Prevention of Cytomegalovirus Reactivation in Haploidentical Stem Cell Transplantation.

Cytomegalovirus (CMV) infection can increase the morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Because of a higher degree of immunosuppression, haploidentical transplant recipients may be at an increased risk of viral infections, particularly CMV. We retrospectively analyzed 86 haploidentical HCT recipients at our institution to determine whether a more intensified antiviral strategy would reduce the incidence of CMV reactivation compared with a traditional antiviral prophylaxis regimen. According to practice changes over time in antiviral prophylaxis at our institution, patients were divided into the following 3 groups: hybrid (n = 15), traditional (n = 26), and intermediate dose (n = 45). The hybrid group received valganciclovir from admission to day -2 followed by standard-dose valacyclovir. The traditional group received standard-dose valacyclovir starting on day -1. The intermediate-dose group received ganciclovir from admission through day -2, followed by intermediate-dose valacyclovir. The hybrid and intermediate-dose groups were combined into an intensified group for further analysis. We found the cumulative incidence (CI) of CMV reactivation within 100 days post-HCT was higher for patients receiving the traditional strategy compared with the hybrid and intermediate-dose strategy groups (81% versus 53% versus 71%, respectively; P = .08) and was significantly higher when the traditional group was compared against the intensified group (81% versus 67%, respectively; P = .032). Median time to CMV reactivation was also shorter in the traditional group versus the intensified group (31 versus 41 days, respectively). Moreover, the CI of CMV disease by day 100 was significantly worse for patients receiving the traditional prophylaxis strategy among the 3 groups (8% traditional versus 0% hybrid versus 0% intermediate dose; P = .032). Renal toxicity did not differ between the traditional and intensified group. In conclusion, an intensified approach to prevention of CMV reactivation was associated with lower incidence of CMV reactivation and less CMV disease without increased toxicity. Because the most benefit was observed in the intensified group, further studies are needed to assess which antiviral intervention is the most beneficial on lowering the rates of CMV viremia and disease.

Results of a 2-arm, phase 2 clinical trial using post-transplantation cyclophosphamide for the prevention of graft-versus-host disease in haploidentical donor and mismatched unrelated donor hematopoietic stem cell transplantation.

BACKGROUND: High-dose, post-transplantation cyclophosphamide (PTCy) to prevent graft-versus-host disease (GVHD) has improved outcomes in haploidentical (HAPLO) stem cell transplantation (SCT). However, it remains unclear whether this strategy is effective in SCT from 1-antigen human leukocyte antigen (HLA)-mismatched unrelated donors (9/10 MUD) and how the outcomes of these patients compare with those of haploidentical transplantation recipients. METHODS: A parallel, 2-arm, nonrandomized phase 2 clinical trial was conducted of melphalan-based reduced-intensity conditioning with PTCy, tacrolimus, and mycophenolate mofetil to prevent GVHD in patients with high-risk hematologic malignancies who underwent HAPLO (n = 60) or 9/10 MUD (n = 46) SCT. RESULTS: The 1-year overall and progression-free survival rates were 70% and 60%, respectively, in the HAPLO arm and 60% and 47%, respectively, in the 9/10 MUD arm. The day +100 cumulative incidence of grade II to IV acute GVHD and grade III to IV acute GVHD was 28% and 3%, respectively, in the HAPLO arm and 33% and 13%, respectively, in the 9/10 MUD arm. The 2-year cumulative incidence of chronic GVHD was 24% in the HAPLO arm and 19% in the 9/10 MUD arm. The 1-year cumulative incidence of nonrelapse mortality was 21% in the HAPLO arm and 31% in the 9/10 MUD arm, and the 1-year relapse rate was 19% in the HAPLO arm and 25% in the 9/10 MUD arm. CONCLUSIONS: Although this was a nonrandomized study and could not serve as a direct comparison between the 2 groups, the authors conclude that PTCy-based GVHD prophylaxis is effective for both HAPLO and 9/10 MUD SCTs. Prospective randomized trials will be required to compare the efficacies of alternative donor options for patients lacking HLA-matched donors. Cancer 2016;122:3316-3326. © 2016 American Cancer Society.

Therapeutic drug monitoring for either oral or intravenous busulfan when combined with pre- and post-transplantation cyclophosphamide.

Busulfan (Bu)/cyclophosphamide (Cy) is a standard conditioning platform for allogeneic transplantation. We developed a strategy separating the Cy into two pre/post-transplantation doses (PTCy), providing myeloablative conditioning and single-agent graft-versus-host disease (GVHD) prophylaxis. We investigated the impact of Bu route on treatment-related toxicity for 131 consecutive adult patients. Busulfan was administered in four daily divided doses either orally (n = 72) or intravenously (n = 59) with pharmacokinetics on the first-dose and as necessary on subsequent doses to achieve a target area-under-the-concentration-curve (AUC) of 800-1400 µmol*min/L per dose. BuCy/PTCy with pharmacokinetics is well-tolerated with low treatment-related toxicity. Hepatic veno-occlusive disease incidence was 6% with two fatal events. Bu administration route in the context of BuCy/PTCy did not statistically impact hepatotoxicity, GVHD, relapse, disease-free survival, or overall survival. The BuCy/PTCy platform has a low incidence of treatment-related toxicity, including hepatotoxicity, in hematologic malignancies when using pharmacokinetics for a target AUC of 800-1400 µmol*min/L, irrespective of Bu administration route.

An overview of conditioning regimens for haploidentical stem cell transplantation with post-transplantation cyclophosphamide.

Haploidentical related donors are an attractive alternative source of stem cells for allogeneic stem cell transplantation due to widespread availability and ease of stem cell procurement. Historically, haploidentical stem cell transplantation (HaploSCT) with extensive T-cell depletion has been associated with high rates of infectious complications and nonrelapse mortality (NRM). Post-transplantation cyclophosphamide (PTCy) has been shown to induce immune tolerance, effectively control graft-versus-host-disease (GVHD), and is associated with lower NRM, making it a preferred option for patients undergoing HaploSCT. Over the last decade, several groups investigated PTCy for GVHD prevention in HaploSCT; it is now successfully utilized with both myeloablative and nonmyeloablative conditioning regimens with survival comparable to HLA-matched transplantation. Future directions will focus on optimizing conditioning regimens by diagnosis, improving donor selection, and enhancing graft-versus-leukemia effect.

Administration of voriconazole in patients with renal dysfunction.

BACKGROUND: The intravenous use of voriconazole requires coadministration with sulphobutylether-ß-cyclodextrin, which may accumulate in patients with impaired renal function. METHODS: All adult patients treated with the same formulation of voriconazole for a minimum of 3 consecutive days were included. Renal function was assessed based on the creatinine level and the calculated creatinine clearance (CrCl). Change in renal function was calculated on days 3, 7, and end of treatment (EOT) and was defined based on the RIFLE criteria. RESULTS: Among 166 patients in whom baseline renal function was assessed, 42 (25.3%) had a CrCl <50 mL/min and received intravenous voriconazole, 77 (46.4%) had a CrCl ≥50 mL/min and received intravenous voriconazole, and 47 (28.3%) had a CrCl <50 mL/min and were treated with oral voriconazole. Renal function changed on days 3, 7, and EOT in 19 (11.4%), 14 (8.4%), and 28 (16.9%) patients, respectively. Multivariate analyses identified significant predictors of renal dysfunction: (1) day 3, hematologic malignancy (odds ratio [OR], 5.09, P = .01), fluconazole use within 30 days prior to voriconazole (OR, 6.21; P = .008), coadministration of penicillins (OR, 6.12; P = .03), and immunosuppressants (OR, 7.00; P = .002); (2) day 7, baseline liver impairment (OR, 5.30; P value = .004); (3) EOT, administration of penicillins (OR, 2.39; P = .04). CONCLUSIONS: Voriconazole route of administration and baseline renal function were not predictors of worsening renal dysfunction on days 3, 7, and EOT. Underlying disease, baseline liver impairment, and concomitant administration of other drugs (eg, penicillins, fluoroquinolones, immunosuppressants) were the strongest predictors of renal dysfunction.

A retrospective analysis of the effect of patient-specific factors on voriconazole concentrations in oncology patients.

OBJECTIVE: To identify patient-specific factors significantly associated with voriconazole exposure. DESIGN SETTING, AND PARTICIPANTS: Retrospective, single center at an academic medical center. Consecutive, adult oncology inpatients who received voriconazole by mouth and had at least one voriconazole level over a 14-month period. Voriconazole was ordered for 292 patients during the study period, a level was obtained in 41 patients. Nine patients were excluded; the study population was comprised of 32 patients. METHODS AND RESULTS: Univariate and multivariable regression analyses were utilized to predict the patient-specific factors significantly associated with level. A total of 36 levels meeting inclusion/exclusion criteria were performed in 32 patients. Sixty percent of levels (22/36) were between 1 and 5.5 µg/mL. Data were available to calculate a Child Pugh score for 66% (21/32) of patients. Using multivariable linear regression, three covariates were found to be statistically significant: age, international normalized ratio (INR), and alkaline phosphatase (ALP). Three outliers were notable in the ALP category, when removing the three individuals from the model, only an increasing INR remains significantly associated with increasing voriconazole level (p = 0.0093). No correlation was found with trough level and Child Pugh score. CONCLUSIONS: Sixty percent of voriconazole trough levels were between 1 and 5.5 µg/mL (range 0.1-7.4 µg/mL), only increasing INR was significantly associated with rising voriconazole level. Increasing Child Pugh score was not associated with increasing level. More investigation is warranted into the usefulness of the Child Pugh score for guidance of dose modifications in non-cirrhotic patients with acute hepatic injury.

Clinical consequences of analytical variance and calculation strategy in oral busulfan pharmacokinetics.

BACKGROUND: Busulfan pharmacokinetic (PK) monitoring of the area under the concentration-time curve (AUC) is necessary to minimize adverse events associated with both under- and over-dosing of busulfan during hematopoietic stem cell transplantation (HSCT). Three strategies are frequently used to calculate the AUC including in-house polynomial methods, the trapezoidal method (also called noncompartmental analysis), and the single compartment model with first-order elimination method. We compared these 3 methods, their clinical performance, and the relationship of AUC variance to analytical variance when each of these methods is used. METHODS: Clinical busulfan PK data was reviewed from 159 patients receiving the first dose of oral busulfan while undergoing HSCT. These data were used as templates to simulate AUC results and actions with varying amounts of analytical precision. RESULTS: Based on a predefined goal therapeutic target, the method for calculating AUC significantly changed the number of recommended busulfan dose adjustments (p<0.000001). Overall, the number of dose adjustments would be expected to drop by approximately 10% due to calibration optimization of the busulfan concentration measurement method. CONCLUSION: Analytical variance and the AUC calculation method play a considerable role in the clinical management of busulfan dosing during HSCT. With better understanding and optimization of the analytical method, the reliability of clinically actionable information from busulfan PK can increase.