Wolfgang Arns

Everolimus in Patients with Autosomal Dominant Polycystic Kidney Disease

BACKGROUND Autosomal dominant polycystic kidney disease (ADPKD) is a slowly progressive hereditary disorder that usually leads to end-stage renal disease. Although the underlying gene mutations were identified several years ago, efficacious therapy to curtail cyst growth and prevent renal failure is not available. Experimental and observational studies suggest that the mammalian target of rapamycin (mTOR) pathway plays a critical role in cyst growth. METHODS In this 2-year, double-blind trial, we randomly assigned 433 patients with ADPKD to receive either placebo or the mTOR inhibitor everolimus. The primary outcome was the change in total kidney volume, as measured on magnetic resonance imaging, at 12 and 24 months. RESULTS Total kidney volume increased between baseline and 1 year by 102 ml in the everolimus group, versus 157 ml in the placebo group (P=0.02) and between baseline and 2 years by 230 ml and 301 ml, respectively (P=0.06). Cyst volume increased by 76 ml in the everolimus group and 98 ml in the placebo group after 1 year (P=0.27) and by 181 ml and 215 ml, respectively, after 2 years (P=0.28). Parenchymal volume increased by 26 ml in the everolimus group and 62 ml in the placebo group after 1 year (P=0.003) and by 56 ml and 93 ml, respectively, after 2 years (P=0.11). The mean decrement in the estimated glomerular filtration rate after 24 months was 8.9 ml per minute per 1.73 m2 of body-surface area in the everolimus group versus 7.7 ml per minute in the placebo group (P=0.15). Drug-specific adverse events were more common in the everolimus group; the rate of infection was similar in the two groups. CONCLUSIONS Within the 2-year study period,as compared with placebo, everolimus slowed the increase in total kidney volume of patients with ADPKD but did not slow the progression of renal impairment [corrected]. (Funded by Novartis; EudraCT number, 2006-001485-16; ClinicalTrials.gov number, NCT00414440.)

Enteric-coated mycophenolate sodium is therapeutically equivalent to mycophenolate mofetil in de novo renal transplant patients.

The introduction of mycophenolate mofetil (MMF) represented a major advance in transplant medicine, although optimal use may be limited by gastrointestinal (GI) side‐effects. An enteric‐coated formulation of mycophenolate sodium (EC‐MPS; myfortic®) has been developed with the aim of improving the upper GI tolerability of mycophenolic acid. Therapeutic equivalence of EC‐MPS (720 mg b.i.d.) and MMF (1000 mg MMF b.i.d.), with concomitant cyclosporine microemulsion (Neoral®) and corticosteroids, was assessed in 423 de novo kidney transplant patients recruited to a 12‐month, double‐blind study. Efficacy failure (biopsy‐proven acute rejection [BPAR], graft loss, death or loss to follow up) at 6 months (EC‐MPS 25.8% vs. MMF 26.2%; 95% CI: [−8.7, +8.0]) demonstrated therapeutic equivalence. At 12 months, the incidence of BPAR, graft loss or death was 26.3% and 28.1%, and of BPAR alone was 22.5% and 24.3% for EC‐MPS and MMF, respectively. Among those with BPAR, the incidence of severe acute rejection was 2.1% with EC‐MPS and 9.8% with MMF (p = ns). The safety profile and incidence of GI adverse events were similar for both groups. Within 12 months, 15.0% of EC‐MPS patients and 19.5% of MMF patients required dose changes for GI adverse events (p = ns). Enteric‐coated‐MPS 720 mg b.i.d. is therapeutically equivalent to MMF 1000 mg b.i.d. with a comparable safety profile.

Everolimus-based, calcineurin-inhibitor-free regimen in recipients of de-novo kidney transplants: an open-label, randomised, controlled trial

BACKGROUND Non-nephrotoxic immunosuppressive strategies that allow reduction of calcineurin-inhibitor exposure without compromising safety or efficacy remain a goal in kidney transplantation. Immunosuppression based on the mammalian-target-of-rapamycin inhibitor everolimus was assessed as a strategy for elimination of calcineurin-inhibitor exposure and optimisation of renal-graft function while maintaining efficacy. METHODS In the ZEUS multicentre, open-label study, 503 patients (aged 18-65 years) who had received de-novo kidney transplants were enrolled. After initial treatment with ciclosporin, based on trough concentrations, and enteric-coated mycophenolate sodium (1440 mg/day, orally), corticosteroids (≥5 mg/day prednisolone or equivalent, orally), and basiliximab induction (20 mg, intravenously, on day 0 [2 h before transplantation], and on day 4), 300 (60%) patients were randomly assigned at 4·5 months in a 1:1 ratio to undergo calcineurin-inhibitor elimination (everolimus-based regimen that was based on trough concentrations [6-10 ng/mL] and enteric-coated mycophenolate sodium [1440 mg/day] with corticosteroids), or continue standard ciclosporin-based treatment. Randomisation was done by use of a central, validated system that automated the random assignment of treatment groups to randomisation numbers. The primary objective was to show better renal function (glomerular filtration rate [GFR]; Nankivell formula) with the calcineurin-inhibitor-free everolimus regimen at 12 months after transplantation. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00154310. FINDINGS 118 (76%) of 155 everolimus-treated patients and 117 (81%) of 145 ciclosporin-treated patients completed treatment with study drug up to 12 months after transplantation. At this timepoint, the everolimus regimen was associated with a significant improvement in GFR versus the ciclosporin regimen (71·8 mL/min per 1·73 m(2) vs 61·9 mL/min per 1·73 m(2), respectively; mean difference 9·8 mL/min per 1·73 m(2), 95% CI -12·2 to -7·5). Rates of biopsy-proven acute rejection were higher in the everolimus group than in the ciclosporin group after randomisation (15 [10%] of 154 vs five [3%] of 146; p = 0·036), but similar for the full study period (23 [15%] vs 22 [15%]). Compared with the ciclosporin regimen, higher mean lipid concentrations, slightly increased urinary protein excretion, and lower haemoglobin concentrations were noted with the everolimus regimen; thrombocytopenia, aphthous stomatitis, and diarrhoea also occurred more often in the everolimus group. A higher incidence of hyperuricaemia was noted with ciclosporin. INTERPRETATION Early elimination of calcineurin inhibitor by use of everolimus-based immunosuppression improved renal function at 12 months while maintaining efficacy and safety, indicating that this strategy may facilitate improved long-term outcomes in selected patients. FUNDING Novartis Pharma.

Patient-reported gastrointestinal symptom burden and health-related quality of life following conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium.

Background. The benefit of converting renal transplant recipients with gastrointestinal (GI) complaints from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) has not been evaluated using patient-reported outcomes. Methods. A multicenter, open-label, prospective study was undertaken in MMF-treated renal transplant patients. Patients experiencing GI complaints were converted to equimolar EC-MPS (Cohort A). Patients without GI complaints remained on MMF (Cohort B). At baseline and Visit 2 (4–6 weeks postbaseline), patients completed the Gastrointestinal Symptom Rating Scale (GSRS), Gastrointestinal Quality of Life Index (GIQLI) and Psychological General Well-being Index (PGWBI). At Visit 2, patients and physicians completed the Overall Treatment Effect (OTE) scale for GI symptoms. Additionally, patients completed the OTE for health-related quality of life (HRQoL). Minimal important difference (MID) was calculated for GSRS and GIQLI based on patients’ and physicians’ OTE evaluation. Results. Of 328 patients enrolled (i.e. the intent-to-treat and safety populations), 278 formed the per-protocol population (Cohort A, n=177; Cohort B, n=101). At baseline, Cohort A had significantly worse scores on all GSRS, GIQLI and PGWBI subscales compared to Cohort B (all P<0.0001). All GSRS, GIQLI and PGWBI subscale scores improved significantly in Cohort A between baseline and Visit 2 (all P<0.0001). Mean improvements in all GSRS subscales and most GIQLI subscores exceeded the calculated MID. GSRS, GIQLI and PGWBI subscales remained stable in Cohort B. Conclusion. This first exploratory study indicates that converting patients with mild, moderate or severe GI complaints from MMF to EC-MPS significantly reduces GI-related symptom burden and improves patient functioning and well-being.

Enteric-coated mycophenolate sodium delivers bioequivalent MPA exposure compared with mycophenolate mofetil

Abstract:  Mycophenolic acid (MPA), the active moiety of mycophenolate mofetil (MMF), is routinely used as an adjunct immunosuppressant therapy in renal transplantation. Although highly effective, MMF therapy is associated with significant gastrointestinal adverse effects. Enteric‐coated mycophenolate sodium (EC‐MPS) is an advanced formulation delivering MPA. The enteric coat dissolves at pH > 5 allowing for MPA delivery in the small intestine. A single‐center, open‐label, randomized, three‐way crossover study of 24 stable Caucasian renal transplant patients receiving cyclosporine‐based immunosuppression, compared the relative bioavailability of two EC‐MPS doses (640 and 720 mg) with MMF (1000 mg). Both EC‐MPS doses delivered bioequivalent mean MPA exposure (AUC0−∞) compared with 1000 mg MMF: 60.7 μg h/mL for 640 mg EC‐MPS, 66.5 μg h/mL for 720 mg EC‐MPS, and 63.7 μg h/mL for 1000 mg MMF. Median tmax was significantly delayed for both EC‐MPS doses compared with MMF (2.0 h vs. 0.75 h, respectively; p < 0.01), consistent with a functional enteric coating of EC‐MPS. Furthermore, both EC‐MPS doses were bioequivalent to 1000 mg MMF for AUC and Cmax for mycophenolic acid glucuronide. All three treatments were well tolerated. The EC‐MPS 720 mg dose most closely approximated the MPA exposure of 1000 mg MMF and was selected for subsequent phase III studies.

Sotrastaurin, a novel small molecule inhibiting protein-kinase C: Randomized phase II study in renal transplant recipients

Sotrastaurin, a selective protein‐kinase‐C inhibitor, blocks early T‐cell activation through a calcineurin‐independent mechanism. In this study, de novo renal transplant recipients with immediate graft function were randomized 1:2 to tacrolimus (control, n = 44) or sotrastaurin (300 mg b.i.d.; n = 81). All patients received basiliximab, mycophenolic acid (MPA) and steroids. The primary endpoint was the composite of treated biopsy‐proven acute rejection (BPAR), graft loss, death or lost to follow‐up at month 3. The main safety assessment was estimated glomerular filtration rate (eGFR); modification of diet in renal disease (MDRD) at month 3. Composite efficacy failure at month 3 was higher for the sotrastaurin versus control regimen (25.7% vs. 4.5%, p = 0.001), driven by higher BPAR rates (23.6% vs. 4.5%, p = 0.003), which led to early study termination. Median (± standard deviation [SD]) eGFR was higher for sotrastaurin versus control at all timepoints from day 7 (month 3: 59.0 ± 22.3 vs. 49.5 ± 17.7 mL/min/1.73 m2, p = 0.006). The most common adverse events were gastrointestinal disorders (control: 63.6%; sotrastaurin: 88.9%) which led to study‐medication discontinuation in two sotrastaurin patients. This study demonstrated a lower degree of efficacy but better renal function with the calcineurin‐inhibitor‐free regimen of sotrastaurin+MPA versus the tacrolimus‐based control. Ongoing studies are evaluating alternative sotrastaurin regimens.

Five-year outcomes in kidney transplant patients converted from cyclosporine to everolimus: the randomized ZEUS study.

ZEUS study was an open‐label, 12‐month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five‐year follow‐up data were available for 245/269 patients (91.1%) who completed the core 12‐month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m2 with everolimus versus 60.9 mL/min/1.73 m2 with CsA; the mean difference was 5.3 mL/min/1.73 m2 in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent‐to‐treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m2 (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy‐proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long‐term graft function.

Conversion from cyclosporine to everolimus at 4.5 months posttransplant: 3-year results from the randomized ZEUS study.

The long‐term effect of conversion from calcineurin inhibitor (CNI) therapy to an mTOR inhibitor requires clarification. Following completion of the 12‐month, open‐label, multicenter ZEUS study, in which 300 kidney transplant recipients were randomized to continue cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant, outcomes were assessed at month 36 (n = 284; 94.7%). CNI therapy was reintroduced in 28.4% of everolimus patients by month 36. The primary efficacy endpoint, estimated glomerular filtration rate (Nankivell, ANCOVA) was significantly higher with everolimus versus the CsA group at month 24 (7.6 mL/min/1.73 m2, 95%CI 4.3, 11.0 mL/min/1.73 m2; p < 0.001) and month 36 (7.5 mL/min/1.73 m2, 95%CI 3.6, 11.4 mL/min/1.73 m2; p < 0.001). The incidence of biopsy‐proven acute rejection from randomization to month 36 was 13.0% in the everolimus arm and 4.8% in the CsA arm (p = 0.015). Patient and graft survival, as well as incidences of malignancy, severe infections and hospitalization, were similar between groups. Kidney transplant patients who are converted from CsA to everolimus at month 4.5 and who remain on everolimus thereafter may achieve a significant improvement in renal function that is maintained to 3 years. There was a significantly higher rate of rejection in the everolimus arm but this did not exert a deleterious effect by 3 years posttransplant.

Conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in maintenance renal transplant recipients receiving tacrolimus: clinical, pharmacokinetic, and pharmacodynamic outcomes.

Background. Mycophenolic acid (MPA) pharmacokinetics using the mycophenolate mofetil (MMF) formulation are known to differ between patients receiving tacrolimus or cyclosporine, but only limited data exist concerning concomitant use of tacrolimus and enteric-coated mycophenolate sodium (EC-MPS). Methods. In this six-month, multicenter, open-label, single-arm trial, 63 maintenance renal transplant patients receiving tacrolimus were converted from mycophenolate mofetil (MMF) to EC-MPS. Results. MPA concentration-time profiles in 21 patients showed that MPA exposure was similar with MMF or EC-MPS (mean area under the curve 39.9±11.6 &mgr;g×h/mL versus 43.7±17.4 &mgr;g×h/mL at day 14 post-conversion). Median time to peak concentration was 0.5 hr with MMF and 1.5 hr with EC-MPS. Inosine monophosphate dehydrogenase (IMPDH) activity was almost identical: area under the enzyme activity time curve (AEC) was 124.2±32.0 nmol×h/mg prot/h with MMF and 130.3±36.6 nmol×h/mg prot/h with EC-MPS at 14 days post-conversion; average daytime IMPDH activity was 10.3±2.7 nmol/h/mg protein and 10.9±2.7 nmol/h/mg protein, respectively. Maximal daytime inhibition of IMPDH activity was 67% with MMF and 62% with EC-MPS at day 14. One patient (1.6%) experienced mild biopsy-proven acute rejection. No graft losses or deaths occurred. Renal function remained stable (mean calculated creatinine clearance 70.6±26.8 mL/min with MMF and 68.8±25.4 mL/min six months post-conversion). Adverse events or infections with a suspected relation to EC-MPS occurred in 12 patients (19%). Four patients discontinued EC-MPS due to adverse events or infections. Conclusions. MMF and EC-MPS are associated with similar MPA exposure and equivalent pharmacodynamic effect. Conversion of tacrolimus-treated maintenance renal transplant patients from MMF to EC-MPS is safe and well-tolerated and does not compromise therapeutic efficacy.

Plasma concentrations of mycophenolic acid acyl glucuronide are not associated with diarrhea in renal transplant recipients

The aim of this study was to determine whether plasma concentrations of the acyl (AcMPAG) and phenolic (MPAG) glucuronide metabolites of mycophenolic acid (MPA) were related to diarrhoea in renal transplant patients on mycophenolate mofetil (MMF) with cyclosporine (CsA) or tacrolimus (TCL). Blood samples (0, 30, 120 min) were taken at days 3, 10, week 4, months 3, 6 and 12 for determination of MPA, MPAG and AcMPAG. MPA‐AUC was estimated using validated algorithms. Two hour AUCs were calculated for MPAG and AcMPAG. Immunosuppressive therapy consisted of CsA/MMF (n= 110) and of TCL/MMF (n= 180). In 70/290 (24%) patients 86 episodes of diarrhoea were recorded during 12 months. Significantly more patients on TCL (31.1%) suffered from diarrhea compared to CsA (12.7%). MMF dose, MPA‐AUC and the 2 h AUCs of MPAG and AcMPAG did not differ between patients with and without diarrhoea. Plasma AcMPAG and MPAG concentrations were substantially higher in patients on CsA compared with TCL, while MPA‐AUC was lower in the former group. These data support the concept that CsA inhibits the biliary excretion of MPAG and AcMPAG, thereby potentially reducing the risk of intestinal injury through enterohepatic recycling of MPA and its metabolites.