.14 vs. MPA]; MPA: 2.9%) was reported in the everolimus groups compared with the MPA group. Although not captured prospectively, the reported incidence of BK virus infection was higher in MPA-treated patients (0.7% [P=0.004 vs. MPA] and 1.4% [P=0.03 vs. MPA]; MPA: 4.8%; Table 4).

Vital Signs and Laboratory Measurements

Vital signs and laboratory parameters of particular interest obtained at 24 months are shown in Table 5. No significant differences were observed in mean systolic or diastolic blood pressure or in the proportion of patients receiving antihypertensive drugs (everolimus 3–8 ng/mL: 41.2% and 6–12 ng/mL: 38.5% and MPA: 41.8%). No differences in mean hemoglobin, white blood cell count, or platelets were observed. Mean±SD fasting total cholesterol (everolimus 3–8 ng/mL: 217.8±57.37 mg/dL [P<0.001 vs. MPA] and 6–12 ng/mL: 215.1±48.65 mg/dL [P<0.001 vs. MPA]; MPA: 188.0±44.44 mg/dL) and triglyceride concentrations (everolimus 3–8 ng/mL: 214.2±143.54 mg/dL [P=0.002 vs. MPA] and 6–12 ng/mL: 230.1±152.65 mg/dL [P<0.001 vs. MPA]; MPA: 176.1±117.61 mg/dL) were significantly higher for both everolimus groups versus the MPA group (Table 5) and the proportion of patients who received lipid-modifying agents (67.2% [P=0.10 for everolimus 3–8 ng/mL vs. MPA], 76.3% [P<0.001 for everolimus 6–12 ng/mL vs. MPA], and 60.4%) was also higher in the everolimus groups compared with the MPA group.

TABLE 5
TABLE 5:
Summary of vital signs and laboratory parameters at month 24 (safety population)

Major Adverse Cardiac Events

At month 24, major adverse cardiac events (MACE) were comparable between the everolimus 3–8 ng/mL and the MPA groups (2.9% vs. 4.0% [P=0.48] but occurred with a higher incidence in the everolimus 8–12 ng/mL group (7.6% [P=0.08 vs. MPA]). This difference was mainly driven by a greater number of events occurring during the first month and particularly the first 2 weeks after transplantation in patients with preexisting risk factors for such events. In a multivariate logistic regression analysis, baseline age, history of cardiac disease, and history of abuse including alcohol, drug, and tobacco abuse were significantly correlated with increased risk for a MACE event. Treatment group was not significant in the multivariate analysis (P=0.14).

Deaths and Graft Losses

Four patients died in the second year: one due to cardiac arrest on day 602 (everolimus 3–8 ng/mL), one due to presumed acute myocardial infarction on day 528 (everolimus 6–12 ng/mL), and two patients in the MPA group: one due to Pneumocystis jiroveci pneumonia on day 599 and one with West Nile virus infection on day 535. In the second year, nine patients lost their graft (three, four, and two patients in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively). Causes of graft loss in the second year were chronic rejection/chronic allograft nephropathy (two, three, and one patients in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively), noncompliance (one patient in the 6–12 ng/mL group), and infection/septic shock (one patient in the MPA group), and in one patient, in the everolimus 3–8 ng/mL group, the cause was unknown. Eight of the nine patients with graft loss in the second year had discontinued study drug at least 90 days before the reported day of graft loss; the patient who lost his graft while on study drug was in the MPA group.

Death With a Functioning Graft

Of the 27 patients who died during the 24-month study period, deaths with a functioning graft occurred in 7 of 9 patients in the everolimus 3–8 ng/mL group, 9 of 10 patients in the everolimus 6–12 ng/mL group, and 7 of 8 patients in the MPA group.

DISCUSSION

The 2-year follow-up of the A2309 study demonstrated that everolimus allows for substantial and sustained minimization in CsA exposure while maintaining renal function comparable with MPA plus SD-CsA. Comparable composite efficacy failure between the groups was also sustained at 24 months. A significantly higher overall incidence of AEs leading to discontinuation occurred in the everolimus groups.

Although no statistically significant differences were observed in the incidence of composite efficacy failure at month 24, a significantly higher combined incidence of death, graft loss, or loss to follow-up was observed in the everolimus 3–8 ng/mL group most likely due to a higher number of patients lost to follow-up because the combined incidence of death and graft loss was not significantly different. In the everolimus groups, most BPARs occurred within the first 12 months with low incidences in the second year, which were no different to that in the MPA group. In addition, these BPARs were predominantly mild, which is important because the severity of rejection can impact long-term outcomes (11, 12).

Renal function at 12 months after transplantation has been associated with long-term graft function and survival (13–15). In addition, a strong association has been demonstrated between renal function and cardiovascular death in renal transplant recipients independent of the known risk factors for cardiovascular disease (16). In this study, mean eGFR (MDRD) was sustained in the everolimus groups over the 24 months of treatment. When eGFR (MDRD) was analyzed by NKF categories, more patients in the everolimus groups had an eGFR of ≥60 mL/min/1.73 m2 at month 24. These observations may be due to the RD-CsA exposure in the everolimus groups. As for severe proteinuria, the lower incidence in the everolimus 3–8 ng/mL group versus the 6–12 ng/mL group suggests that it may be dependent on everolimus exposure. However, the incidence of reported proteinuria AEs was comparable among the three groups.

Everolimus was generally well tolerated throughout the 24-month study period with a safety profile comparable with that observed for the ∼50,000 patient-years of exposure recorded to date (17). The overall incidence of AEs was similar in the everolimus and MPA treatment groups. Although the overall incidence of AEs leading to drug discontinuation was significantly higher in the everolimus versus the MPA groups over the 24 months, most of these occurred in the first 12 months. Similar to the 12-month study results (9), the 24-month results show that everolimus combined with RD-CsA exposure was associated with a higher incidence of NODM and stomatitis and oral ulcers. MPA combined with SD-CsA was associated with a higher incidence of leukopenia and infections, particularly CMV and BK viral infections.

Although the strength of this study lies in the length of follow-up and in the efficacy in patients on everolimus with reduced exposure to CsA, several challenges should be considered, which are associated with the use of RD-CsA exposure in combination with mTOR inhibitors. Maintaining low CsA trough concentrations remains a challenge as demonstrated by the fact that only 57.3% of patients in the everolimus 3–8 ng/mL group had CsA trough concentrations within target, in part, due to substantial intrapatient variability in CsA trough concentrations within the narrow target range of 25–50 ng/mL. This result may also reflect the reluctance of investigators to target low CsA trough levels in combination with everolimus. Interestingly, the CsA targets for the MPA group, a regimen that is very familiar to most transplant physicians, were achieved in only 50.6% of patients, although the CsA targets were much higher and the CsA range was much wider. Because a higher proportion of everolimus patients had CsA trough levels above target, renal function may have been even better in the everolimus groups if more of the CsA trough levels had been on target. Conversely, efficacy in the everolimus groups may have suffered if more patients had CsA and everolimus levels that were on target (for everolimus 3–8 and 6–12 ng/mL, respectively, 21.5% and 28.0% of CsA and 14.7% and 8.3% of everolimus levels were above target). Nonetheless, renal function was stable and comparable among the three groups at 24 months. A second challenge is the tendency for investigators to discontinue everolimus because they are unfamiliar with it or have a lower threshold for discontinuation due to a previous adverse experience with sirolimus: drug discontinuation rates due to AEs were higher in the everolimus groups versus the MPA group, although the incidence was comparable between the everolimus and MPA groups and was lowest in the everolimus 3–8 ng/mL group.

Of the two everolimus trough-level targets in this trial, 3–8 ng/mL offers similar efficacy and better renal function compared with the 6–12 ng/mL target as well as a benefit on several AEs. For example, the incidence of infection, especially urinary tract infections and viral infections, was lower in the everolimus 3–8 ng/mL group and this observation is noteworthy because infection remains a significant cause of morbidity and mortality after transplantation (13). In contrast, the 6–12 ng/mL everolimus group had a higher incidence of proteinuria, NODM, and stomatitis. Given the challenges associated with achieving and maintaining low CsA exposure after transplantation, these findings support the 12-month data (9) and provide additional confidence in the long-term viability of everolimus-facilitated CNI minimization.

These findings should be interpreted within the context of the study design and extrapolation to other populations should be undertaken cautiously. First, the study population was at low-to-moderate immunologic risk for rejection. Second, the open-label study design may introduce investigator bias during AE reporting and study-drug discontinuation. Although the incidence of viral infections was lower in the everolimus groups, CMV prophylaxis was per center protocol and neither CMV nor BK viremia was prospectively captured. Similarly, NODM assessment was based on center reporting and was not captured uniformly. Currently, the incidence of NODM, BK virus (viremia, viruria, or nephropathy), and CMV (viremia, syndrome, and disease) is being prospectively assessed in the US92 everolimus trial (everolimus+low-dose tacrolimus vs. MPA+standard-dose tacrolimus; ClinicalTrials.gov Identifier: NCT01025817). Last, antibody-mediated rejection on biopsy was not routinely assessed at all centers.

In conclusion, targeting everolimus trough concentrations between 3 and 8 ng/mL plus RD-CsA was associated with the best balance between benefit and risk, achieving comparable efficacy, renal function, and safety but with a higher incidence of AEs leading to everolimus discontinuation compared with the standard immunosuppression regimen. Further improvements in the management of early AEs and long-term follow-up are necessary to fully evaluate the benefits of this CNI-minimizing strategy.

MATERIALS AND METHODS

Study Design

Adult renal transplant recipients who were low-to-moderate immunologic risk were enrolled according to criteria described below and randomized after the transplant surgery to receive reduced-dose CsA in combination with everolimus 0.75 mg BID (targeting blood concentrations of 3–8 ng/mL) or with everolimus 1.5 mg BID (targeting blood concentrations of 6–12 ng/mL) or standard-dose CsA in combination with MPA (1.44 g/day). CsA target ranges from months 6 to 24 were 25–50 ng/mL for the everolimus groups and 100–250 ng/mL for the MPA group. All patients received 20 mg basiliximab 2 hr before transplantation and again on day 4 after transplantation. Corticosteroids were administered according to local center practice. The first dose of study drug was administered within 24 hr after transplantation. From day 5, CsA and everolimus dose adjustments were made based on trough levels. Study-drug interruptions were permitted during antibody treatment for rejection episodes. A minimum of 30 days of CMV prophylaxis was mandatory for CMV donor-positive/recipient-negative transplants. Treatment with ganciclovir, CMV hyperimmunoglobulin, acyclovir, or valacyclovir was permitted and administered according to local practice. Pneumocystis carinii pneumonia prophylaxis was initiated when oral medication was tolerated and continued for the first year of the study. Pentamidine inhalation or dapsone was used by patients unable to tolerate trimethoprim-sulfamethoxazole.

Objectives at 24 months included comparisons of the incidence of graft loss, death, or loss to follow-up, primary composite efficacy endpoint, treated BPAR, premature study discontinuation, AEs, study treatment discontinuation, assessment of renal function using serum creatinine, and eGFR calculated using the Nankivell and MDRD formulas. These comparisons were not noninferiority as per the protocol.

Inclusion and Exclusion Criteria

Patients were eligible if they met the following criteria: aged 18–70 years undergoing primary kidney transplantation, having provided written consent to participate in the study, and, if female, must have had a negative pregnancy test before randomization. Key exclusion criteria included kidneys donated after cardiac death or with a cold ischemia time >40 hr; donor age >65 years; recipients of a previous organ/tissue transplant or of multiorgan, ABO-incompatible, positive T-cell crossmatch, or human leukocyte antigen–identical living related-donor transplants; or most recent anti–human leukocyte antigen class I panel reactive antibodies >20% by a complement-dependent cytotoxicity–based assay or >50% by flow cytometry or enzyme-linked immunosorbent assay.

Efficacy

The main efficacy objective (to demonstrate that at least one of the everolimus treatment regimens was noninferior with respect to primary efficacy failure to the MPA treatment regimen at 12 months) has been reported (9). Comparisons at 24 months were not noninferiority, as per the protocol. Efficacy outcomes assessed at 24 months included the incidence of the primary composite efficacy endpoint (treated BPAR episodes, graft loss, death, or loss to follow-up) and its components. 95% CIs for the differences in composite efficacy failure rates between the everolimus and the MPA groups were calculated over the 24-month study period. Loss to follow-up was defined as a patient who did not experience treated BPAR, graft loss, or death and whose last day of contact was before day 631 (the lower limit of the month 24 visit window). Allograft core biopsies were performed for all patients suspected of having acute rejection within 48 hr. Histologic interpretation was performed by local pathologists according to Banff criteria (18); pathologists were blinded to the patient’s treatment.

Safety

The main safety objective (to demonstrate that noninferior renal function was achieved in the everolimus treatment groups compared with the MPA treatment group at 12 months after transplantation) has been reported (9). Comparisons at 24 months were not noninferiority, as per the protocol. Renal function assessments at 24 months were determined using serum creatinine and eGFR derived from the Nankivell (19) and MDRD formulas (20). Renal function was also assessed at each study visit using Nankivell and MDRD formulas, serum creatinine, and calculated creatinine clearance (Cockcroft–Gault). Last, renal function was categorized using the NKF criteria for chronic kidney disease stage 3 (eGFR 30–59 mL/min/1.73 m2) and stage 4 (eGFR 15–29 mL/min/1.73 m2) (21).

Safety objectives at 24 months consisted of comparisons of the incidences of premature study discontinuation, study treatment discontinuation, and AEs; none of these were tested for noninferiority, as per the protocol. The incidence of AEs, serious AEs, and AEs leading to discontinuation was assessed throughout the 24-month study. Clinical laboratory measurements (biochemistry, hematology, urinalysis, and endocrinology) were also used to assess safety. Information on any MACE was reported on a MACE-specific case report/record form. Events were predefined and included acute myocardial infarction, congestive heart failure, percutaneous coronary intervention, coronary artery bypass graft, automatic internal cardiac defibrillator, cerebrovascular accident, and peripheral vascular disease.

Definitions used in this study are as follows. CMV infection: Medical Dictionary for Regulatory Activities preferred term “cytomegalovirus infection”; CMV syndrome: fever for 2 days, neutropenia, leukopenia, and viral syndrome; CMV disease: organ involvement; and NODM: diabetes reported as an AE >14 days after the date of transplantation, or a random glucose ≥11 mmol/L (200 mg/dL) after 14 days of transplantation, or diabetes recorded as the reason for posttransplantation use of a medication classed as “used in diabetes” by the Anatomical Therapeutic Chemical classification system, after 14 days of transplantation, and lasting for 14 days in patients who were not diabetic before transplantation. Patients with elevated glucose levels that resolved within 14 days were excluded.

Visit windows for the 24-month analysis were defined to avoid gaps or overlaps between the visits and so that all observations, including those collected at unscheduled visits, could be used. Visit windows for the month 12 data in this article are therefore extended to day 450, that is, the midpoint between months 12 and 18, and different from those in the published 12-month article, which were only up to the month 12 visit.

Statistical Analyses

Efficacy analyses were conducted on the intent-to-treat (ITT) population (all randomized patients). For the difference in event rates between the treatment groups, 95% CIs were calculated by the simple proportion estimate for rates with asymptotic normal distribution. Kaplan–Meier analyses were used to estimate the probability of experiencing an event, and log-rank tests were used to compare the time to event between treatment groups at months 12 and 24 (ITT population). On-treatment analyses consisted of assessments obtained on and after day 1 but no later than 2 days after the discontinuation of randomized study medication.

For renal function, the main analysis compared mean eGFR at 24 months using t distribution-based, two-sided 95% and 97.5% CI for the difference in mean eGFR between the everolimus and the MPA groups on the ITT population. Missing month 24 GFR values were imputed as follows: patients who lost their graft were assigned a value of zero for their month 24 GFR value; for all other patients with a missing month 24 GFR value, the last observation was carried forward. Other renal function analyses at 24 months were conducted without imputation on the ITT population using the Wilcoxon rank-sum test and stratified rates according to NKF categories.

Safety analyses were performed in all patients who received at least one dose of study drug and had ≥1 postbaseline safety assessment (safety population).

Sample Size Calculation

The sample size calculation was based on the assumption that efficacy failure rates at month 12 for the everolimus and MPA groups were 19% and 20%, respectively. The noninferiority margin was set at 10%. To control for multiple comparisons, the two-sided significance level was set at 0.025. Based on these assumptions, a sample size of 825 patients (275 per group) was calculated to have an 84% power to demonstrate that everolimus was not more than 10% inferior to MPA with respect to the 12-month composite efficacy failure rate.

ACKNOWLEDGMENTS

The authors thank the study investigators and coordinators for their hard work in making this study possible. Study investigators: Argentina: P. Novoa, R. Schiavelli, and L. Toselli; Australia: S. Campbell, S. Chadban, B. Hutchinson, J. Kanellis, P. O’Connell, B. Pussell, G. Russ, and R. Walker; Brazil: D. Carvalho, V. Garcia, L. Soares, and H. Tedesco Silva; Canada: M. Walsh; Hong Kong: C.S. Li; Italy: A. Albertazzi, M. Carmellini, G. Civati, G. Colussi, and F. Schena; Korea: H. Duck Jong, S.J. Kim, Y.H. Kim, Y.L. Kim, Y.S. Kim, and I.S. Moon; New Zealand: H. Pilmore; Slovakia: E. Lackova and R. Roland; Singapore: T. Kee and A. Vathsala; South Africa: S. Naicker; Sweden: G. Tufveson; Taiwan: P.H. Lee; Turkey: E. Akin, K. Keven, and A. Uslu; United Kingdom: Y. Magdi, H. Riad, and J. Pattison; United States of America: S. Abul-Ezz, E. Alfrey, K. Andreoni, M. Aaronson, P. Baliga, Y. Becker, P. Bolin, L. Chan, D.M. Cibrik, M. Cooper, A. Cotterell, C. Foster, C. Franklin, S. Jensik, T.D. Johnston, B. Kahan, D. Katz, D. Kim, M. Kumar, P.C. Kuo, J. Leone, M. Levy, B. Marder, B. Mistry, S. Mulgaonkar, L.L. Mulloy, T. O’Connor, P.T. Pham, K. Rice, V. Scantlebury, B. Sankari, R. Santella, H. Shidban, F. Shihab, D. Slakey, R.B. Stevens, J.R. Thistlewaite, J.D. Welchel, C.T. Van Buren, N. Youssef, C. Zayas, and G. Zibari.

REFERENCES

1. Halloran PF. Immunosuppressive drugs for kidney transplantation. N Engl J Med 2004; 351: 2715.
2. Jardine AG. Assessing the relative risk of cardiovascular disease among renal transplant patients receiving tacrolimus or cyclosporine. Transpl Int 2005; 18: 379.
3. Kramer BK, Zulke C, Kammerl MC, et al.. Cardiovascular risk factors and estimated risk for CAD in a randomized trial comparing calcineurin inhibitors in renal transplantation. Am J Transplant 2003; 3: 982.
4. Meier-Kriesche HU, Schold JD, Srinivas TR, et al.. Lack of improvement in renal allograft survival despite a marked decrease in acute rejection rates over the most recent era. Am J Transplant 2004; 4: 378.
5. Chapman JR. Clinical renal transplantation: where are we now, what are our key challenges? Transplant Proc 2010; 42: S3.
6. Buchler M, Caillard S, Barbier S, et al.. Sirolimus versus cyclosporine in kidney recipients receiving thymoglobulin, mycophenolate mofetil and a 6-month course of steroids. Am J Transplant 2007; 7: 2522.
7. Larson TS, Dean PG, Stegall MD, et al.. Complete avoidance of calcineurin inhibitors in renal transplantation: a randomized trial comparing sirolimus and tacrolimus. Am J Transplant 2006; 6: 514.
8. Budde K, Bosmans JL, Sennesael J, et al.. Reduced-exposure cyclosporine is safe and efficacious in de novo renal transplant recipients treated with enteric-coated mycophenolic acid and basiliximab. Clin Nephrol 2007; 67: 164.
9. Tedesco-Silva H Jr., Cibrik D, Johnston T, et al.. Everolimus plus reduced-exposure CsA versus mycophenolic acid plus standard-exposure CsA in renal-transplant recipients. Am J Transplant 2010; 10: 1401.
10. Budde K, Becker T, Arns W, et al.. Everolimus-based, calcineurin-inhibitor-free regimen in recipients of de-novo kidney transplants: an open-label, randomised, controlled trial. Lancet 2011; 377: 837.
11. Tanaka T, Kyo M, Kokado Y, et al.. Correlation between the Banff 97 classification of renal allograft biopsies and clinical outcome. Transpl Int 2004; 17: 59.
12. Vereerstraeten P, Abramowicz D, De PL, et al.. Absence of deleterious effect on long-term kidney graft survival of rejection episodes with complete functional recovery. Transplantation 1997; 63: 1739.
13. Salvadori M, Rosati A, Bock A, et al.. Estimated one-year glomerular filtration rate is the best predictor of long-term graft function following renal transplant. Transplantation 2006; 81: 202.
14. Helal I, Abderrahim E, Ben HF, et al.. The first year renal function as a predictor of long-term graft survival after kidney transplantation. Transplant Proc 2009; 41: 648.
15. Resende L, Guerra J, Santana A, et al.. First year renal function as a predictor of kidney allograft outcome. Transplant Proc 2009; 41: 846.
16. Meier-Kriesche HU, Baliga R, Kaplan B. Decreased renal function is a strong risk factor for cardiovascular death after renal transplantation. Transplantation 2003; 75: 1291.
17. Novartis Pharma AG. Data on file. 2009.
18. Racusen LC, Colvin RB, Solez K, et al.. Antibody-mediated rejection criteria—an addition to the Banff 97 classification of renal allograft rejection. Am J Transplant 2003; 3: 708.
19. Nankivell BJ, Gruenewald SM, Allen RD, et al.. Predicting glomerular filtration rate after kidney transplantation. Transplantation 1995; 59: 1683.
20. Levey AS, Bosch JP, Lewis JB, et al.. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med 1999; 130: 461.
21. Levey AS, Coresh J, Balk E, et al.. National Kidney Foundation practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Ann Intern Med 2003; 139: 137.
Keywords:

Calcineurin inhibitor toxicity; Cyclosporine; Everolimus; Renal function; Renal transplantation

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