Pharmacokinetics of Once-Daily Extended-Release Tacrolimus Tablets Versus Twice-Daily Capsules in De Novo Liver Transplant.

The pharmacokinetics of once-daily extended-release tacrolimus tablets (LCPT) in de novo liver transplantation have not been previously reported. In this phase II, randomized, open-label study, de novo liver transplant recipients were randomized to LCPT 0.07-0.13 mg/kg/day (taken once daily; n = 29) or twice-daily immediate-release tacrolimus capsules (IR-Tac) at 0.10-0.15 mg/kg/day (divided twice daily; n = 29). Subsequent doses of both drugs were adjusted to maintain tacrolimus trough concentrations of 5 to 20 ng/mL through day 90, and 5-15 ng/mL thereafter. Twenty-four-hour pharmacokinetic profiles were obtained on days 1, 7, and 14, with trough concentration and efficacy/safety monitoring through year 1. Similar proportions of patients in both groups achieved therapeutic trough concentrations on days 7 and 14 (day 7: LCPT = 78%, IR-Tac = 75%; day 14: LCPT = 86%, IR-Tac = 91%) as well as similar systemic and peak exposure. There was a robust correlation between drug concentration at time 0 and area under the concentration-time curve for both LCPT and IR-Tac (respectively, day 7: r = 0.86 and 0.79; day 14: r = 0.93 and 0.86; P < .0001 for all). Dose adjustments during days 1 to 14 were frequent. Thirty-five patients completed the extended-use period. No significant differences in adverse events were seen between groups. Incidence of biopsy-proven acute rejection (LCPT = 6 and IR-Tac = 4) was similar on day 360. Between formulations, overall exposure was similar at 1 week after transplant with the characteristic delayed-release pharmacokinetic profile of LCPT demonstrated in this novel population. These data support further investigation of the safety and efficacy of LCPT in de novo liver transplantation.

Multicenter evaluation of efficacy and safety of low-dose versus high-dose valganciclovir for prevention of cytomegalovirus disease in donor and recipient positive (D+/R+) renal transplant recipients.

BACKGROUND: The cytomegalovirus (CMV) donor-positive/recipient-positive (D+/R+) population is the largest proportion of renal transplant recipients (RTR). Guidelines for prevention of CMV in the intermediate-risk D+/R+ population include prophylaxis with valganciclovir (VGCV) 900 mg/day for 3 months. This study is the first head-to-head analysis, to our knowledge, comparing the efficacy and safety CMV prophylaxis of VGCV 450 vs 900 mg/day for 3 months in D+/R+ RTR. METHODS: A multicenter, retrospective analysis evaluated 478 adult RTR between January 2008 and October 2011. Study participants received VGCV 450 mg/day (Group 1; n=398) or 900 mg/day (Group 2; n=89)×3 months for CMV prophylaxis. All VGCV was adjusted for renal function. All groups included in this study received study-approved induction and maintenance immunosuppression regimens. The primary endpoint was incidence of CMV disease at 12 months. RESULTS: The rates of graft loss, patient survival, T-cell and/or antibody-mediated rejection, hematological adverse events, opportunistic infections, and early VGCV discontinuation were evaluated. Patient demographics were comparable, but had significant differences in ethnicity and donor type between the groups. CONCLUSION: The occurrence of CMV disease at 12 months was similar between the groups (3.5% vs 3.4%; P=1.000). Log-rank test found no statistically significant difference in the time to development of CMV between the 2 groups (P=.939).

Early corticosteroid withdrawal in the real world: a long-term analysis of kidney transplant recipients from the Mycophenolic Acid Observational Renal Transplant Registry.

BACKGROUND: Prospective, long-term data on corticosteroid withdrawal (CSW) versus corticosteroid continuation (CSC) following kidney transplantation are scarce. MATERIAL/METHODS: The Mycophenolic Renal Transplant (MORE) Registry was a prospective, observational study of de novo kidney transplant patients receiving mycophenolic acid (MPA) and standard of care. Adult patients receiving tacrolimus and enteric-coated mycophenolate sodium (EC-MPS) or mycophenolate mofetil (MMF) at time of transplant were analyzed to 4 years according to CSW by month 3 (n=363) or CSC (n=509). RESULTS: In the CSW and CSC groups, 3.3% and 13.0% had undergone retransplantation (p<0.001), 89.9% and 77.0% had panel reactive antibodies <30% (p<0.001), and 72.5% and 87.2% received pretransplant dialysis (p<0.001), respectively. Rabbit antithymocyte induction was used in 62.3% of CSW patients and 58.6% of CSC patients (p=0.015), and alemtuzumab in 23.7% and 4.7%, respectively (p=0.002). At all time points to 3 years post-transplant, significantly fewer CSW patients were maintained on the full recommended dose of MPA versus CSC patients. Biopsy-proven acute rejection occurred in 10.1% and 14.3% of CSW and CSC patients (p=0.12), graft survival was 96.9% versus 93.7% (p=0.030), and patient survival was 95.6% versus 95.0% (p=0.65), respectively. Adverse events were similar except for leukopenia (CSW 60.6%, CSC 29.9%; p<0.001) and neutropenia (CSW 17.4%, CSC 11.4%; p=0.013), with infections in 24.8% and 30.8% of CSW and CSC patients, respectively (p=0.057). CONCLUSIONS: CSW patients were less likely to receive the full dose of MPA than CSC patients, possibly due to induction-related hematological toxicity. Graft survival to 4 years post-transplant was superior in CSW patients.

Does reduction in mycophenolic acid dose compromise efficacy regardless of tacrolimus exposure level? An analysis of prospective data from the Mycophenolic Renal Transplant (MORE) Registry.

Prospective data are lacking concerning the effect of reduced mycophenolic acid (MPA) dosing on efficacy and the influence of concomitant tacrolimus exposure. The Mycophenolic Renal Transplant (MORE) Registry is a prospective, observational study of de novo kidney transplant patients receiving MPA therapy under routine management. The effect of MPA dose reduction, interruption, or discontinuation (dose changes) was assessed in 870 tacrolimus-treated patients: 375 (43.1%) reduced tacrolimus (≤ 7 ng/mL at baseline) and 495 (56.9%) standard tacrolimus (>7 ng/mL); enteric-coated mycophenolate sodium 589 (67.7%) and mycophenolate mofetil 281 (32.3%). During baseline to month 1, months 1-3, months 3-6, and months 6-12, 9.3% (78/838), 16.6% (132/794), 20.7% (145/701), and 13.1% (70/535) patients, respectively, required MPA dose changes. These patients experienced an increased risk of biopsy-proven acute rejection at one yr with tacrolimus exposure either included in the model (hazard ratio [HR] 2.60, 95% CI 1.28-5.29, p = 0.008) or excluded (HR 2.58, 95% CI 1.28-5.23, p = 0.008). MPA dose changes were significantly associated with one yr graft failure when tacrolimus exposure was included (HR 2.23; 95% CI 1.01-4.89, p = 0.047) but not when tacrolimus exposure was excluded (HR 2.16; 95% CI 0.99-4.79; p = 0.054). These results suggest that reducing or discontinuing MPA can adversely affect graft outcomes regardless of tacrolimus trough levels.

Association of mycophenolic acid dose with efficacy and safety events in kidney transplant patients receiving tacrolimus: an analysis of the Mycophenolic acid Observational REnal transplant registry.

BACKGROUND: Dose-finding studies for mycophenolic acid (MPA) in tacrolimus-treated kidney transplant patients are lacking. METHODS: Data from 901 de novo kidney transplant recipients enrolled in the prospective, non-interventional Mycophenolic acid Observational REnal (MORE) transplant registry were analyzed according to baseline daily MPA dose (<2000, 2000 or >2000 mg). RESULTS: The proportion of patients receiving 2000 and <2000 mg was 77.6% and 19.9% at baseline, 74.5% and 23.3% at month 1, 62.4% and 35.5% at month 3, 48.5% and 50.2% at month 6, and 44.1% and 55.2% at month 12. More patients were maintained on 2000 mg with enteric-coated mycophenolate sodium (EC-MPS) vs. mycophenolate mofetil (month 6, 52.7% vs. 43.0% [p=0.02]; month 12, 47.3% vs. 39.4% [p=0.08]). Multivariate modeling showed no significant effect of baseline MPA dose on 12-month risk of biopsy-proven acute rejection, graft loss or estimated GFR, or on safety events including MPA discontinuation other than a higher rate of gastrointestinal adverse events in patients with an initial MPA dose>2000 mg (p=0.029) vs. 2000 mg. CONCLUSIONS: These findings suggest that an initial MPA dose of <2000 mg does not compromise 12-month efficacy in tacrolimus-treated kidney transplants, but controlled trials are required and the lower threshold for MPA dose remains to be defined.