Kim, Soyoung

Abstract Introduction: Axi-cel, an autologous anti-CD19 CAR T-cell therapy has shown high and durable response rates and a manageable safety profile among R/R FL pts in the ZUMA-5 trial (Jacobson et al. 2022; Neelapu et al. 2024). Evidence from real-world data showed favorable early outcomes in a broader population using CIBMTR data, with comparable outcomes by ZUMA-5 eligibility, age, lines of therapy (LOT), and prior bendamustine (benda) use (Jacobson et al. 2023). This study investigated long-term outcomes and the association between age, performance status, comorbidities, and therapies given prior to infusion among R/R FL pts treated with axi-cel. Methods: Pts with R/R FL who received commercial axi-cel between 03/2021–10/2023 in the US were identified from the CIBMTR® registry; pts without consent, with prior non-transplant cellular therapy, and FL grade 3B or 3A/3B unspecified or unknown were excluded. Descriptive analyses were done among all pts and by age at infusion (<65 vs ≥65 y), Karnofsky performance score (KPS), presence of hepatic, cardiovascular (CV), or moderate to severe pulmonary comorbidities, prior treatments (benda pre-leukapheresis, autologous hematopoietic stem cell transplant [autoHSCT]), and lymphodepletion (LD) therapy. Multivariable (MV) Cox and logistic regression were used to adjust for confounders. Results: In total, 238 pts from 68 centers were included (data cut-off October 2024). Median age at infusion was 61 yr (range, 29-83; ≥65 yr, 38%), and 79% were non-Hispanic White. KPS of pts was ≤70% (11%), 80% (35%), or 90-100% (54%); 2% had ECOG ≥2. Most (75%) had ≥1 clinically significant comorbidity (hepatic, 6%; CV, 15%; pulmonary, 18%). Median (min, max) prior LOT was 4 (1,13); 74% received benda pre-leukapheresis, and 6% had benda LD therapy. At a median follow-up of 24.1 months, objective response rate (ORR) was 96% (complete response [CR] rate, 91%). The 2-yr (95% CI) DOR, PFS, and OS were 70% (63-77), 64% (57-71), and 84% (78-89) respectively. Grade ≥3 cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 4% and 18% of pts (any grade, 74% and 42%), respectively. Prolonged cytopenias by day 30 occurred in 14% of pts (neutropenia [10%] and thrombocytopenia [8%]) while 29% had clinically significant infections at 6 months. Second primary malignancies occurred in 16 pts (7%), with 7 (2%) being therapy-related myeloid neoplasm. The leading primary causes of death (n=34) were relapse/progression (10; 29%), organ failure (7; 21%), and infection 5 (15%). Cumulative incidence of non-relapse mortality at 2-yr was 9%. Outcomes were generally comparable among age, autoHSCT, and comorbidity subgroups. However, effectiveness outcomes differed by prior benda use (Yes vs No): ORR (95% vs 98%); CR (88% vs 98%); DOR (65% vs 89%), PFS (58% vs 84%), and OS (82% vs 91%) at 2 years. By LD therapy (single agent benda vs cyclophosphamide + fludarabine [Cy + Flu]): the ORR was 93% vs 96%; CR rate was 57% vs 93%. On MV analysis, prior benda use was associated with (OR/HR [95% CI]): worse CR (0.02 [<0.01-0.43]), DOR (3.69 [1.51-9.02], and PFS (2.21 [1.12-4.38]). Pts given benda LD therapy had (OR/HR [95% CI]): worse CR rate (0.02 [<0.01-0.16]), DOR (7.59 [2.33-24.72]), and PFS (4.89 [1.79-13.39]) compared to those who received Cy + Flu. CRS and ICANS were lower among those with prior benda use (Yes vs No): any-grade CRS (70% vs 87%); Grade ≥3 CRS (3% vs 8%); any-grade ICANS (36% vs 61%); and grade ≥3 ICANS (17% vs 25%). By LD therapy (single agent benda vs Cy + Flu): the Grade ≥3 CRS and ≥3 ICANS were 0% vs 5% and 7% vs 19% respectively. Any-grade ICANS was higher among those aged ≥ 65 yr vs <65 yr (53% vs 35%). On MV analysis, pts who had prior benda use were less likely to have any-grade CRS (0.30 [0.12-0.75]), and any-grade ICANS (0.23 [0.11-0.50]. Pts ≥ 65 yr had higher any-grade ICANS (2.31 [1.18 – 4.50]). Summary/Conclusion: This long-term follow up of axi-cel in R/R FL shows durable responses and manageable safety similar to ZUMA-5. Outcomes among the elderly and those with comorbidities were generally comparable to the overall R/R FL population. Although benda use pre-leukapheresis was associated with less durable responses, we were unable to determine whether this association is limited to use close to axi-cel infusion, as data on timing of use was unavailable. The associations for benda LD should be interpreted with caution given the small sample size.

Abstract The cumulative impact of baseline comorbidities on outcomes of chimeric antigen receptor T-cell (CAR-T) therapy is not well established. Therefore, we developed and validated a Cellular Therapy Comorbidity Index (CT-CI) to predict outcomes following CD19-directed CAR-T therapy for large B-cell lymphoma (LBCL). Patients aged 18 or older receiving commercial CAR-T therapy for LBCL during 2017 to 2020 were selected from the Center for International Blood and Marrow Transplant Research registry. Patients were randomly assigned to training or validation cohorts. Comorbidities given weighted scores comprised the CT-CI, which was then validated for overall survival (OS) prognostication. A total of 1916 patients from 97 medical centers were included, with a median age of 64 years (19-91 years). About 70% of patients had comorbidities, such as cardiac disease (12%); diabetes (14%); hepatic dysfunction (mild, 8%; moderate to severe, 2%); psychiatric disturbance (18%); and pulmonary dysfunction (moderate, 15%; severe, 12%). The CT-CI was calculated, stratified patients in 3 categories, and was associated with increased mortality. Patients with higher CT-CI scores had worse OS (CT-CI 1: hazard ratio [HR], 1.37 [95% confidence interval [CI], 1.16-1.62; P< .001]; CT-CI 2: HR, 1.49 [95% CI, 1.17-1.89; P = .001]; CT-CI ≥ 3: HR, 2.55 [95% CI, 1.90-3.42; P< .001]). Higher CT-CI scores predicted treatment-related mortality and relapse. There was no correlation between the CT-CI score and CAR-T–related toxicities. The novel CT-CI score stratifies the effect of patient comorbidities on survival after CAR-T therapy and can be used for clinical decision-making and treatment selection in high-risk populations. However, comorbidities and fear of increased toxicity should not preclude patients from this effective therapy.

Abstract Brexucabtagene autoleucel (brexu-cel) is a chimeric antigen receptor T-cell therapy approved for relapsed/refractory mantle cell lymphoma (R/R MCL). Here, we report real-world effectiveness and safety outcomes of brexu-cel in a prospective study of patients with R/R MCL, including subgroups based on prior treatment with Bruton's tyrosine kinase inhibitor, bendamustine, or autologous hematopoietic cell transplant (auto-HCT) and number of prior therapy lines, using Center for International Blood and Marrow Transplant Research registry data. A total of 476 patients with R/R MCL who received brexu-cel between July 2020 and December 2022 were included in the analysis. With a median follow-up of 13.5 months, the overall response rate was 91% and complete response rate was 82%. One-year overall survival and progression-free survival rates were 76% and 63%, respectively. One-year cumulative incidence of nonrelapse mortality was 8%. Prior auto-HCT was associated with better duration of response within 6 months after infusion (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.28-0.85) but greater risk of immune effector cell–associated neurotoxicity syndrome (odds ratio [OR], 1.66; 95% CI, 1.06-2.60). Prior bendamustine was associated with increased risk of prolonged thrombocytopenia (OR, 1.90; 95% CI, 1.13-3.21). In patients with 1 to 2 prior therapy lines, relapse or progression was less frequent compared with those with ≥3 prior lines (HR, 0.64; 95% CI, 0.42-1.00). Collectively, our results suggest that real-world outcomes with brexu-cel were consistent with those of the ZUMA-2 trial, regardless of prior therapy type or number of prior therapy lines.

Abstract We evaluate the impact of donor types on outcomes of hematopoietic cell transplantation (HCT) in myelofibrosis, using the Center for International Blood and Marrow Transplant Research registry data for HCTs done between 2013 and 2019. In all 1597 patients, 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% of recipients of haploidentical HCT were non-White/Caucasian. Matched sibling donor (MSD)–HCTs were associated with superior overall survival (OS) in the first 3 months (haploidentical hazard ratio [HR], 5.80 [95% confidence interval (CI), 2.52-13.35]; matched unrelated (MUD) HR, 4.50 [95% CI, 2.24-9.03]; mismatched unrelated HR, 5.13 [95% CI, 1.44-18.31]; P < .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, MUD, and mismatched unrelated donor HCTs in the first 3 months. Donor type was not associated with differences in OS beyond 3 months after 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. Although MSD-HCTs were superior, there is no significant difference in HCT outcomes from haploidentical and MUDs. These results establish haploidentical HCT with posttransplantation cyclophosphamide as a viable option in myelofibrosis, especially for ethnic minorities underrepresented in the donor registries.

Background: Autologous CAR-T therapy targeting CD19 is an effective treatment for relapsed or refractory large B-cell lymphoma (LBCL). However, morbidity and mortality related to CAR-T toxicity remain significant concerns. This study aims to evaluate the patterns, risk factors, and implications of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) following CD19-CAR-T therapy in LBCL. Methods: This retrospective analysis includes 1916 LBCL patients treated with CD19-CAR-T cell therapy (axicabtagene-ciloleucel [axi-cel] 75% and tisagenlecleucel 25%) between 2018 and 2020 and reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). Patient demographics, baseline characteristics, treatment-related variables, and clinical outcomes were collected. The incidence, severity and timing of onset of CRS and ICANS (according to median time to onset) were analyzed, factors associated with these outcomes and their impact on overall survival as time dependent covariates were done using Cox Regression multivariate analyses. Results: The median age of the patients was 64 years, with a majority having a Karnofsky performance status (KPS) below 90% (61%) and not receiving bridging therapy (67%). CRS was observed in 75.1% of patients, with 9% experiencing severe CRS (grades ≥ 3). Similarly, 43% of patients experienced ICANS, with 20% having severe ICANS (grade ≥ 3). The median time to toxicity was shorter for CRS (4 days) compared to ICANS (7 days). Nearly all the patients who developed ICANS also experienced CRS (98%; ), and the correlation between these two events and respective severities are shown in the Figure 1a. In the multivariate analyses, factors associated with development of CRS were gender (women, Odds ratio [OR] 1.39, 95% confidence interval [CI] 1.10- 1.76, p=0.006), high LDH at time of infusion (OR 1.56; 95% CI 1.22 - 2.00, p=0.002) and product (axi-cel OR 4.60, 95% CI 3.56 -5.81, p<0.001). Factors associated with the development of ICANS included age (> 65 years, OR 1.83; 1.50-2.24, p<0.001), KPS (<80%, OR 2.48; 1.88-3.27, p<0.001), disease status at infusion (treatment resistant disease, OR 1.98; 1.09-3.58, p=0.024; and untreated relapse OR 2.62, 1.35-5.10, p=0.004) and product (axi-cel, OR 5.85; 4.47-7.64, p<0.0001). Factors associated with severe and early onset CRS and ICANS are listed in the table below. The median follow-up of 14.2 months, the estimated 12-month overall survival, progression-free survival (PFS), and treatment-related mortality were 61.6% (95% CI: 59.4-63.9), 42.2% (39.9-44.5), and 4.3% (3.4-5.3), respectively. Overall CRS, early onset CRS and overall ICANS were not associated with higher mortality, however grade >3 CRS (HR 1.79; 1.41-2.28, p<0.001), grade >3 ICANS (hazard ratio [HR] 1.34; 95% CI 1.13-1.59, p=0.002) and early onset ICANS (<7 days, HR 1.23; 1.05-1.44, p=0.01) were associated with higher mortality. The impact of severe CRS on survival are shown in the landmark analysis at 30 days from infusion in the figure 1B. Conclusion: In the largest analysis of CD19-CAR-T cell therapy toxicities to date, we observed a high burden of CRS and ICANS among LBCL patients. The CAR T cell product type was consistently associated with higher incidence, shorter onset and higher severity of both toxicities. High LDH, older age and low performance score also influence the severity and onset of these outcomes. Additionally, patients who developed higher grades of CRS/ICANS and earlier onset ICANS had a higher mortality, stressing the need to develop novel strategies to mitigate the incidence and optimize management of these patients to improve their outcomes.

Abstract Background: CD19 CAR T cell therapies have demonstrated high initial complete remission (CR) rates of 70-80% in relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL) with durable remissions observed in a subset of patients. Despite the remarkable initial CR rate, relapses occur in 20-45% of patients and with increasing use of CD19 CAR T cell therapies in ALL, a key remaining clinical question is the role of post-CAR HCT. Methods: Patients up to 26 years treated with the commercial (i.e., tisagenlecleucel) or investigational CD19 CAR T cell products from 2014 to 2019 in the United States were included. The objectives were to examine the impact of post-CAR HCT on mortality, disease-free survival (DFS), leukemia relapse, GVHD and transplant related mortality among HCT recipients. The intent of HCT was analyzed as consolidation when there was no evidence of post-CAR T cell relapse prior to HCT. Cox regression multivariable analysis used HCT as time-dependent variable along with age, performance status and time from diagnosis to CAR-T cell infusion to evaluate its impact on outcomes. Results: We identified 347 patients who received CD19 CAR T cells from 86 centers. Median age was 13 (range, 0.4-26 years) with 39% of patients from Hispanic or Latino ethnic origin. Patients were high risk and heavily pretreated; 56% had poor cytogenetics, 51% had ≥3 line of prior therapies and 34% had prior HCT. Most of the patients (74%) received tisagenlecleucel. Disease burden at the time of CAR T cell infusion included morphologic disease (≥5% bone marrow blasts) (65%), measurable residual disease (MRD) positive (16%) and negative CR (18%). CRS of all grades was observed in 57.6% and grade 3-4 CRS in 13%; neurotoxicity of all grades was observed in 25% and grade 3-4 in 8%. With a median follow-up of 12.7 months (range, 2.2-60.3), DFS at 3, 6 and 12 months following CAR T cell infusion was 80.9% % (95% CI: 76.6%-84.9%), 71.2% (95% CI: 66.1%-76.0%) and 57.6% (95% CI: 51.8%-63.3%), respectively. OS at 3, 6 and 12 months was 93.6% (95% CI: 90.8%-96.0%), 89.8% (95% CI: 86.4%-92.8%) and 79.4% (95% CI: 74.7%-83.6%), respectively. Incidences of relapse without censoring at subsequent HCT at month 3, 6 and 12 were 18.5% (95% CI: 14.5%-22.8%), 28.2% (95% CI: 23.5%-33.3%), and 40.6% (95% CI: 35.0%-46.3%), respectively. Of the 347 patients who received CD19 CAR therapy, 62 patients (18%) had subsequent HCT in CR as a consolidation post-CAR with a median time from CAR T to HCT of 4.7 months (range, 1.1-18.6). 36% had a prior HCT (i.e., pre-CAR), 87% received myeloablative regimen and among the 57 patients with MRD evaluation 56 were negative (98%). Frequencies of post-CAR HCT did not change during the 5-year study period. Overall, transplant related mortality (TRM) at month 6 was 8.9% (95% CI: 3.6-16.1), and grade 2-4 acute GvHD was observed in 38.0% (95% CI: 28.4-48.2) of patients at month 6. Post-CAR HCT used as a consolidation was associated with lower relapse (hazard ratio (HR) 0.37; p=0.037) but no significant impact on mortality (HR 0.75, p=0.51) or DFS (HR=0.46, p=0.057). When accounting for any HCT performed after CAR T cell, HCT was associated with higher mortality (Figure). Conclusions: This is the largest clinical series to date examining the impact of post-CAR HCT on clinical outcome of R/R B-ALL patients. We found that 18% of the patients had post-CAR HCT as a consolidation therapy with a favorable safety profile of 8.9% TRM rate despite a prior transplant rate of 36%. Consolidation HCT after CAR T cell resulted in significant reduction in leukemia relapse with a trend towards better DFS. Consolidation HCT seem safe and incurred a benefit by reducing disease relapse. Further studies in understanding the role of consolidation HCT as planned, or post-CAR T cell response-based strategy or treatment for early B-cell recovery are needed to further define the best candidates for HCT after tisagenlecleucel . Figure 1 Figure 1. Disclosures Park: BMS: Consultancy; Affyimmune: Consultancy; Kite Pharma: Consultancy; Curocel: Consultancy; Novartis: Consultancy; Minerva: Consultancy; Innate Pharma: Consultancy; PrecisionBio: Consultancy; Intellia: Consultancy; Amgen: Consultancy; Autolus: Consultancy; Servier: Consultancy; Artiva: Consultancy; Kura Oncology: Consultancy. Nikiforow: Kite/Gilead: Other: ad HOC Advisory Boards; Novartis: Other: ad Hoc Advisory Boards; Iovance: Other: ad Hoc Advisory Boards; Glaxo Smith Kline (GSK): Other: ad Hoc Advisory Boards. Hu: Kite/Gilead: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Ahmed: Merck: Research Funding; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seagen: Research Funding; Xencor: Research Funding. Badar: Pfizer Hematology-Oncology: Membership on an entity's Board of Directors or advisory committees. Cairo: Servier: Speakers Bureau; Sanofi: Speakers Bureau; Amgen: Speakers Bureau; Jazz Pharmaceutical: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sobi: Speakers Bureau; Omeros: Membership on an entity's Board of Directors or advisory committees; Nektar: Membership on an entity's Board of Directors or advisory committees. Dholaria: Janssen: Research Funding; Takeda: Research Funding; Jazz: Speakers Bureau; MEI: Research Funding; Pfizer: Research Funding; Angiocrine: Research Funding; Poseida: Research Funding; Celgene: Speakers Bureau. Grover: Kite: Other: Advisory Board; Genentech: Research Funding; ADC: Other: Advisory Board; Tessa: Consultancy; Novartis: Consultancy. Locke: Gerson Lehrman Group: Consultancy; Emerging Therapy Solutions: Consultancy; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Calibr: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Wugen: Consultancy, Other; Legend Biotech: Consultancy, Other; Janssen: Consultancy, Other: Scientific Advisory Role; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; Novartis: Consultancy, Other, Research Funding; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Takeda: Consultancy, Other; EcoR1: Consultancy; Cowen: Consultancy; Umoja: Consultancy, Other; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding. Murthy: CRISPR Therapeutics: Research Funding. Mussetti: GILEAD: Other: Clinical trials participation, Research Funding; TAKEDA: Honoraria; NOVARTIS: Honoraria, Other: Clinical trials participation. Pulsipher: Jasper Therapeutics: Honoraria; Adaptive: Research Funding; Equillium: Membership on an entity's Board of Directors or advisory committees. Qayed: Novartis: Membership on an entity's Board of Directors or advisory committees; Medexus: Membership on an entity's Board of Directors or advisory committees; Mesoblast: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; BMS: Other. Reshef: Gilead, BMS, Precision, Immatics, Atara, Takeda, Shire, Pharmacyclics, Incyte: Research Funding; Gilead and Novartis: Honoraria; Bayer, BMS, Regeneron, TScan, Synthekine, Atara, Jasper: Consultancy. Rizzieri: Kite: Honoraria, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Acrotech: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; AROG: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Celltrion: Membership on an entity's Board of Directors or advisory committees; Mustang: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria; Pharmacyclics: Honoraria. Sharma: Vertex Pharmaceuticals/CRISPR Therapeutics: Other: Salary support paid to institution; Medexus Inc: Consultancy; CRISPR Therapeutics: Other, Research Funding; Vindico Medical Education: Honoraria; Spotlight Therapeutics: Consultancy; Novartis: Other: Salary support paid to institution. Schultz: BMS DSMB: Other: payment; Sobi: Membership on an entity's Board of Directors or advisory committees. Turtle: Century Therapeutics Ad hoc advisory boards (last 12 months): Nektar Therapeutics, Allogene, PACT Pharma, Astra Zeneca, Amgen: Membership on an entity's Board of Directors or advisory committees; Precision Biosciences: Membership on an entity's Board of Directors or advisory committees; Eureka Therapeutics: Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Membership on an entity's Board of Directors or advisory committees; T-CURX: Membership on an entity's Board of Directors or advisory committees; Myeloid Therapeutics: Membership on an entity's Board of Directors or advisory committees; ArsenalBio: Membership on an entity's Board of Directors or advisory committees; Minerva: Other; Nektar Therapeutics: Other; Juno Therapeutics/BMS: Other: Payments, Patents & Royalties: Patent licensed to Juno Therapeutics.; Precision Biosciences, Eureka Therapeutics, Caribou Biosciences, Myeloid Therapeutics, ArsenalBio: Current holder of stock options in a privately-held company. Pasquini: Kite Pharma: Research Funding; Novartis: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; GlaxoSmithKline: Research Funding. Perales: MorphoSys: Honoraria; Cidara: Honoraria; Bristol-Myers Squibb: Honoraria; Miltenyi Biotec: Honoraria, Other; Sellas Life Sciences: Honoraria; Takeda: Honoraria; Karyopharm: Honoraria; Celgene: Honoraria; Omeros: Honoraria; Nektar Therapeutics: Honoraria, Other; Equilium: Honoraria; Novartis: Honoraria, Other; NexImmune: Honoraria; Incyte: Honoraria, Other; Kite/Gilead: Honoraria, Other; Merck: Honoraria; Servier: Honoraria; Medigene: Honoraria.

Abstract Comparative outcomes of allogeneic hematopoietic cell transplantation (HCT) for BCR-ABL1− myeloproliferative neoplasms (MPNs) in blast phase (MPN-BP) vs de novo acute myeloid leukemia (AML), and AML with prior myelodysplastic syndromes (MDSs; post-MDS AML), are unknown. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we compared HCT outcomes in 177 MPN-BP patients with 4749 patients with de novo AML, and 1104 patients with post-MDS AML, using multivariate regression analysis in 2 separate comparisons. In a multivariate Cox model, no difference in overall survival (OS) or relapse was observed in patients with MPN-BP vs de novo AML with active leukemia at HCT. Patients with MPN-BP in remission had inferior OS in comparison with de novo AML in remission (hazard ratio [HR], 1.40 [95% confidence interval [CI], 1.12-1.76]) due to higher relapse rate (HR, 2.18 [95% CI, 1.69-2.80]). MPN-BP patients had inferior OS (HR, 1.19 [95% CI, 1.00-1.43]) and increased relapse (HR, 1.60 [95% CI, 1.31-1.96]) compared with post-MDS AML. Poor-risk cytogenetics were associated with increased relapse in both comparisons. Peripheral blood grafts were associated with decreased relapse in MPN-BP and post-MDS AML (HR, 0.70 [95% CI, 0.57-0.86]). Nonrelapse mortality (NRM) was similar between MPN-BP vs de novo AML, and MPN-BP vs post-MDS AML. Total-body irradiation–based myeloablative conditioning was associated with higher NRM in both comparisons. Survival of MPN-BP after HCT is inferior to de novo AML in remission and post-MDS AML due to increased relapse. Relapse-prevention strategies are required to optimize HCT outcomes in MPN-BP.

Abstract There is marked paucity of data regarding late effects in adolescents and young adults (AYAs) who undergo myeloablative conditioning (MAC) allogeneic hematopoietic cell transplantation (HCT) for acute myeloid leukemia (AML). We evaluated late effects and survival in 826 1-year disease-free survivors of MAC HCT for AYA AML, with an additional focus on comparing late effects based upon MAC type (total body irradiation [TBI] vs high-dose chemotherapy only). The estimated 10-year cumulative incidence of subsequent neoplasms was 4% (95% confidence interval [CI], 2%-6%); 10-year cumulative incidence of nonmalignant late effects included gonadal dysfunction (10%; 95% CI, 8%-13%), cataracts (10%; 95% CI, 7%-13%), avascular necrosis (8%; 95% CI, 5%-10%), diabetes mellitus (5%; 95% CI, 3%-7%), and hypothyroidism (3%; 95% CI, 2%-5%). Receipt of TBI was independently associated with a higher risk of cataracts only (hazard ratio [HR], 4.98; P < .0001) whereas chronic graft-versus-host disease (cGVHD) was associated with an increased risk of cataracts (HR, 3.22; P = .0006), avascular necrosis (HR, 2.49; P = .006), and diabetes mellitus (HR, 3.36; P = .03). Estimated 10-year overall survival and leukemia-free survival were 73% and 70%, respectively, and did not differ on the basis of conditioning type. In conclusion, late effects among survivors of MAC HCT for AYA AML are frequent and are more closely linked to cGVHD than type of conditioning.