Modeling unrelated blood stem cell donor recruitment using simulated registrant cohorts: Assessment of human leukocyte antigen matching across ethnicity groups.

BACKGROUND: Human leukocyte antigen (HLA)-matched unrelated donors are not available for some patients considered for allogeneic hematopoietic cell transplantation, particularly among certain ethnic groups. Simulated recruitment modeling can inform efforts to find new matches for more patients. METHODS: Simulated recruits were generated by assigning a pair of donor HLA haplotypes from historical data files and matched against HLA data of patient searches in the Canadian Blood Services Stem Cell Registry. Recruitment cohorts reflected the proportion of five specific ethnic groups in the 2016 Canadian census data. RESULTS: Novel 8/8 HLA matches between simulated recruits and patients increased linearly with larger recruitment cohorts. The proportion of novel 8/8 HLA matches from Caucasian, Hispanic, and Native American/First Nations recruits was equal to or greater than their relative proportion in the recruited cohort (match to: recruit ratio (MRR) ≥ 1). In contrast, African American and Asian & Pacific Islander recruits represented a smaller proportion of novel matches relative to their percentage of the recruited cohort (MRR <1). The proportion of novel 7/8 HLA-matches from each ethnic group was approximately the same as their proportion in the recruited cohort (MRR ~ 1) and high rates of 7/8 HLA-matching already exist within the Canadian Blood Services registry for all ethnic groups. CONCLUSION: Continued large recruitment cohorts are needed to add new 8/8 HLA matches to registry inventories. Likelihoods of novel HLA matches varied across ethnic groups, reflecting varied HLA haplotype frequencies across groups. Simulated cohort modeling can inform recruitment strategies that will generate new donor options for patients.

Cost-Effectiveness of Brexucabtagene Autoleucel versus Best Supportive Care for the Treatment of Relapsed/Refractory Mantle Cell Lymphoma following Treatment with a Bruton's Tyrosine Kinase Inhibitor in Canada.

For patients with Mantle Cell Lymphoma (MCL), there is no recognized standard of care for relapsed/refractory (R/R) disease after treatment with a Bruton's tyrosine kinase inhibitor (BTKi). Brexucabtagene autoleucel (brexu-cel) represents a promising new treatment modality in MCL. We explored whether brexu-cel was cost-effective for the treatment of R/R MCL. We developed a partitioned survival mixture cure approach to model the costs and outcomes over a lifetime horizon. The clinical data were derived from the ZUMA-2 clinical trial. The costs were estimated from the publicly available Canadian databases, published oncology literature, and pan-Canadian Oncology Drug Review economic guidance reports. The health state utilities were sourced from the ibrutinib submission to the National Institute for Health and Care Excellence for R/R MCL and supplemented with values from the published oncology literature. In the base case over a lifetime horizon, brexu-cel generated an incremental 9.56 life-years and an additional 7.03 quality-adjusted life-years compared to BSC, while associated with CAD 621,933 in additional costs. The resultant incremental cost-utility ratio was CAD 88,503 per QALY gained compared with BSC. Based on this analysis, we found brexu-cel to be a cost-effective use of healthcare resources relative to BSC for treatment of adult patients with R/R MCL previously treated with a BTKi in Canada, though additional research is needed to confirm these results using longer follow-up data.

Country-Level Macroeconomic Indicators Predict Early Post-Allogeneic Hematopoietic Cell Transplantation Survival in Acute Lymphoblastic Leukemia: A CIBMTR Analysis.

For patients with acute lymphoblastic leukemia (ALL), allogeneic hematopoietic cell transplantation (alloHCT) offers a potential cure. Life-threatening complications can arise from alloHCT that require the application of sophisticated health care delivery. The impact of country-level economic conditions on post-transplantation outcomes is not known. Our objective was to assess whether these variables were associated with outcomes for patients transplanted for ALL. Using data from the Center for Blood and Marrow Transplant Research, we included 11,261 patients who received a first alloHCT for ALL from 303 centers across 38 countries between the years of 2005 and 2013. Cox regression models were constructed using the following macroeconomic indicators as main effects: Gross national income per capita, health expenditure per capita, and Human Development Index (HDI). The outcome was overall survival at 100 days following transplantation. In each model, transplants performed within lower resourced environments were associated with inferior overall survival. In the model with the HDI as the main effect, transplants performed in the lowest HDI quartile (n = 697) were associated with increased hazard for mortality (hazard ratio, 2.42; 95% confidence interval, 1.64 to 3.57; P < .001) in comparison with transplants performed in the countries with the highest HDI quartile. This translated into an 11% survival difference at 100 days (77% for lowest HDI quartile versus 88% for all other quartiles). Country-level macroeconomic indices were associated with lower survival at 100 days after alloHCT for ALL. The reasons for this disparity require further investigation.

Choosing Wisely BMT: American Society for Blood and Marrow Transplantation and Canadian Blood and Marrow Transplant Group's List of 5 Tests and Treatments to Question in Blood and Marrow Transplantation.

Choosing Wisely encourages dialogue about reducing unnecessary procedures, tests, or treatments in healthcare. The American Society for Blood and Marrow Transplantation (ASBMT) and Canadian Blood and Marrow Transplant Group (CBMTG) established a Choosing Wisely BMT Task Force whose objective was to create a list of top 5 practices in blood and marrow transplantation to be questioned. The Task Force consisted of representatives from ASBMT's Quality Outcomes, Education, and Practice Guidelines committees; ASBMT's Pharmacy Special Interest Group; CBMTG Program Directors; and Center for International Blood and Marrow Transplant Research (CIBMTR). Suggestions for current transplantation practices to question were elicited from the CBMTG Program Directors; members of ASBMT's Quality Outcomes, Practice Guidelines, and Education committees; and chairs of the CIBMTR scientific working committees. We received 119 unique suggestions that were ranked based on their potential impact on harm reduction, cost reduction, necessity of the test or practice, and the strength of available evidence. Through a modified Delphi process, suggestions were narrowed down to 6, which were then subjected to systematic reviews. The final 5 recommendations focus on graft source for patients with aplastic anemia, corticosteroid dose for initial treatment of graft-versus-host-disease, optimal number of umbilical cord blood units for transplantation, graft source in matched unrelated donor transplantation, and use of prophylactic intravenous immunoglobulin in transplant recipients. These Choosing Wisely BMT recommendations are relevant to the current clinical practice of blood and marrow transplantation and focus on tests, treatments, or procedures that may be harmful, wasteful, or for which there is no apparent clinical benefit.

Assessment of Impact of HLA Type on Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy with many highly effective therapies. Chemorefractory disease, often characterized by deletion of chromosome 17p, has historically been associated with very poor outcomes, leading to the application of allogeneic hematopoietic stem cell transplantation (allo-HCT) for medically fit patients. Although the use of allo-HCT has declined since the introduction of novel targeted therapy for the treatment of CLL, there remains significant interest in understanding factors that may influence the efficacy of allo-HCT, the only known curative treatment for CLL. The potential benefit of transplantation is most likely due to the presence of alloreactive donor T cells that mediate the graft-versus-leukemia (GVL) effect. The recognition of potentially tumor-specific antigens in the context of class I and II major histocompatibility complex on malignant B lymphocytes by donor T cells may be influenced by subtle differences in the highly polymorphic HLA locus. Given previous reports of specific HLA alleles impacting the incidence of CLL and the clinical outcomes of allo-HCT for CLL, we sought to study the overall survival and progression-free survival of a large cohort of patients with CLL who underwent allo-HCT from fully HLA-matched related and unrelated donors at Center for International Blood and Marrow Transplant Research transplantation centers. We found no statistically significant association of allo-HCT outcomes in CLL based on previously reported HLA combinations. Additional study is needed to further define the immunologic features that portend a more favorable GVL effect after allo-HCT for CLL.

Economic evaluation of rituximab in addition to standard of care chemotherapy for adult patients with acute lymphoblastic leukemia.

AIMS: Acute lymphoblastic leukemia (ALL) is an aggressive form of leukemia with a poor prognosis in adult patients. The addition of the monoclonal antibody rituximab to standard chemotherapy has been shown to improve survival in adults with ALL. However, it is unknown whether the addition of rituximab is cost-effective. The objective was to determine the economic impact of rituximab in addition to standard of care (SOC) chemotherapy vs SOC alone in newly-diagnosed Philadelphia chromosome-negative, CD20-positive, B-cell precursor ALL. METHODS: A decision analytic model was constructed, based upon the Canadian healthcare system. It included the following health states over a lifetime horizon (max ≈60 years): event-free survival (EFS), relapsed/resistant disease, cure, and death. SOC was either hyper-CVAD or the Dana Farber Cancer Institute (DFCI) ALL consortium. EFS, overall survival, and serious adverse event (SAE) rates were derived from a large randomized controlled trial. Costs of the model included: first-line treatment and administration, disease management, second-line and third-line treatment and administration, palliative care, and SAE-related treatments. Inputs were sourced from provincial and national public data, the literature, and cancer agency input. RESULTS: Quality-adjusted life-years (QALYs) increased by 2.20 QALYs with rituximab in addition to SOC. The resulting mean Incremental Cost-Effectiveness Ratio (ICER) was C$21,828/QALY. At a willingness-to-pay threshold of C$100,000/QALY, the probability of being cost-effective was 98%. Decision outcomes were robust to the probabilistic and deterministic sensitivity analyses, including the SOC backbone as either hyper-CVAD or DFCI. LIMITATIONS: The results of this analysis are limited by generalizability of the chemotherapy backbone to Canadian practice. CONCLUSIONS: For adults with ALL, rituximab in addition to SOC was found to be a cost-effective intervention, compared to SOC alone. The addition of rituximab is associated with increased life years and increased QALYs at a reasonable incremental cost.

Comparing Outcomes with Bone Marrow or Peripheral Blood Stem Cells as Graft Source for Matched Sibling Transplants in Severe Aplastic Anemia across Different Economic Regions.

Bone marrow (BM) is the preferred graft source for hematopoietic stem cell transplantation (HSCT) in severe aplastic anemia (SAA) compared with mobilized peripheral blood stem cells (PBSCs). We hypothesized that this recommendation may not apply to those regions where patients present later in their disease course, with heavier transfusion load and with higher graft failure rates. Patients with SAA who received HSCT from an HLA-matched sibling donor from 1995 to 2009 and reported to the Center for International Blood and Marrow Transplant Research or the Japan Society for Hematopoietic Cell Transplantation were analyzed. The study population was categorized by gross national income per capita and region/countries into 4 groups. Groups analyzed were high-income countries (HIC), which were further divided into United States-Canada (n = 486) and other HIC (n = 1264); upper middle income (UMIC) (n = 482); and combined lower-middle, low-income countries (LM-LIC) (n = 142). In multivariate analysis, overall survival (OS) was highest with BM as graft source in HIC compared with PBSCs in all countries or BM in UMIC or LM-LIC (P < .001). There was no significant difference in OS between BM and PBSCs in UMIC (P = .32) or LM-LIC (P = .23). In LM-LIC the 28-day neutrophil engraftment was higher with PBSCs compared with BM (97% versus 77%, P = .002). Chronic graft-versus-host disease was significantly higher with PBSCs in all groups. Whereas BM should definitely be the preferred graft source for HLA-matched sibling HSCT in SAA, PBSCs may be an acceptable alternative in countries with limited resources when treating patients at high risk of graft failure and infective complications.