Phase II study of dose-modified busulfan by real-time targeting in allogeneic hematopoietic stem cell transplantation for myeloid malignancy

The effects of a combination oral spray (Mucosamin®) for the prevention of oral mucositis in pediatric patients undergoing hematopoietic stem cell transplantation: a double blind randomized clinical trial

PURPOSE

Oral mucositis (OM) is a frequent complication of conditioning regimens for hematopoietic stem cell transplantation (HSCT). Damage to the nuclear and non-nuclear materials of the mucosal cells by the production of Reactive Oxygen Species (ROS) and proinflammatory cytokines could result to development and progression of OM. Previous studies have shown the effectiveness of !!!Mucosamin® oral spray in the management of pain and acceleration of OM healing. The aims of the current study were to evaluate prophylactic effects of Mucosamin® oral spray in reducing the incidence and severity of OM in pediatric patients undergoing allogeneic HSCT.

METHOD

The current study was designed as a double-blind, placebo-controlled randomized clinical trial. Sixty patients were enrolled in the study and received placebo or Mucosamin® spray. Patients in both groups used sprays 4 times daily. Product application was begun at the time of initiation of conditioning regimen and was continued for 14 days.

RESULTS

Mucosamin® significantly reduced incidence and severity of OM compared to the placebo (P values: 0.027 and 0.035, respectively). This product could also decrease OM duration and delay OM onset (P values: 0.007 and 0.006, respectively).

CONCLUSION

Mucosamin® could effectively reduce incidence, severity, and duration of OM and delay OM onset in pediatric patients undergoing allogeneic HSCT.

TRIAL REGISTRATION

The study protocol was registered in the Iranian Registry of Clinical Trials under the registry number IRCT20190917044805N1.

An analysis of oral microbial flora by T-RFLP in patients undergoing hematopoietic stem cell transplantation

Even though the hematopoietic stem cell transplantation (HSCT) procedure has been improved, oral mucositis (OM) is still a severe complication of the conditioning regimen. We investigated the association between OM severity and the alteration of oral bacterial flora using 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) analysis in 19 consecutive patients undergoing HSCT. Oral samples were collected at pre-transplantation, at the peak of mucositis and post-engraftment. T-RFLP profiles for each timepoint were constructed into an X-Y matrix, and the distances between timepoints were calculated. Patients with severe and moderate OM had larger changes in their oral bacterial flora from before HSCT to peak of mucositis than controls (p = 0.031 and 0.016, respectively). Moreover, severe mucositis was significantly associated with an extended period of fever until engraftment, high maximum C-reactive protein levels, and prolonged periods of opioid treatment and intravenous hyper-alimentation. These findings suggest that mucositis severity is associated with the magnitude of change in the oral bacterial flora. This novel finding may help advance strategies for the prevention or treatment of OM after HSCT.

Analysis of glutathione S-transferase and cytochrome P450 gene polymorphism in recipients of dose-adjusted busulfan-cyclophosphamide conditioning

Sporadic incidence of veno-occlusive disease (VOD) continues to occur, despite achievement of recommended busulfan (BU) concentrations after real-time BU dose adjustment. To explore the potential influence of glutathione S-transferase (GST) and cytochrome P450 (CYP) genotypes on plasma BU concentration, subsequent VOD, and transplant outcome, we assessed the polymorphisms of multiple GST and CYP genes. Fifty-five patients were included (median age 38 years; range 21-67). Of these, 49 received dose-adjusted BU/CY therapy. Twenty-six patients received transplants from human leukocyte antigen-identical siblings, 26 from unrelated donors. The GSTA1*A/*A genotype was significantly associated with lower BU first-dose area under curve (AUC1st). We found that patients with higher AUC1st showed a significantly higher serum total bilirubin during the first month after transplantation, but this was not necessarily associated with subsequent development of VOD. We further analyzed a possible association of GST and CYP polymorphisms and VOD development, and found none of the polymorphisms investigated was associated with VOD incidence. Regarding transplant outcomes, GSTM1-positive patients showed lower relapse rates and better overall survival in multivariate analyses. These results suggest that a GSTM1-positive genotype in patients receiving BU/CY conditioning protects against relapse of hematological malignancies after allogeneic hematopoietic stem cell transplantation.

Pharmacokinetics of intravenous mycophenolate mofetil in allogeneic hematopoietic stem cell-transplanted Japanese patients

PURPOSE

Mycophenolate mofetil (MMF) is increasingly used among Japanese patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT). Because pharmacokinetic data for MMF in the Asian population are limited, we conducted this investigation.

METHODS

Intravenous MMF (1000 mg/dose) was administered to 10 patients along with cyclosporine or tacrolimus for 10 days after allo-SCT; it was administered every 8 h in peripheral blood stem cell- and bone marrow-transplanted patients, and every 12 h in cord blood-transplanted patients. MMF was administered orally at the same dose from day 11. Plasma concentrations of mycophenolic acid (MPA) were measured by high-performance liquid chromatography.

RESULTS

The MPA AUC_0 - tau was 31.9 ± 3.4, 26.2 ± 2.4, and 21.0 ± 2.2 µg*h/mL, the mean C_trough was 0.25, 0.35, and 0.37 µg/mL, and the C_max was 10.8, 9.2, and 5.5 µg/mL on days 2, 9, and 16, respectively. The AUC_0 - tau and C_max were significantly higher after intravenous MMF dosing than after oral MMF dosing. All patients exhibited successful neutrophil engraftments in a median time of 18 days. Grade II acute graft-versus-host disease (GvHD) of the skin was observed in two patients, and one patient developed limited chronic GvHD. Individual cases of transient and curable grade III oral mucositis and diarrhea were observed; however, MMF was not discontinued. No other severe complications or infections were observed.

CONCLUSIONS

Intravenously administered MMF was safe and possibly effective in achieving higher MPA plasma concentrations for GvHD prophylaxis after allo-SCT in Japanese patients.

The Incidence and Severity of Oral Mucositis among Allogeneic Hematopoietic Stem Cell Transplantation Patients: A Systematic Review

Oral mucositis (OM) is a debilitating early adverse effect of allogeneic hematopoietic stem cell transplantation (HSCT). The intensity of the conditioning regimen correlates with the incidence and severity of OM, but no studies have analyzed this relationship among various conditioning regimens. We performed a systematic review on the incidence and outcomes of OM in allogeneic HSCT patients and analyzed this association. A comprehensive search of several databases (Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Cochrane CRCT, Cochrane DSR, Scopus) from 1990 to 2014 for studies of OM in allogeneic HSCT patients was conducted. Professional societies' meeting abstracts were also searched. Grade of OM was analyzed based on the World Health Organization (WHO) or National Cancer Institutes (NCI) Common Terminology Criteria for Adverse Events scales. Severe mucositis was defined as either grades 2 to 4 or grades 3 and 4, depending on the studies' definition of severity. Cohorts were analyzed based on regimen intensity; ie, reduced-intensity conditioning (RIC) (including nonmyeloablative) and myeloablative (MA). Random effect (RE) and standard logistic models weighted by the number of patients in each cohort were used for comparisons. A total of 624 studies were generated from the search. Of the 395 patients in 8 eligible MA regimen studies, 73.2% experienced any OM, whereas in 245 patients in the 6 eligible RIC regimen studies, 86.5% experienced any OM (chi-square P < .0001; RE, P = .05). Severe (grades 2 to 4) OM occurred among 79.7% of the WHO/NCI-graded MA patients and 71.5% of RIC patients (chi-square, P = .0421; RE, P < .01). In comparing graft-versus-host disease (GVHD) prophylaxis, only 55.4% of patients receiving nonmethotrexate regimens experienced OM; this was lower (chi-square, P < .0001; RE, P = .06) than that found among patients who received methotrexate (83.4%), either standard or reduced dose. Besides NCI and WHO grading scales, other scales included in the studies were Oral Mucositis Index, the Southwest Oncology Group Criteria, and Eastern Cooperative Oncology Group scale. To our knowledge, this is the first analysis on OM in allogeneic HSCT patients with respect to conditioning regimens, and we observed that RIC regimens led to a high incidence of OM similar to that of MA regimens. Clinical trials on treatment of OM are lacking, emphasizing the essential need for prospective studies in this arena. A significant variance in the criteria for grading OM underscores the importance of establishing a standard grading system for OM measurement in future allogeneic HSCT clinical trials.

Busulfan dosing algorithm and sampling strategy in stem cell transplantation patients

AIM

The aim of this investigation was to develop a model-based dosing algorithm for busulfan and identify an optimal sampling scheme for use in routine clinical practice.

METHODS

Clinical data from an ongoing study (n = 29) in stem cell transplantation patients were used for the purposes our analysis. A one compartment model was selected as basis for sampling optimization and subsequent evaluation of a suitable dosing algorithm. Internal and external model validation procedures were performed prior to the optimization steps using ED-optimality criteria. Using systemic exposure as parameter of interest, dosing algorithms were considered for individual patients with the scope of minimizing the deviation from target range as determined by AUC(0,6 h).

RESULTS

Busulfan exposure after oral administration was best predicted after the inclusion of adjusted ideal body weight and alanine transferase as covariates on clearance. Population parameter estimates were 3.98 h(-1), 48.8 l and 12.3 l h(-1) for the absorption rate constant, volume of distribution and oral clearance, respectively. Inter-occasion variability was used to describe the differences between test dose and treatment. Based on simulation scenarios, a dosing algorithm was identified, which ensures target exposure values are attained after a test dose. Moreover, our findings show that a sparse sampling scheme with five samples per patient is sufficient to characterize the pharmacokinetics of busulfan in individual patients.

CONCLUSION

The use of the proposed dosing algorithm in conjunction with a sparse sampling scheme may contribute to considerable improvement in the safety and efficacy profile of patients undergoing treatment for stem cell transplantation.

Phase II study of dose-modified busulfan by real-time targeting in allogeneic hematopoietic stem cell transplantation for myeloid malignancy

We aimed to evaluate the efficacy and safety of allogeneic hematopoietic stem cell transplantation with targeted oral busulfan (BU) and cyclophosphamide (CY) in a phase II study. Busulfan (1.0 mg/kg) was given initially in six doses. Based on the estimated concentration at steady state after the first dose of BU, subsequent (7th-16th) doses were adjusted to obtain a targeted overall concentration at steady state of 700-900 ng/mL. The primary endpoint was 1-year overall survival (OS). Fifty patients were registered and 46 (median age, 53 years; range, 18-62 years) received planned transplant, including 24 with AML, 16 with myelodysplastic syndrome, and six with CML. Fourteen patients were categorized as standard risk. Nineteen patients received transplant from human leukocyte antigen-identical siblings, 27 from unrelated donors. The BU dose required reduction in 32 patients and escalation in six patients. One-year OS was 65% (95% confidence interval, 50-77%). Cumulative incidence of hepatic sinusoidal obstruction syndrome was 11%. One-year transplant-related mortality was 18%. Both OS and transplant-related mortality were favorable in this study, including patients of older age and with high risk diseases. Individual dose adjustment based on BU pharmacokinetics was feasible and effective in the current phase II study. This trial is registered in the University Hospital Medical Information Network Clinical Trial Registry System (UMIN-CTR, ID:C000000156).