Autologous transplant vs. CAR-T therapy in patients with DLBCL treated while in complete remission.

In patients with relapsed DLBCL in complete remission (CR), autologous hematopoietic cell transplantation (auto-HCT) and CAR-T therapy are both effective, but it is unknown which modality provides superior outcomes. We compared the efficacy of auto-HCT vs. CAR-T in patients with DLBCL in a CR. A retrospective observational study comparing auto-HCT (2015-2021) vs. CAR-T (2018-2021) using the Center for International Blood & Marrow Transplant Research registry. Median follow-up was 49.7 months for the auto-HCT and 24.7 months for the CAR-T cohort. Patients ages 18 and 75 with a diagnosis of DLBCL were included if they received auto-HCT (n = 281) or commercial CAR-T (n = 79) while in a CR. Patients undergoing auto-HCT with only one prior therapy line and CAR-T patients with a previous history of auto-HCT treatment were excluded. Endpoints included Progression-free survival (PFS), relapse rate, non-relapse mortality (NRM) and overall survival (OS). In univariate analysis, treatment with auto-HCT was associated with a higher rate of 2-year PFS (66.2% vs. 47.8%; p < 0.001), a lower 2-year cumulative incidence of relapse (27.8% vs. 48% ; p < 0.001), and a superior 2-year OS (78.9% vs. 65.6%; p = 0.037). In patients with early (within 12 months) treatment failure, auto-HCT was associated with a superior 2-year PFS (70.9% vs. 48.3% ; p < 0.001), lower 2-year cumulative incidence of relapse (22.8% vs. 45.9% ; p < 0.001) and trend for higher 2-year OS (82.4% vs. 66.1% ; p = 0.076). In the multivariable analysis, treatment with auto-HCT was associated with a superior PFS (hazard ratio 1.83; p = 0.0011) and lower incidence of relapse (hazard ratio 2.18; p < 0.0001) compared to CAR-T. In patients with relapsed LBCL who achieve a CR, treatment with auto-HCT is associated with improved clinical outcomes compared to CAR-T. These data support the consideration of auto-HCT in select patients with LBCL achieving a CR in the relapsed setting.

Incidence and outcomes of cytomegalovirus reactivation after chimeric antigen receptor T-cell therapy.

ABSTRACT: Cytomegalovirus (CMV) reactivation is a major complication among seropositive allogeneic hematopoietic cell transplantation recipients; however, data on CMV reactivation after chimeric antigen receptor (CAR) T-cell therapy are limited. We report the incidence and outcomes of 95 adult CMV-seropositive patients who received CAR T-cell therapy between February 2018 and February 2023. CMV outcomes were CMV reactivation (any viremia) and clinically significant CMV infection (cs-CMV). Thirty-one patients (33%) had evidence of CMV reactivation (any viremia), and 10 patients (11%) had cs-CMV. The median time from CAR T-cell infusion to CMV reactivation was 19 days (interquartile range [IQR], 9-31). The cumulative incidence of CMV (any viremia) was significantly higher among patients with grade 3 to 4 cytokine release syndrome (67 vs 28%; P = .01), and those who received corticosteroids (39 vs 21%; P = .03), anakinra (56 vs 28%; P = .02), or ≥2 immunosuppressants (41 vs 21%; P = .02). Receipt of corticosteroids (18 vs 0%; P = .004), tocilizumab (14 vs 0%; P = .04), anakinra (33 vs 7%; P = .008), and ≥2 immunosuppressants (20 vs 0%; P = .001) were all associated with cs-CMV. Receiving ≥2 immunosuppressants was associated with a twofold increase in CMV reactivation in multivariate analyses (adjusted odds ratio [aOR], 2.27; 95% confidence interval, 1.1-4.8; P = .03). Overall, the 1-year mortality was significantly higher in those with CMV reactivation (57% vs 23%; P = .001). Immunosuppression, particularly with corticosteroids, for the management of CAR T-cell toxicities, is a major risk factor for CMV reactivation.

Donor Types and Outcomes of Transplantation in Myelofibrosis: A CIBMTR Study.

We aim to evaluate impact of donor types on outcomes of hematopoietic cell transplantation (HCT) in myelofibrosis, using CIBMTR registry data for HCTs done between 2013 and 2019. In all 1597 undergoing HCT for myelofibrosis, the use of haploidentical donors increased from 3% in 2013 to 19% in 2019. In study eligible, 1032 patients who received peripheral blood grafts for chronic phase myelofibrosis, 38% recipients of haploidentical-HCT were of non-White/Caucasian ethnicity. Matched sibling donor (MSD)-HCTs were independently associated with superior overall survival (OS) in the first 3 months [reference MSD, haploidentical HR 5.80 (95% CI 2.52-13.35), matched unrelated HR 4.50 (95% CI 2.24-9.03), and mismatched unrelated HR 5.13 (95% CI 1.44-18.31), P<0.001]. This difference in OS aligns with lower graft failure with MSD [haploidentical HR 6.11 (95%CI 2.98-12.54), matched unrelated HR 2.33 (95%CI 1.20-4.51), mismatched unrelated HR 1.82 (95%CI 0.58-5.72). There was no significant difference in OS among haploidentical, matched unrelated, and mismatched unrelated donor HCTs in the first 3 months. Donor type was not associated with differences in OS beyond 3 months post-HCT, relapse, disease-free survival or OS among patients who underwent HCT within 24 months of diagnosis. Patients who experienced graft failure had more advanced disease and commonly used nonmyeloablative conditioning. While MSDs remain a superior donor option due to improved engraftment, there is no significant difference in HCT outcomes from haploidentical and matched unrelated donors. These results establish haploidentical-HCT with posttransplantation cyclophosphamide as a viable option in myelofibrosis, especially for ethnic minorities underrepresented in the donor registries.

Racial, Ethnic and Socioeconomic Diversity and Outcomes of Patients with Graft-versus-Host Disease: A CIBMTR Analysis.

Socioeconomic status (SES) and race/ethnicity have been associated with outcomes of allogeneic hematopoietic cell transplantation (allo-HCT). Certain aspects of GVHD management such as the need for long term care, prolonged immunosuppressive treatment, and need for close follow up for complications may exacerbate disparities. Adults (≥ 18 years) reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) who underwent a first alloHCT for acute leukemia, myelodysplastic syndrome, or myeloproliferative neoplasm between 2008 - 2018 were included. Endpoints for those developing GVHD included overall survival (OS), transplant related mortality (TRM), and disease relapse. Models were adjusted for patient and transplant related variables. A two-sided p-value < 0.01 was considered significant. Among the 14,825 allo-HCT recipients, 6,259 (42.2%) and 6,675 (45.0%) patients developed aGVHD and cGVHD, respectively. In patients with aGVHD, non-Hispanic Blacks had increased TRM (HR 1.50, 95% CI 1.24-1.83, p=0.0001) and overall mortality (HR 1.31, 1.14-1.50, p=0.0002) compared with non-Hispanic Whites, an association that disappeared when severity of aGVHD was included in the model. Lower SES was associated with increased risk of disease relapse (p=0.0016) but not OS or TRM. In patients who developed cGVHD, race and ethnicity were not associated with OS, TRM and disease relapse. However, the highest quartile of annual household income (≥ $80,000) had improved OS (HR 0.77, 0.69-0.85, p<0.0001) and reduced TRM (HR 0.86, 0.67-0.87, p<0.0001) compared with lowest quartile, adjusting for race and ethnicity. Race/ethnicity and SES are associated with outcomes after GVHD. Optimizing health care resources available to low SES patients and strategies to minimize the risk of severe GVHD in non-Hispanic Blacks may improve long-term outcomes.

Trends in volumes and survival after hematopoietic cell transplantation in racial/ethnic minorities.

ABSTRACT: There has been an increase in volume as well as an improvement in overall survival (OS) after hematopoietic cell transplantation (HCT) for hematologic disorders. It is unknown if these changes have affected racial/ethnic minorities equally. In this observational study from the Center for International Blood and Marrow Transplant Research of 79 904 autologous (auto) and 65 662 allogeneic (allo) HCTs, we examined the volume and rates of change of autoHCT and alloHCT over time and trends in OS in 4 racial/ethnic groups: non-Hispanic Whites (NHWs), non-Hispanic African Americans (NHAAs), and Hispanics across 5 2-year cohorts from 2009 to 2018. Rates of change were compared using Poisson model. Adjusted and unadjusted Cox proportional hazards models examined trends in mortality in the 4 racial/ethnic groups over 5 study time periods. The rates of increase in volume were significantly higher for Hispanics and NHAAs vs NHW for both autoHCT and alloHCT. Adjusted overall mortality after autoHCT was comparable across all racial/ethnic groups. NHAA adults (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.04-1.22; P = .004) and pediatric patients (HR 1.62; 95% CI 1.3-2.03; P < .001) had a higher risk of mortality after alloHCT than NHWs. Improvement in OS over time was seen in all 4 groups after both autoHCT and alloHCT. Our study shows the rate of change for the use of autoHCT and alloHCT is higher in NHAAs and Hispanics than in NHWs. Survival after autoHCT and alloHCT improved over time; however, NHAAs have worse OS after alloHCT, which has persisted. Continued efforts are needed to mitigate disparities for patients requiring alloHCT.

A US Multicenter Collaborative Study on Outcomes of Hematopoietic Cell Transplantation in Hepatosplenic T-Cell Lymphoma.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare and aggressive type of peripheral T-cell lymphoma with median overall survival (OS) of approximately 1 year. Data on the effectiveness of hematopoietic cell transplantation (HCT) is limited, as is the choice between autologous HCT (auto-HCT) and allogeneic HCT (allo-HCT) in the treatment of this disease. To evaluate the outcome of patients with HSTCL who underwent either auto-HCT or allo-HCT, we performed a multi-institutional retrospective cohort study to assess outcomes of HCT in HSTCL patients. Fifty-three patients with HSTCL were included in the study. Thirty-six patients received an allo-HCT and 17 received an auto-HCT. Thirty-five (66%) were males. Median age at diagnosis was 38 (range 2 to 64) years. Median follow-up for survivors was 75 months (range 8 to 204). The median number of prior lines of therapy was 1 (range 1 to 4). Median OS and progression-free survival (PFS) for the entire cohort were 78.5 months (95% CI: 25 to 79) and 54 months (95% CI: 18 to 75), respectively. There were no significant differences in OS (HR: 0.63, 95% CI: 0.28 to 1.45, P = .245) or PFS (HR: 0.7, 95% CI: 0.32 to 1.57, P = .365) between the allo-HCT and auto-HCT groups, respectively. In the allo-HCT group, the 3-year cumulative incidence of relapse was 35% (95% CI: 21 to 57), while 3-year cumulative incidence of NRM was 16% (95% CI: 7 to 35). In the auto-HCT group, the 3-year cumulative incidence of relapse and NRM were 43% (95% CI: 23 to 78) and 14% (95% CI: 4 to 52), respectively. Both Auto-HCT and Allo-HCT are effective consolidative strategies in patients with HSTCL, and patients should be promptly referred for HCT evaluation.

Tabelecleucel for allogeneic haematopoietic stem-cell or solid organ transplant recipients with Epstein-Barr virus-positive post-transplant lymphoproliferative disease after failure of rituximab or rituximab and chemotherapy (ALLELE): a phase 3, multicentre, open-label trial.

BACKGROUND: Survival in Epstein-Barr virus (EBV)-positive post-transplant lymphoproliferative disease following haematopoietic stem-cell transplant (HSCT) or solid organ transplant (SOT) is poor after failure of initial therapy, indicating an urgent need for therapies for this ultra-rare disease. With recent EU marketing authorisation, tabelecleucel is the first off-the-shelf, allogeneic, EBV-specific T-cell immunotherapy to receive approval for treatment of relapsed or refractory EBV-positive post-transplant lymphoproliferative disease. We aimed to determine the clinical benefit of tabelecleucel in patients with relapsed or refractory EBV-positive post-transplant lymphoproliferative disease following HSCT or SOT. METHODS: In this global, multicentre, open-label, phase 3 trial, eligible patients (of any age) had biopsy-proven EBV-positive post-transplant lymphoproliferative disease, disease that was relapsed or refractory to rituximab after HSCT and rituximab with or without chemotherapy after SOT, and partially HLA-matched and appropriately HLA-restricted tabelecleucel available. Patients received tabelecleucel administered intravenously at 2 × 106 cells per kg on days 1, 8, and 15 in 35-day cycles and are assessed for up to 5 years for survival post-treatment initiation. The primary endpoint was objective response rate. All patients who received at least one dose of tabelecleucel were included in safety and efficacy analyses. This trial is registered with ClinicalTrials.gov, NCT03394365, and is ongoing. FINDINGS: From June 27, 2018, to Nov 5, 2021, 63 patients were enrolled, of whom 43 (24 [56%] male and 19 [44%] female) were included, 14 had prior HSCT, 29 had SOT. Seven (50%, 95% CI 23-77) of 14 participants in the HSCT group and 15 (52%, 33-71) of 29 participants in the SOT group had an objective response, with a median follow-up of 14·1 months (IQR 5·7-23·9) and 6·0 months (1·8-18·4), respectively. The most common grade 3 or 4 treatment-emergent adverse events were disease progression (in four [29%] of 14 in HSCT and eight [28%] of 29 in SOT) and decreased neutrophil count (in four [29%] of 14 in HSCT and four [14%] of 29 in SOT). Treatment-emergent serious adverse events were reported in 23 (53%) of 43 patients and fatal treatment-emergent adverse events in five (12%); no fatal treatment-emergent adverse event was treatment-related. There were no reports of tumour flare reaction, cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, transmission of infectious diseases, marrow rejection, or infusion reactions. No events of graft-versus-host disease or SOT rejection were reported as related to tabelecleucel. INTERPRETATION: Tabelecleucel provides clinical benefit in patients with relapsed or refractory EBV-positive post-transplant lymphoproliferative disease, for whom there are no other approved therapies, without evidence of safety concerns seen with other adoptive T-cell therapies. These data represent a potentially transformative and accessible treatment advance for patients with relapsed or refractory disease with few treatment options. FUNDING: Atara Biotherapeutics.

Intensive care risk and long-term outcomes in pediatric allogeneic hematopoietic cell transplant recipients.

ABSTRACT: Allogeneic hematopoietic cell transplantation (HCT) can be complicated by life-threatening organ toxicity and infection necessitating intensive care. Epidemiologic data have been limited by single-center studies, poor database granularity, and a lack of long-term survivors. To identify contemporary trends in intensive care unit (ICU) use and long-term outcomes, we merged data from the Center for International Blood and Marrow Transplant Research and the Virtual Pediatric Systems databases. We identified 6995 pediatric patients with HCT aged ≤21 years who underwent first allogeneic HCT between 2008 and 2014 across 69 centers in the United States or Canada and followed patients until the year 2020. ICU admission was required for 1067 patients (8.3% by day +100, 12.8% by 1 year, and 15.3% by 5 years after HCT), and was linked to demographic background, pretransplant organ toxicity, allograft type and HLA-match, and the development of graft-versus-host disease or malignancy relapse. Survival to ICU discharge was 85.7%, but more than half of ICU survivors required ICU readmission, leading to 52.5% and 42.6% survival at 1- and 5-years post-ICU transfer, respectively. ICU survival was worse among patients with malignant disease, poor pretransplant organ function, and alloreactivity risk factors. Among 1-year HCT survivors, those who required ICU in the first year had 10% lower survival at 5 years and developed new dialysis-dependent renal failure at a greater rate (P<.001). Thus, although ICU management is common and survival to ICU discharge is high, ongoing complications necessitate recurrent ICU admission and lead to a poor 1-year outcome in select patients who are at high risk.

Allogeneic hematopoietic cell transplantation for blastic plasmacytoid dendritic cell neoplasm: a CIBMTR analysis.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy with a poor prognosis and considered incurable with conventional chemotherapy. Small observational studies reported allogeneic hematopoietic cell transplantation (allo-HCT) offers durable remissions in patients with BPDCN. We report an analysis of patients with BPDCN who received an allo-HCT, using data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). We identified 164 patients with BPDCN from 78 centers who underwent allo-HCT between 2007 and 2018. The 5-year overall survival (OS), disease-free survival (DFS), relapse, and nonrelapse mortality (NRM) rates were 51.2% (95% confidence interval [CI], 42.5-59.8), 44.4% (95% CI, 36.2-52.8), 32.2% (95% CI, 24.7-40.3), and 23.3% (95% CI, 16.9-30.4), respectively. Disease relapse was the most common cause of death. On multivariate analyses, age of ≥60 years was predictive for inferior OS (hazard ratio [HR], 2.16; 95% CI, 1.35-3.46; P = .001), and higher NRM (HR, 2.19; 95% CI, 1.13-4.22; P = .02). Remission status at time of allo-HCT (CR2/primary induction failure/relapse vs CR1) was predictive of inferior OS (HR, 1.87; 95% CI, 1.14-3.06; P = .01) and DFS (HR, 1.75; 95% CI, 1.11-2.76; P = .02). Use of myeloablative conditioning with total body irradiation (MAC-TBI) was predictive of improved DFS and reduced relapse risk. Allo-HCT is effective in providing durable remissions and long-term survival in BPDCN. Younger age and allo-HCT in CR1 predicted for improved survival, whereas MAC-TBI predicted for less relapse and improved DFS. Novel strategies incorporating allo-HCT are needed to further improve outcomes.

Critical Illness Risk and Long-Term Outcomes Following Intensive Care in Pediatric Hematopoietic Cell Transplant Recipients.

Background: Allogeneic hematopoietic cell transplantation (HCT) can be complicated by the development of organ toxicity and infection necessitating intensive care. Risk factors for intensive care admission are unclear due to heterogeneity across centers, and long-term outcome data after intensive care are sparse due to a historical paucity of survivors. Methods: The Center for International Blood and Marrow Transplant Research (CIBMTR) was queried to identify patients age ≤21 years who underwent a 1st allogeneic HCT between 2008-2014 in the United States or Canada. Records were cross-referenced with the Virtual Pediatric Systems pediatric ICU database to identify intensive care admissions. CIBMTR follow-up data were collected through the year 2020. Result: We identified 6,995 pediatric HCT patients from 69 HCT centers, of whom 1,067 required post-HCT intensive care. The cumulative incidence of PICU admission was 8.3% at day +100, 12.8% at 1 year, and 15.3% at 5 years post HCT. PICU admission was linked to younger age, lower median zip code income, Black or multiracial background, pre-transplant organ toxicity, pre-transplant CMV seropositivity, use of umbilical cord blood and/or HLA-mismatched allografts, and the development of post-HCT graft-versus-host disease or malignancy relapse. Among PICU patients, survival to ICU discharge was 85.7% but more than half of ICU survivors were readmitted to a PICU during the study interval. Overall survival from the time of 1st PICU admission was 52.5% at 1 year and 42.6% at 5 years. Long-term post-ICU survival was worse among patients with malignant disease (particularly if relapsed), as well as those with poor pre-transplant organ function and alloreactivity risk-factors. In a landmark analysis of all 1-year HCT survivors, those who required intensive care in the first year had 10% lower survival at 5 years (77.1% vs. 87.0%, p<0.001) and developed new dialysis-dependent renal failure at a greater rate (p<0.001). Conclusions: Intensive care management is common in pediatric HCT patients. Survival to ICU discharge is high, but ongoing complications necessitate recurrent ICU admission and lead to a poor 1-year outcome in many patients. Together, these data suggest an ongoing burden of toxicity in pediatric HCT patients that continues to limit long-term survival.

Racial and Socioeconomic Disparities in Long-Term Outcomes in ≥1 Year Allogeneic Hematopoietic Cell Transplantation Survivors: A CIBMTR Analysis.

Racial/ethnic minorities have demonstrated worse survival after allogeneic hematopoietic cell transplantation (HCT) compared to whites. Whether the racial disparity in HCT outcomes persists in long-term survivors and possibly may be even exacerbated in this population, which frequently transitions back from the transplant center to their local healthcare providers, is unknown. In the current study, we compared long-term outcomes among 1-year allogeneic HCT survivors by race/ethnicity and socioeconomic status (SES). The Center for International Blood and Marrow Transplant Research database was used to identify 5473 patients with acute myeloid leukemia, acute lymphocytic leukemia, chronic myeloid leukemia, or myelodysplastic syndromes who underwent their first allogeneic HCT between 2007 and 2017 and were alive and in remission for at least 1 year after transplantation. The study was restricted to patients who underwent HCT in the United States. SES was defined using patient neighborhood poverty level estimated from the recipient's ZIP code of residence; a ZIP code with ≥20% of persons below the federal poverty level was considered a high poverty area. The primary outcome was to evaluate the associations of race/ethnicity and neighborhood poverty level with overall survival (OS), relapse, and nonrelapse mortality (NRM). Cox regression models were used to determine associations of ethnicity/race and SES with OS, relapse, and NRM. Standardized mortality ratios were calculated to compare mortality rates of the study patients and their general population peers matched on race/ethnicity, age, and sex. The study cohort was predominately non-Hispanic white (n = 4385) and also included non-Hispanic black (n = 338), Hispanic (n = 516), and Asian (n = 234) patients. Overall, 729 patients (13%) resided in high-poverty areas. Significantly larger proportions of non-Hispanic black (37%) and Hispanic (26%) patients lived in high-poverty areas compared to non-Hispanic whites (10%) and Asians (10%) (P < .01). Multivariable analysis revealed no significant associations between OS, PFS, relapse, or NRM and race/ethnicity or poverty level when adjusted for patient-, disease- and transplantation-related covariates. Our retrospective cohort registry study shows that among adult allogeneic HCT recipients who survived at least 1 year in remission, there were no associations between race/ethnicity, neighborhood poverty level, and long-term outcomes.

A simple prognostic system in patients with myelofibrosis undergoing allogeneic stem cell transplantation: a CIBMTR/EBMT analysis.

To develop a prognostic model for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) for myelofibrosis (MF), we examined the data of 623 patients undergoing allo-HCT between 2000 and 2016 in the United States (the Center for International Blood and Marrow Transplant Research [CIBMTR] cohort). A Cox multivariable model was used to identify factors prognostic of mortality. A weighted score using these factors was assigned to patients who received transplantation in Europe (the European Bone Marrow Transplant [EBMT] cohort; n = 623). Patient age >50 years (hazard ratio [HR], 1.39; 95% confidence interval [CI], 0.98-1.96), and HLA-matched unrelated donor (HR, 1.29; 95% CI, 0.98-1.7) were associated with an increased hazard of death and were assigned 1 point. Hemoglobin levels <100 g/L at time of transplantation (HR, 1.63; 95% CI, 1.2-2.19) and a mismatched unrelated donor (HR, 1.78; 95% CI, 1.25-2.52) were assigned 2 points. The 3-year overall survival (OS) in patients with a low (1-2 points), intermediate (3-4 points), and high score (5 points) were 69% (95% CI, 61-76), 51% (95% CI, 46-56.4), and 34% (95% CI, 21-49), respectively (P < .001). Increasing score was predictive of increased transplant-related mortality (TRM; P = .0017) but not of relapse (P = .12). The derived score was predictive of OS (P < .001) and TRM (P = .002) but not of relapse (P = .17) in the EBMT cohort as well. The proposed system was prognostic of survival in 2 large cohorts, CIBMTR and EBMT, and can easily be applied by clinicians consulting patients with MF about the transplantation outcomes.

Cryopreservation and storage patterns of hematopoietic progenitor stem cells for multiple myeloma.

Autologous hematopoietic stem cell transplantation (HCT) has been a standard of care treatment for eligible patients with newly diagnosed multiple myeloma (MM). Guidelines generally recommend hematopoietic progenitor cell (HPC) harvest for two potential HCT. There is a paucity of data reporting use of such collections in the era of novel approved therapies. In this single-center retrospective study, our goal was to determine the HPC utilization rate and costs associated with leukocytapheresis, collection, storage, and disposal to guide future HPC collection planning. We included 613 patients with MM who underwent HPC collection over a nine-year period. The patients were separated into four groups based on HPC utilization: 1) patients who never proceeded to HCT, or Harvest and Hold (14.8 %), 2) patients who proceeded to one HCT with banked HPC remaining (76.8 %), 3) patients who proceeded to one HCT without HPC remaining (5.1 %), and 4) patients who proceeded to two HCTs (3.3 %). After collection, 73.9 % of patients underwent HCT within 30 days. Of patients with banked HPC, defined as not undergoing HCT within 30 days of leukocytapheresis, the overall utilization rate was 14.9 %. At 2- and 5-years post HPC collection, utilization rate was 10.4 % and 11.5 %, respectively. In conclusion, our results suggest very low utilization of stored HPC, raising into question the current HPC collection targets. Given advances in MM therapy, as well as significant costs associated with harvest and storage, collection for unplanned future use warrants reconsideration. As a result of our analysis, our institution has reduced our HPC collection targets.

HLA Class I Genotype Is Associated with Relapse Risk after Allogeneic Stem Cell Transplantation for NPM1-Mutated Acute Myeloid Leukemia.

Mutation-bearing peptide ligands from mutated nucleophosmin-1 (NPM1) protein have been empirically found to be presented by HLA class I in acute myeloid leukemia (AML). We hypothesized that HLA genotype may impact allogeneic hematopoietic stem cell transplantation (allo-HCT) outcomes in NPM1-mutated AML owing to differences in antigen presentation. We evaluated the effect of the variable of predicted strong binding to mutated NPM1 peptides using HLA class I genotypes from matched donor-recipient pairs on transplant recipients' overall survival (OS) and disease-free survival (DFS) as part of the primary objectives and cumulative incidence of relapse and nonrelapse mortality (NRM) as part of secondary objectives. Baseline and outcome data reported to the Center for International Blood and Marrow Transplant Research from a study cohort of adult patients (n = 1020) with NPM1-mutated de novo AML in first (71%) or second (29%) complete remission undergoing 8/8 matched related (18%) or matched unrelated (82%) allo-HCT were analyzed retrospectively. Class I alleles from donor-recipient pairs were analyzed for predicted strong HLA binding to mutated NPM1 using netMHCpan 4.0. A total of 429 (42%) donor-recipient pairs were classified as having predicted strong-binding HLA alleles (SBHAs) to mutated NPM1. In multivariable analyses adjusting for clinical covariates, the presence of predicted SBHAs was associated with a lower risk of relapse (hazard ratio [HR], .72; 95% confidence interval [CI], .55 to .94; P = .015). OS (HR, .81; 95% CI, .67 to .98; P = .028) and DFS (HR, .84; 95% CI, .69 to 1.01; P = .070) showed a suggestion of better outcomes if predicted SBHAs were present but did not meet the prespecified P value of <.025. NRM did not differ (HR, 1.04; P = .740). These hypothesis-generating data support further exploration of HLA genotype-neoantigen interactions in the allo-HCT context.

Association between the choice of the conditioning regimen and outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis.

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment for myelofibrosis. However, the optimal conditioning regimen either with reduced-intensity conditioning (RIC) or myeloablative conditioning (MAC) is not well known. Using the Center for International Blood and Marrow Transplant Research database, we identified adults aged ≥18 years with myelofibrosis undergoing allo-HCT between 2008-2019 and analyzed the outcomes separately in the RIC and MAC cohorts based on the conditioning regimens used. Among 872 eligible patients, 493 underwent allo-HCT using RIC (fludarabine/ busulfan n=166, fludarabine/melphalan n=327) and 379 using MAC (fludarabine/busulfan n=247, busulfan/cyclophosphamide n=132). In multivariable analysis with RIC, fludarabine/melphalan was associated with inferior overall survival (hazard ratio [HR]=1.80; 95% confidenec interval [CI]: 1.15-2.81; P=0.009), higher early non-relapse mortality (HR=1.81; 95% CI: 1.12-2.91; P=0.01) and higher acute graft-versus-host disease (GvHD) (grade 2-4 HR=1.45; 95% CI: 1.03-2.03; P=0.03; grade 3-4 HR=2.21; 95%CI: 1.28-3.83; P=0.004) compared to fludarabine/busulfan. In the MAC setting, busulfan/cyclophosphamide was associated with a higher acute GvHD (grade 2-4 HR=2.33; 95% CI: 1.67-3.25; P<0.001; grade 3-4 HR=2.31; 95% CI: 1.52-3.52; P<0.001) and inferior GvHD-free relapse-free survival (GRFS) (HR=1.94; 95% CI: 1.49-2.53; P<0.001) as compared to fludarabine/busulfan. Hence, our study suggests that fludarabine/busulfan is associated with better outcomes in RIC (better overall survival, lower early non-relapse mortality, lower acute GvHD) and MAC (lower acute GvHD and better GRFS) in myelofibrosis.

Brexucabtagene Autoleucel for Relapsed or Refractory Mantle Cell Lymphoma in Standard-of-Care Practice: Results From the US Lymphoma CAR T Consortium.

PURPOSE: Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication. PATIENTS AND METHODS: Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines. RESULTS: Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis. CONCLUSION: In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.

Association of ABO mismatch with the outcomes of allogeneic hematopoietic cell transplantation for acute leukemia.

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). While many factors influence the outcomes of allo-HCT, the independent impact of donor-recipient ABO mismatching remains unclear. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we identified patients aged ≥18 years with AML or ALL who underwent allo-HCT between 2008 and 2018. Our objectives were to analyze the outcomes of allo-HCT based on the donor-recipient ABO status (match, minor mismatch, major mismatch, bidirectional mismatch). Among 4946 eligible patients, 2741 patients (55.4%) were ABO matched, 1030 patients (20.8%) had a minor ABO mismatch, 899 patients (18.1%) had a major ABO mismatch, and 276 patients (5.6%) had a bidirectional ABO mismatch. In multivariable analyses, compared to ABO matched allo-HCT, the presence of a major ABO mismatch was associated with worse overall survival (HR 1.16, 95% CI 1.05-1.29; p = 0.005), inferior platelet engraftment (HR 0.83, 95% CI 0.77-0.90; p < 0.001), and higher primary graft failure (HR 1.60, 95% CI 1.12-2.30, p = 0.01). Relapse, acute graft versus host disease (GVHD) grades III-IV and chronic GVHD were not significantly associated with ABO status. While donor age was not significantly associated with outcomes, older recipient age was associated with worse survival and non-relapse mortality. Our study demonstrates that donor-recipient ABO status is independently associated with survival and other post-transplantation outcomes in acute leukemia. This underscores the importance of considering the ABO status in donor selection algorithms and its impact in acute leukemia.

The mutational landscape in chronic myelomonocytic leukemia and its impact on allogeneic hematopoietic cell transplantation outcomes: a Center for Blood and Marrow Transplantation Research (CIBMTR) analysis.

Somatic mutations are recognized as an important prognostic factor in chronic myelomonocytic leukemia (CMML). However, limited data are available regarding their impact on outcomes after allogeneic hematopoietic cell transplantation (HCT). In this registry analysis conducted in collaboration with the Center for International Blood and Marrow Transplantation Registry database/sample repository, we identified 313 adult patients with CMML (median age: 64 years, range, 28- 77) who underwent allogeneic HCT during 2001-2017 and had an available biospecimen in the form of a peripheral blood sample obtained prior to the start of conditioning. In multivariate analysis, a CMML-specific prognostic scoring system (CPSS) score of intermediate-2 (HR=1.46, P=0.049) or high (HR=3.22, P=0.0004) correlated significantly with overall survival. When the molecularly informed CPSS-Mol prognostic model was applied, a high CPSS-Mol score (HR=2 P=0.0079) correlated significantly with overall survival. The most common somatic mutations were in ASXL1 (62%), TET2 (35%), KRAS/NRAS (33% combined), and SRSF2 (31%). DNMT3A and TP53 mutations were associated with decreased overall survival (HR=1.70 [95% CI: 1.11-2.60], P=0.0147 and HR=2.72 [95% CI: 1.37-5.39], P=0.0042, respectively) while DNMT3A, JAK2, and TP53 mutations were associated with decreased disease-free survival (HR=1.66 [95% CI: 1.11-2.49], P=0.0138, HR=1.79 [95% CI: 1.06-3.03], P=0.0293, and HR=2.94 [95% CI: 1.50-5.79], P=0.0018, respectively). The only mutation associated with increased relapse was TP53 (HR=2.94, P=0.0201). Nonetheless, the impact of TP53 mutations specifically should be interpreted cautiously given their rarity in CMML. We calculated the goodness of fit measured by Harrell's C-index for both the CPSS and CPSS-Mol, which were very similar. In summary, via registry data we have determined the mutational landscape in patients with CMML who underwent allogeneic HCT, and demonstrated an association between CPSS-Mol and transplant outcomes although without major improvement in the risk prediction beyond that provided by the CPSS.

Three-Year Follow-Up of KTE-X19 in Patients With Relapsed/Refractory Mantle Cell Lymphoma, Including High-Risk Subgroups, in the ZUMA-2 Study.

PURPOSE: Brexucabtagene autoleucel (KTE-X19) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is approved for the treatment of relapsed/refractory mantle cell lymphoma (MCL). Outcomes after a 3-year follow-up in the pivotal ZUMA-2 study of KTE-X19 in relapsed/refractory MCL are reported, including for subgroups by prior therapy (bendamustine and type of Bruton tyrosine kinase inhibitor [BTKi]) or high-risk characteristics. METHODS: Patients with relapsed/refractory MCL (one to five prior therapies, including prior BTKi exposure) received a single infusion of KTE-X19 (2 × 106 CAR T cells/kg). RESULTS: After a median follow-up of 35.6 months, the objective response rate among all 68 treated patients was 91% (95% CI, 81.8 to 96.7) with 68% complete responses (95% CI, 55.2 to 78.5); medians for duration of response, progression-free survival, and overall survival were 28.2 months (95% CI, 13.5 to 47.1), 25.8 months (95% CI, 9.6 to 47.6), and 46.6 months (95% CI, 24.9 to not estimable), respectively. Post hoc analyses showed that objective response rates and ongoing response rates were consistent among prespecified subgroups by prior BTKi exposure or high-risk characteristics. In an exploratory analysis, patients with prior bendamustine benefited from KTE-X19, but showed a trend toward attenuated T-cell functionality, with more impact of bendamustine given within 6 versus 12 months of leukapheresis. Late-onset toxicities were infrequent; only 3% of treatment-emergent adverse events of interest in ZUMA-2 occurred during this longer follow-up period. Translational assessments revealed associations with long-term benefits of KTE-X19 including high-peak CAR T-cell expansion in responders and the predictive value of minimal residual disease for relapse. CONCLUSION: These data, representing the longest follow-up of CAR T-cell therapy in patients with MCL to date, suggest that KTE-X19 induced durable long-term responses with manageable safety in patients with relapsed/refractory MCL and may also benefit those with high-risk characteristics.

Adapting the HCT-CI Definitions for Children, Adolescents, and Young Adults with Hematologic Malignancies Undergoing Allogeneic Hematopoietic Cell Transplantation.

Allogeneic hematopoietic cell transplantation is a curative procedure for hematologic malignancies but is associated with a significant risk of non-relapse mortality (NRM). The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) is a prognostic tool that discriminates this risk in all age groups. A recent survey of transplant physicians demonstrated that 79% of pediatric providers used the HCT-CI infrequently, and most reported concerns about its applicability in the younger population. We conducted a retrospective study using the Center for International Blood and Marrow Transplant Research database to examine the impact of expanded HCT-CI definitions on NRM in pediatric and young adult patients with hematologic malignancies. We included 5790 patients <40 years old receiving allogeneic transplants between 2008 and 2017 to examine broader definitions of comorbidities in the HCT-CI, including history of mechanical ventilation and fungal infection, estimated glomerular filtration rate, and body mass index (BMI) percentiles. Multivariable Fine-Gray models were created to determine the effect of each HCT-CI defining comorbidity and its modification on NRM and were used to develop 2 novel risk scores. We next developed the expanded HCT-CI for children and young adults (youth with malignancies; expanded ymHCT-CI), where 23% patients had an increased comorbidity score, compared to the HCT-CI. Comorbidities with hazard ratio < 1.2 were then removed to create the simplified HCT-CI for children and young adults (youth with malignancies; simplified ymHCT-CI), which demonstrated higher scores corresponded to a greater risk of NRM (P < .001). These novel comorbidity indexes with broader definitions are more relevant to pediatric and young adult patients, and prospective studies are needed to validate these in the younger patient population. It remains to be seen whether the development of these pediatric-specific and practical risk indexes increases their use by the pediatric transplant community.