Association between CYP3A4, CYP3A5 and ABCB1 genotype and tacrolimus treatment outcomes among allogeneic HSCT patients.

Aim: Successful treatment with tacrolimus to prevent graft versus host disease (GVHD) and minimize tacrolimus-related toxicities among allogeneic hematopoietic cell transplantation (alloHCT) recipients is contingent upon quickly achieving and maintaining concentrations within a narrow therapeutic range. The primary objective was to investigate associations between CYP3A4, CYP3A5 or ABCB1 genotype and the proportion of patients that attained an initial tacrolimus goal concentration following initiation of intravenous (iv.) and conversion to oral administration. Materials & methods: We retrospectively evaluated 86 patients who underwent HLA-matched (8/8) related donor alloHCT and were prescribed a tacrolimus-based regimen for GVHD prophylaxis. Results & conclusion: The findings of the present study suggests that CYP3A5 genotype may impact attainment of initial therapeutic tacrolimus concentrations with oral administration in alloHCT recipients.

Mycophenolate mofetil versus methotrexate for prevention of graft-versus-host disease in people receiving allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HCT) is associated with improved outcomes for people with various hematologic diseases; however, the morbidity and mortality resulting from acute and subsequently chronic graft-versus-host disease (GVHD) pose a serious challenge to wider applicability of allo-HCT. Intravenous methotrexate in combination with a calcineurin inhibitor, cyclosporine or tacrolimus, is a widely used regimen for the prophylaxis of acute GVHD, but the administration of methotrexate is associated with a number of adverse events. Mycophenolate mofetil, in combination with a calcineurin inhibitor, has been used extensively in people undergoing allo-HCT. Conflicting results regarding various clinical outcomes following allo-HCT have been observed when comparing mycophenolate mofetil-based regimens against methotrexate-based regimens for acute GVHD prophylaxis. PRIMARY OBJECTIVE: to assess the effect of mycophenolate mofetil versus methotrexate for prevention of acute GVHD in people undergoing allo-HCT. SECONDARY OBJECTIVES: to evaluate the effect of mycophenolate mofetil versus methotrexate for overall survival, prevention of chronic GVHD, incidence of relapse, treatment-related harms, nonrelapse mortality, and quality of life. SEARCH METHODS: We searched Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE from inception to March 2014. We handsearched conference abstracts from the last two meetings (2011 and 2012) of relevant societies in the field. We searched ClinicalTrials.gov, Novartis clinical trials database (www.novctrd.com), Roche clinical trial protocol registry (www.roche-trials.com), Australian New Zealand Clinical Trials Registry (ANZCTR), and the metaRegister of Controlled Trials for ongoing trials. SELECTION CRITERIA: Two review authors independently reviewed all titles/abstracts and selected full-text articles for inclusion. We included all references that reported results of randomized controlled trials (RCTs) of mycophenolate mofetil versus methotrexate for the prophylaxis of GVHD among people undergoing allo-HCT in this review. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data on outcomes from all studies and compared prior to data entry and analysis. We expressed results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes and hazard ratios (HR) and 95% CIs for time-to-event outcomes. We pooled the individual study effects using the random-effects model. Estimates lower than one indicate that mycophenolate mofetil was favored over methotrexate. MAIN RESULTS: We included three trials enrolling 177 participants (174 participants analyzed). All participants in the trials by Keihl et al. and Bolwell et al. received cyclosporine while all participants enrolled in the trial by Perkins et al. received tacrolimus. However, the results did not differ by the type of calcineurin inhibitor employed (cyclosporine versus tacrolimus). There was no evidence for a difference between mycophenolate mofetil versus methotrexate for the outcomes of incidence of acute GVHD (RR 1.25; 95% CI 0.75 to 2.09; P value = 0.39, very low quality evidence), overall survival (HR 0.73; 95% CI 0.45 to 1.17; P value = 0.19, low-quality evidence), median days to neutrophil engraftment (HR 0.77; 95% CI 0.51 to 1.17; P value = 0.23, low-quality evidence), incidence of relapse (RR 0.84; 95% CI 0.52 to 1.38; P value = 0.50, low-quality evidence), non-relapse mortality (RR 1.21; 95% CI 0.62 to 2.36; P value = 0.57, low-quality evidence), and incidence of chronic GVHD (RR 0.92; 95% CI 0.65 to 1.30; P value = 0.62, low-quality evidence). There was low-quality evidence that mycophenolate mofetil compared with methotrexate improved platelet engraftment period (HR 0.87; 95% CI 0.81 to 0.93; P value < 0.0001, low-quality evidence). There was low-quality evidence that mycophenolate mofetil compared with methotrexate resulted in decreased incidence of severe mucositis (RR 0.48; 95% CI 0.32 to 0.73; P value = 0.0006, low-quality evidence), use of parenteral nutrition (RR 0.48; 95% CI 0.26 to 0.91; P value = 0.02, low-quality evidence), and medication for pain control (RR 0.76; 95% CI 0.63 to 0.91; P value = 0.002, low-quality evidence). Overall heterogeneity was not detected in the analysis except for the outcome of neutrophil engraftment. None of the included studies reported any outcomes related to quality of life. Overall quality of evidence was low. AUTHORS' CONCLUSIONS: The use of mycophenolate mofetil compared with methotrexate for primary prevention of GVHD seems to be associated with a more favorable toxicity profile, without an apparent compromise on disease relapse, transplant-associated mortality, or overall survival. The effects on incidence of GVHD between people receiving mycophenolate mofetil compared with people receiving methotrexate were uncertain. There is a need for additional high-quality RCTs to determine the optimal GVHD prevention strategy. Future studies should take into account a comprehensive view of clinical benefit, including measures of morbidity, symptom burden, and healthcare resource utilization associated with interventions.

Retrospective comparison of filgrastim plus plerixafor to other regimens for remobilization after primary mobilization failure: clinical and economic outcomes.

We performed a retrospective analysis to evaluate clinical and economic outcomes in patients receiving remobilization therapy after primary mobilization failure. Our primary endpoint was to compare filgrastim plus plerixafor to other regimens in their ability to collect a target cell dose of at least 2 million CD34+ cells/kg (cumulative). Of 96 consecutive patients who failed their primary mobilization therapy and in whom a second mobilization was attempted, remobilization consisted of filgrastim plus plerixafor (n = 38), filgrastim with or without sargramostim (n = 43), or chemotherapy plus filgrastim (n = 15), 84% of filgrastim/plerixafor patients were able to collect at least 2 million CD34+ cells/kg from both mobilizations, compared to 60% of patients mobilized with chemotherapy/filgrastim and 79% of the filgrastim ± sargramostim patients (P = 0.17). However, when combined with cells collected from the first mobilization, 53% of filgrastim/plerixafor patients reached the target of 2 million CD34+ cells in one apheresis, compared to 20% of those receiving chemotherapy/filgrastim and 28% of those receiving filgrastim ± sargramostim (P = 0.02). Resource utilization, mobilization drug costs, clinical care costs, and total costs were significantly different. We conclude that while filgrastim/plerixafor is the most efficient remobilization strategy, those clinical benefits may not translate into lower cost, especially when multiple days of plerixafor administration are required.

Maximally tolerated busulfan systemic exposure in combination with fludarabine as conditioning before allogeneic hematopoietic cell transplantation.

Systemic exposure to high-dose busulfan has been correlated with efficacy and toxicity after hematopoietic cell transplantation for malignancy. We used the area under the concentration-time curve (AUC) to prospectively determine the maximally tolerated systemic exposure to i.v. busulfan when given once daily after fludarabine administered at 40 mg/m(2) for 4 days. Three target AUC levels were planned: 6,000, 7,500, and 9,000 µM-min. Included were patients 16 to 65 years old, with a hematologic malignancy, an HLA A, B, or C, DRB1 8/8 or 7/8 matched donor, Karnofsky performance status ≥70%, and adequate organ function. For level 1 patients, i.v. busulfan doses 1 and 2 were 170 mg/m(2)/day, then doses 3 and 4 were adjusted based on first-dose pharmacokinetic modeling to achieve an average daily AUC of 6,000 µM-min. Doses 1 and 2 for the subsequent cohorts were based on the level 1 data: 180 mg/m(2)/day for AUC 7,500 µM-min (level 2) and 220 mg/m(2)/day for AUC 9,000 µM-min (level 3), with pharmacokinetic targeting for doses 3 and 4. Pharmacokinetic analysis after the last dose showed that 88% of the patients had been exposed to a mean AUC within 10% of the target. Forty patients were treated at level 1, 29 patients at level 2, and three patients at level 3. DLT was veno-occlusive disease of the liver, which occurred in none of 40 patients (0%) at level 1, two of 29 patients (7%) at level 2, and three of three patients (100%) at level 3. Dermatitis (P < .01) and pulmonary toxicity (P = .01) were also increased at higher AUC levels. Level 2 (7,500 µM-min × 4 days) was the maximally tolerated AUC. Within the confines of the trial's small sample size, there was no suggestion that escalating busulfan AUC from 6,000 to 7,500 µM-min × 4 days increased nonrelapse mortality. Assessment of the higher busulfan AUC on relapse prevention requires trials in patients with a homogeneous risk of relapse.

Phase I Study of Topotecan, Ifosfamide, and Etoposide (TIME) with autologous stem cell transplant in refractory cancer: pharmacokinetic and pharmacodynamic correlates.

PURPOSE: To determine the maximum tolerated dose (MTD) of topotecan in combination with ifosfamide, mesna, and etoposide (TIME), followed by autologous hematopoietic cell transplant (HCT), in patients with chemotherapy-refractory malignancies. EXPERIMENTAL DESIGN: Patients were treated with (in mg/m(2)/d) ifosfamide 3,333, mesna 3,333, and topotecan 3.3 to 28.3 during days -8 through -6 and etoposide 500 (days -5 through -3) followed by HCT on day 0. Once MTD was defined, we expanded this dosing cohort to include patients with high-risk lymphoma due to activity seen during dose escalation. Topotecan pharmacokinetic analyses were carried out, and topoisomerase I levels and activity were measured. RESULTS: The topotecan MTD in this regimen was 64 mg/m(2) (21.3 mg/m(2)/d). Mucositis was dose limiting and correlated with topotecan dose level and area under the curve (AUC). Dose level was also correlated with length of hospitalization, number of days of parenteral nutrition, and neutrophil and platelet engraftment. Topotecan AUC was significantly correlated with time to platelet recovery. The baseline peripheral blood mononuclear cell topoisomerase I level was found to be a significant positive predictor for overall and progression-free survival. Topotecan AUC was positively correlated with dose level, with a trend toward decreasing clearance with increasing dose. CONCLUSION: Topotecan can be a useful drug in the high-dose setting given its activity in some malignancies when given in standard dose. Pharmacokinetic monitoring may be a valuable tool for optimizing the use of topotecan and to avoid toxicity seen with high-systemic exposures. Baseline topoisomerase I levels may have an important role in predicting topotecan efficacy.