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765 citation(s) found for "Litzow, Mark".

Sparse whole genome sequencing and machine learning of AML genomes reveals novel, clinically relevant genetics.
Baslan, Timour , Belleau, Pascal, Zhang, Yanming , Sun, Zhuoxin , Kleppe, Maria, Paietta, Elisabeth , Cripe, Larry D., Fernández, Hugo F. , Tallman, Martin S. , Rowe, Jacob M. , Litzow, Mark R. , Dimitrova, Nevenka , Luger, Selina M. , Deschênes, Astrid , Garrett-Bakelman, Francine E. , Lazarus, Hillard M. , Melnick, Ari , Levine, Ross L. , Krasnitz, Alexander , Lowe, Scott W.

Mayo Clinic

Blood | December 5, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 5263-5263

10.1182/blood-2025-5263 Get It

Abstract Copy Number Alterations (CNAs), including chromosomal gains and losses, shape the genetics and clinical management of acute myeloid leukemia (AML), particularly in complex karyotypes (e.g. CK-AML). Traditionally, AML associated CNAs have been studied using cytogenetic approaches, i.e., karyotyping, that are limited in resolution and sensitivity. Here, low-coverage, sparse whole genome sequencing followed by machine learning applied to over 600 AML patient samples (ECOG-ARCIN trials: E1900, E3999) reveals novel genetic, biologic, and clinical correlates in AML disease. We find that multi-variate Cox-regression analysis applied to the data identifies select patients exhibiting focal and cryptic hemizygous deletions at 17q, 21q, and 3p, in otherwise diploid genomes, associate with inferior survival compared to other patients (median overall survival; OS = 65.5 compared to 421 days, Chi-square test pval=6x10-11), independent of factors such as age, treatment, and karyotype complexity status. In addition, we confirm that amplifications at 11q23, encoding the KM2TA gene, are associated with inferior outcome, and further identify unique breakpoint event features as well as transcriptional signatures suggestive of distinctive KM2TA-translocation independent biology. Applying machine learning approaches to the data, more specifically Non-negative Matrix Factorization (NMF), we develop a prognostic model that captures clinically adverse, cryptic variation such as focal 5q deletions, missed by conventional chromosome analysis and thereby, adds novel, complementary information to traditional, cytogenetic based risk-stratification (e.g. ELN). The model also associates gain of chromosome 8 in Intermediate risk patients with worse outcome compared to other Intermediate risk patients (median OS = 186 compared to 446 days, Chi-square test pval=0.005) and identifies a subgroup of patients within the adverse risk category that lack deletions on chromosomes 5, 7, and 17, and that fare better than the rest of the adverse risk patients (median OS = 188 compared to 97.5 days, Chi-square test pval=0.02), likely reflecting previously identified “atypical” CK-AML patients. Last, we develop a prognostic classifier based on a combination of Neural-Network and Random-Forest based learning, that predicts disease outcome with high accuracy and is based on a three genomic feature list on chromosome bands 5q31.2, 7q31.33, and 8q24, suggesting potential for clinical implementation. Altogether, our results show that low coverage, sparse whole genome sequencing combined with advanced learning methods can be applied clinically to support the diagnosis and clinical management of AML disease as well as serve as a powerful tool to further a basic understanding of the genetics and biology of CNAs in myeloid neoplasms and other cancers.
Fetal hemoglobin dysregulation in inherited and acquired bone marrow failure syndromes
Heigh, Victoria, Abdelmagid, Maymona, Ongie, Laura, McCullough, Kristen, Fernandez, Jenna, Lasho, Terra, Finke, Christy, Srinivasan, Anand, Kohorst, Mira, Ferdjallah, Asmaa, Hogan, William, Go, Ronald, Dingli, David, Gangat, Naseema, Al-Kali, Aref, Begna, Kebede, Alkhateeb, Hassan, Shah, Mithun, Litzow, Mark, Torghabeh, Mehrdad Hefazi, Matin, Aasiya, Reichard, Kaaren, Dalland, Joanna, Kusne, Yael, Foran, James, Ferrer, Alejandro, Patnaik, Mrinal, Mangaonkar, Abhishek, Heigh, Victoria, Abdelmagid, Maymona, Ongie, Laura, McCullough, Kristen, Fernandez, Jenna, Lasho, Terra, Finke, Christy, Srinivasan, Anand, Kohorst, Mira, Ferdjallah, Asmaa, Hogan, William, Go, Ronald, Dingli, David, Gangat, Naseema, Al-Kali, Aref, Begna, Kebede, Alkhateeb, Hassan, Shah, Mithun, Litzow, Mark, Torghabeh, Mehrdad Hefazi, Matin, Aasiya, Reichard, Kaaren, Dalland, Joanna, Kusne, Yael, Foran, James, Ferrer, Alejandro, Patnaik, Mrinal, Mangaonkar, Abhishek

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 6750-6750

10.1182/blood-2025-6750 Get It

Abstract Introduction: Inherited & acquired bone marrow failure syndromes (BMFS) have “stress erythropoiesis” with macrocytic anemia, elevated fetal hemoglobin (HbF) & erythropoietin (EPO) levels. The degree of HbF elevation & its capacity to discriminate between patients with inherited & acquired BMFS needs to be systemically studied. Genetic testing is often delayed & it is important to establish an early clinical diagnosis to make clinical decisions such as initiation of immunosuppressive therapy. Methods: After institutional review board approval, we compiled a clinically & genetically well-annotated cohort of patients with BMFS evaluated at Mayo Clinic. All patients were required to have at least cytopenia(s) & evidence of low or variable bone marrow cellularity upon a bone marrow evaluation. Patients with pre-clonal or malignant disorders were excluded. Clinical diagnoses were independently verified for accuracy. Detailed clinical & laboratory features were recorded. Germline genetic testing was performed as clinically appropriate on peripheral blood or bone marrow samples through targeted panels. Distribution of continuous variables was statistically compared using nonparametric (Mann-Whitney or Kruskal-Wallis) tests, while nominal variables were compared using the Chi-Square test. Kaplan-Meier estimate of overall survival (OS) was computed from the date of diagnosis to date of death or last follow-up (also censored at the time of allogeneic hematopoietic stem cell transplant). Results: Between years 1998 - 2023, 129 patients met criteria for inclusion in the study. Among these, clinical diagnoses included immune-mediated aplastic anemia (AA, n=56, 43%, 21% severe or very severe as per the Camitta criteria), telomere biology disorders (TBD, n=37, 29%), Fanconi anemia (n=10, 8%), GATA2 haploinsufficiency (n=8, 6%), Diamond-Blackfan anemia (DBA, n=2, 2%), deficiency of adenosine deaminase-2 (DADA2, n=2, 2%), congenital dyserythropoietic anemia (CDA, n=1, 1%), congential amegakaryocytic thrombocytopenia (CAMT, n=1, 1%), Schwachman-Diamond syndrome (n=1, 1%) & undefined (n=11, 9%). Among the inherited group, 63% had an identifiable germline pathogenic variant (most commonly, TERT/TERC 30%, FANC group 25% & GATA2 15%) with the rest diagnosed on a clinical basis. Elevated HbF >1% was noted in 79% of all BMFS patients; 83% AA, 70% TBD, 50% in DADA2 & 67% in undefined patients (no data was available for other inherited subtypes). In patients with an elevated HbF, absolute monocyte count (p=0.04) was significantly higher; however, there were no other significant associations with variables at diagnosis such as hemoglobin (p=0.5), white blood cell count (WBC, p=0.14), absolute neutrophil count (p=0.5), platelet count (p=0.7), mean corpuscular volume (MCV, p=0.2), absolute lymphocyte count (p=0.1), absolute reticulocyte count (p=0.4), EPO level (p=0.3), presence of a PNH clone (p=0.2), or presence of a germline variant (p=0.3). When diseases were grouped into inherited & acquired (AA) subgroups, median HbF was not significantly different (median%, 4.5 versus 2.3, p=0.4), with elevated HbF (>1%) in 75% versus 83% (p=0.6) patients respectively. On the other hand, minor PNH clone (>0.1% in at least two cell types) was detectable in the acquired group only (0 versus 55%, p<0.0001). Similarly, acquired group had a shorter (<3 months) onset of cytopenias preceding diagnosis (P<0.0001), with no significant differences in MCV (p=0.2), marrow dysplasia (p=0.09) or atypia (p=0.6), & splenomegaly (p=0.9). At median follow-up of 7 years, Kaplan-Meier estimate of transplant-censored median OS was lower in inherited versus acquired group (16 years versus median not reached, p=0.02). Elevated HbF did not significantly predict adverse OS in either group. Conclusions: Fetal hemoglobin is elevated in both patients with inherited & acquired (aplastic anemia) BMFS. When compared to established variables, elevated HbF has neither diagnostic utility nor prognostic relevance in predicting adverse outcomes. On the other hand, onset of cytopenias and presence of a minor PNH clone are both useful clinical variables in differentiating patients with inherited from acquired BMFS. Our data offers practical clinical utility in making early treatment decisions for patients with BMFS.
Effect of FLT3 maintenance in older FLT3-ITD+ adults undergoing allogeneic HCT. a post hoc analysis of BMT CTN 1506
Abedin, Sameem , Baidoo, Victor, Szabo, Aniko, Jones, Richard J. , Singh, Anurag K. , Litzow, Mark R. , Papadopoulos, Esperanza B. , Perl, Alexander E. , Soiffer, Robert J. , Üstün, Celalettin , Oshima, Masumi Ueda, Vasu, Sumithira , Solh, Melhem , Mishra, Asmita , Muffly, Lori , Stelljes, Matthias , Onozawa, Masahiro , Chen, Caroline , Hasabou, Nahla, Rosales, Mathew, Gill, Stanley C. , Nuthethi, Rishita, King, Denise , Mendizabal, Adam , Horowitz, Mary, Chen, Yi‐Bin , Levis, Mark J., Muffly, Lori , Abedin, Sameem , Litzow, Mark R. , Wingard, John R. , Oshima, Masumi Ueda, Uy, Geoffrey L. , Waller, Edmund K. , Kim, Hee-Je , Najima, Yuho , Rosales, Mathew, Hill, Jason E. , King, Denise, Devine, Steven M. , Levis, Mark J. , Hamadani, Mehdi

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 170-170

10.1182/blood-2025-170 Get It

Abstract INTRODUCTION Allogeneic hematopoietic cell transplantation (alloHCT) is indicated in patients (pts) with FLT3-ITD mutated AML. The randomized BMT CTN 1506 trial (Levis et al. JCO) demonstrated that maintenance with FLT3 inhibitor gilteritinib (gilt) significantly improved relapse-free survival (RFS) among pts with detectable peri-alloHCT minimal residual disease (MRD) but was also associated with a greater degree of myelosuppression and infections. In older pts, aged >60 years, increasing post-HCT toxicity may adversely impact outcomes. On this basis, we performed a post-hoc analysis of pts aged > 60 years enrolled onto BMT CTN 1506 to examine the impact of gilteritinib maintenance in older pts. METHODS Pts ≥60 years randomized on BMT CTN 1506 (gilt=47, placebo=57; N=104) were included. The primary endpoint of this post-hoc analysis was RFS. We additionally assessed overall survival (OS), incidence of relapse, non-relapse mortality (NRM) in all pts and in pts with detectable MRD. RESULTS Baseline characteristics were balanced. Age was similar (65.2 vs 64.7 years; p = 0.12), as was prior TKI exposure, and NPM1 mutation status. Myeloablative conditioning (MAC) was used in 8 (17%) pts randomized to gilt and 18 (32%) pts randomized to placebo (p=0.08). Median f/u of survivors was 43.8 months (range:1-61 mo.). Estimated RFS and OS at 48 months were not different between groups (RFS: gilt: 57.0%, 95%CI 44.1-73.7%, placebo: 57.1%, 95%CI 45.4-71.8%; OS: gilt: 56.9%, 95%CI 42.9-46.7%, placebo: 58.4%, 95%CI 46.7-73.1%). While gilt assignment did not affect survival, several predictors of poorer survival were identified including use of reduced intensity conditioning (RIC) (HR = 3.46; p = 0.014), use of calcineurin inhibitor/MTX for graft-vs-host disease (GVHD) prophylaxis (HR = 2.29; p = 0.041), high-risk cytogenetics (HR = 2.64; p = 0.021), and MRD (+) pre-HCT (HR = 2.29; p = 0.018). Finally, relative to gilt assignment, opposing rates of relapse and NRM were observed. The incidence of relapse was lower with gilt (16%, 95%CI 6.8-28% vs 32%, 95%CI 20-45%, p=0.046) but NRM was higher (27%, 95%CI 15-41% vs 11%, 95% CI 4.3-21%, p=0.033). We next analyzed the 49 pts (gilt=22, placebo=27) with detectable peri-HCT MRD. RFS and OS again were not different (RFS: gilt: 44.4%, 95%CI 27.1-72.7%, placebo: 43.8%, 95%CI 28.4-67.5%, OS: gilt: 49.2%,95%CI, 31.3-77.4%, placebo: 55.6%, 95%CI 39.4-77.8%). The incidence of relapse trended lower in gilt pts (25%, 95%CI, 5.3-44.7% vs 45% (95%CI, 25-63%), p=0.2) while NRM trended higher (31%, 95%CI 12-52% vs 11%, 95%CI, 2.7-26%, p=0.12). Seventeen (36%) patients completed planned 2 year maintenance with gilt compared to 29 (51%) completing therapy with placebo. Median time on gilt was 13.2 months. The most common reason for discontinuation was adverse events (n=19, 40%), of which cytopenias (n=8) and infections (n=4) were most frequent. Non-relapse causes of death among gilt treated pts included infections (n=8), intracranial hemorrhage related to thrombocytopenia (n=1), second cancer (n=1), and Guillain-Barre syndrome (n=1). Most infections (n=5) were attributed to GVHD as an underlying cause. CONCLUSION Among pts aged ≥60 years, gilt maintenance did not improve RFS or OS. Gilt use was associated with reduced relapse regardless of peri-HCT MRD status demonstrating disease effect; however, higher NRM limited overall benefit. In older FLT3 mutated pts, employing strategies to mitigate HCT related toxicity, e.g. alternative GVHD prophylaxis strategies, may better accommodate use of maintenance therapy including gilt. Lower doses of gilt (particularly with azole co-use) may be worth exploring to mitigate drug AEs, improve compliance, thus further improving benefit.
Impact of therapy delays on outcomes in adults with BCR::ABL1 negative b-lineage acute lymphoblastic leukemia (ALL) in the ECOG-ACRIN E1910 trial randomized to conventional chemotherapy +/- blinatumomab
Bhatnagar, Bhavana , Sun, Zhuoxin , Mattison, Ryan J. , Paietta, Elisabeth, Zhang, Yanming , Racevskis, Janis, Rowe, Jacob M. , Wieduwilt, Matthew J. , Liedtke, Michaela , Bergeron, Julie , Pratz, Keith W. , Dinner, Shira, Gore, Steven D. , Jeyakumar, Deepa , Patel, Shejal, Elliott, Michelle A. , Vachhani, Pankit , Roy, Rupali , Little, Richard F. , Stone, Richard M. , Luger, Selina M. , Tallman, Martin S. , Litzow, Mark R. , Lazarus, Hillard M. , Arber, Daniel A. , Wood, Brent L. , Frey, Noelle V. , Atallah, Ehab , Uy, Geoffrey L. , Lin, Tara L. , Willman, Cheryl L. , Podoltsev, Nikolai , DeAngelo, Daniel J. , Advani, Anjali S. , Tzachanis, Dimitrios , Sharon, Elad , Erba, Harry Paul , Mullighan, Charles G.

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 1549-1549

10.1182/blood-2025-1549 Get It

Abstract Background: The addition of the CD19/CD3 bispecific T-cell engager, blinatumomab, to standard consolidation chemotherapy in adults with ALL who achieved a measurable residual disease negative (MRDneg) remission (CR), demonstrated an improvement in 3-year overall survival (OS, 85% vs 68%, HR 0.41, P=0.002) and 3-year relapse-free survival (RFS, 80% vs 64%, HR 0.53) compared to conventional chemotherapy in the ECOG-ACRIN E1910 study (Litzow et al, NEJM 2024). Given the complex therapy in this study, treatment delays and modifications are expected. We herein explored the impact of such delays on patient outcomes. Methods: In the phase 3 ECOG-ACRIN E1910 trial (NCT02003222), adults aged 30-70 years with newly diagnosedALL who had achieved MRDneg CR following induction and intensification were randomized to consolidation chemotherapy with blinatumomab (blina arm) or chemotherapy alone (chemo arm). We examined the association between the timing of the initiation of maintenance therapy and OS and RFS. The expected duration of consolidation was 252 days vs 126 days for patients on the blina and chemo arms, respectively. For this analysis, participants were classified into two groups (no/short delay or long delay) depending on whether they started on time/before or after the median time between the beginning of consolidation and start of maintenance therapy for their treatment group (medians: 335 days, range, 181-457 days vs 176 days, range, 139-265 days for blina and chemo arms, respectively). Multivariate analyses of OS and RFS were performed to examine the effect of no/short delay vs. long delay in starting maintenance. Patients were stratified according to their assigned consolidation treatment arm, and the models were further adjusted for age, sex, white blood cell count, platelets, hemoglobin, peripheral blood blasts, bone marrow blasts, performance status and genetic-genomic risk at diagnosis. Results: Of the 488 patients enrolled, 224 MRDneg patients were randomized to consolidation chemotherapy with or without blinatumomab and 135 of the 224 went on to maintenance therapy on study (N= 66 on blina arm and 69 on chemo arm, respectively). The median follow-up from the time of maintenance registration was 43.4 months. There were no significant differences in baseline characteristics between patients in either arm who experienced no/short delay or long delay. In the blina group, 60 of 66 patients (90.9%) received all 8 cycles of consolidation therapy of which 31 (45.6%) had long delays. Sixty-eight of 69 patients on the chemo arm (98.5%) received all cycles of consolidation therapy, of which 34 (50%) had a long delay. Strikingly, patients who had a long delay before initiation of maintenance had a significant improvement in OS in multivariate analysis compared to patients who had no/short delay (HR 0.31, 95% CI: 0.11-0.91; P =0.03). However, within each treatment group, OS benefit did not reach statistical significance (blina arm: HR 0.04, 95% CI: 0.001-1.64; P =0.09; chemo arm: HR 0.32, 95% CI: 0.08-1.38; P =0.13). Similar results were observed for RFS in multivariate analysis (HR 0.40, 95% CI: 0.16-1.01; P =0.05), though this impact on improved RFS was noted in the chemo arm but not in blinatumomab treated patients (blina arm: HR 0.56, 95% CI: 0.10-3.24; P =0.52; chemo arm: HR 0.19, 95% CI: 0.04-0.83; P=0.03). Additionally, patients who had no/short delay before starting maintenance experienced a longer median duration of maintenance treatment (blina arm, 548 days; chemo arm, 708 days) compared to patients who had a long delay (blina arm 488 days; chemo arm 598 days) before initiation of maintenance (P=0.0008). Conclusion: In the phase 3 randomized ECOG-ACRIN E1910 clinical trial, long delays between initiation of consolidation therapy and start of maintenance therapy were associated with improved OS compared to no/short delays. However, within each treatment group (blina or chemo), no significant difference of OS was observed. We postulate that these longer delays allowed more patients to receive all of the recommended protocol-assigned therapy thereby resulting in improved survival. Furthermore, patients who had no/short delays had a significantly longer duration of maintenance therapy. These data indicate that treatment delays during consolidation do not worsen survival. Further studies are being done to better understand why patients with long delays had better overall survival.
Phase II Results of ECOG-ACRIN EA9152: A multicenter study of liposomal vincristine (L-VCR) or vincristine sulfate (VCR) and venetoclax (VEN) in relapsed or refractory acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL)
Palmisiano, Neil , Lee, Ju‐Whei , Paietta, Elisabeth , Park, Jae H. , Schaar, Dale , Webster, Jonathan , Luger, Selina M. , Litzow, Mark R. , Claxton, David F. , Podoltsev, Nikolai , Litzow, Mark R.

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 1577-1577

10.1182/blood-2025-1577 Get It

Abstract Background: Relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL) remain challenging to treat, particularly in older patients and those with a T-cell phenotype. Venetoclax (VEN), a selective BCL-2 inhibitor, has shown preclinical synergy with vincristine (VCR) in multiple preclinical ALL models. Following the previously reported establishment of the recommended Phase II dose (RP2D), we now report the results of the Phase II (Ph2) portion of EA9152 (VEN 600 mg daily with weekly L-VCR 2.25 mg/m² IV or VCR 1.5 mg/m2 IV capped at 2 mg), evaluating efficacy and safety in this high-risk population. Methods: This open-label, multicenter Phase II study enrolled adults (≥18 years) with R/R B- or T-cell ALL or LL. The phase II portion of this trial was a single-arm, open-label study evaluating the combination of VEN (600 mg po D1–28) with either L-VCR (2.25 mg/m² IV weekly x4) or vincristine sulfate (VCR) (1.4 mg/m² IV weekly x4). Following the market withdrawal of L-VCR in the United States in April 2022, no new patients were initiated on this formulation and patients already receiving L-VCR were transitioned to VCR at the start of their next treatment cycle or sooner if necessitated by drug availability. Prior VCR but not VEN exposure was permitted in Ph2. The primary endpoint was achievement of a complete response or complete response with incomplete count recovery CR + CRi rate by end of cycle 3. Secondary endpoints included measurable residual disease (MRD) response, progression free survival (PFS), overall survival (OS), and safety. The association of phenotype with response and time-to-event were evaluated using Fisher's exact test and the Cox proportional hazards model, respectively. Results: Twenty-one eligible patients were treated (B-cell ALL/LL: n=12; T-cell ALL/LL: n=9). The trial was terminated early after 22/56 patients were accrued on account of withdrawal of sponsor support. Median age was 50 years and 76.2% were male. Performance status was 0–1 in 85.7%. All patients had received prior chemotherapy; 47.6% had undergone prior transplant. Median number of treatment cycles was 1 (2 for B-cell, 1 for T-cell). By end of cycle 3, no patients in the B-cell cohort (0/12; 90% CI, 0.00–0.22) achieved CR or CRi, 8 had stable disease (SD). In the T-cell cohort, 1 of 9 patients (11.1%; 90% CI, 0.01–0.43) achieved CR, 1 achieved PR and 1 had SD. There was no statistically significant difference in CR + CRi rate between phenotypes (p=0.43). None of the patients achieved an MRD-negative CR/CRi by flow cytometry or molecular methods. At the time of this analysis, 16 of 21 patients had died. Median overall survival (OS) was 4.3 months (95% CI, 1.5–22.0) for B-cell and 10.2 months (95% CI, 2.0–16.4) for T-cell patients (HR 1.32, p=0.60). Median PFS was 2.9 months (95% CI, 1.7–3.7) for B-cell and 1.2 months (95% CI, 0.7–4.6) for T-cell cohorts (HR 2.18, p=0.18). Grade 3–5 treatment-related adverse events occurred in most patients. One T-cell patient experienced grade 5 respiratory failure. Among 16 patients enrolled under the revised protocol using VCR, only 1 experienced grade 3 peripheral motor neuropathy, and no peripheral sensory neuropathy was reported (combined AE rate 0.06; 90% CI, 0.00–0.26). Tumor lysis syndrome was not observed in this cohort. Conclusions: The combination of VEN at the established RP2D and L-VCR/VCR was feasible and had an acceptable safety profile in heavily pretreated patients with R/R ALL/LL. However, response rates, including CR/CRi and MRD negativity, were limited, particularly in the B-cell cohort. Median OS and PFS remain poor in both subtypes, highlighting the need for improved strategies in this high-risk population. Venetoclax, in combination with other chemotherapy regimens, has shown encouraging response rates warranting continued exploration of its benefit in ALL.
Clinical outcomes in adult AML with KMT2A rearrangements: A comparative analysis with R/R KMT2Ar and NPM1-mutated AML from the Mayo Clinic
Aldapt, Mahmood B, Fentie, Kin, Parker, Joseph D. , Foran, James M. , Gangat, Naseema , Kharfan‐Dabaja, Mohamed A. , Jiang, Jennifer , Fan, Yao‐Shan, Al‐Kali, Aref , Yi, Cecilia Y. Arana , Punwani, Nathan , Sproat, Lisa, Litzow, Mark, Patnaik, Mrinal M. , Parker, Joseph, Murthy, Hemant S. , Saliba, Antoine N. , Yi, Cecilia Arana , Badar, Talha

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 7030-7030

10.1182/blood-2025-7030 Get It

Abstract Background: KMT2A-rearranged acute myeloid leukemia (KMT2Ar AML) is characterized by chromosomal translocation involving KMT2A gene at 11q23, resulting in fusion with variety of partner genes. It is usually associated with poor outcomes, high risk of relapses and suboptimal responses to conventional therapies. While NPM1-mutated (mt) AML is considered favorable risk, they are equally dismal in relapse refractory (RR) setting. Menin inhibitors have emerged as a promising therapeutic strategy, particularly in RR AML patients (pts) with KMT2Ar and NPM1-mt genotypes. While revumenib, a menin inhibitor approved for managing RR KMT2Ar acute leukemia, no menin inhibitor is currently approved for NPM1-mt AML. In this study, we evaluated clinical outcomes of adults with KMT2Ar AML and performed a comparative analysis of pts with RR KMT2Ar and NPM1-mt AML using data from the Mayo Clinic. Methods: After screening 102 AML pts with reported KMT2A abnormalities, we identified 33 adults with confirmed KMT2Ar diagnosed between 2012 and 2024 for retrospective analysis. Clinical and molecular/cytogenetics data, induction type (intensive chemotherapy [IC] vs non-intensive chemotherapy [NIC]), response, transplant use, and survival outcomes were reviewed. A separate analysis was performed comparing 20 RR KMT2Ar AML pts with 20 propensity score matched RR NPM1-mt AML pts from a pool of 125 NPM1-mt RR pts. Results: The median age was 50 years (yrs) (range [R], 19.0-75.0), and 60.6% were < 60 yrs. Most cases were de novo AML (64%), and the most frequent translocation was t(6;11)(q27;q23)/MLLT4 (27%), followed by t(10;11)(p12;q23)/MLLT10 (21%), t(9;11)(p21.3;q23.3)/MLLT3 (15%), and t(11;19)(q23;p13.1)/ELL (12%). Other KMT2A fusion partners were rare and collectively accounted for the remaining cases. The median follow-up was 57 months (mo) (R, 7.0-109.0). The overall response rate (ORR) was 91%, and composite complete remission (CRc, , including CR, CRi, and CRh) was 73%. The CRc rates were comparable between IC and NIC (80% vs 62%, p=0.24). CRc were not significantly different by disease type (de novo [71.4%] vs secondary [sAML] [75%], p= 0.82) or KMT2A fusion partner gene (60% for t[9;11]/MLLT3 vs. 57.1% for t[10;11]/MLLT10 vs 55.6% for t[6;11]/MLLT4, p=0.069). Seventeen (52%) pts received an allogeneic stem cell transplantation (allo-HCT). The median overall survival (mOS ) for the entire cohort was 16 mo (R, 11.0-34.0). In subset analysis, IC compared to NIC was associated with significantly longer mOS (30 vs 11 mo, p=0.014). The mOS was also superior in pts <60 vs ≥60 yrs (32 vs 8 mo, p=0.005). Similarly, de novo cases had better mOS than sAML (22.0 vs 9.5 mo, p=0.052). Among KMT2Ar subtypes, t(6;11)/MLLT4 showed the longest mOS (54 mo [R, 30.0-not reached (NR)]), while t(9;11)/MLLT3 had the shortest (11.0 mo, [R 9-NR]), but differences were not statistically significant (p=0.32). The mOS was significantly longer among allo-HCT pts (30 vs 11 mo, p=0.005). Among 29 pts who experienced RR disease, the median relapse free survival (RFS) was 3 mo (R, 2.0-10.0). First salvage therapy yielded a CRc of 43.8% in 16 evaluable pts. When compared to a propensity matched cohort of 20 RR NPM1-mt AML pts, the CRc rates was 57.9% vs 50% in RR NPM1-mt and KMT2Ar AML (p= 0.68). The mRFS was not significantly different between RR KMT2Ar and NPM1-mt AML, (3 vs 4 mo, p=0.9). However, KMT2Ar pts had inferior mOS compared to NPM-mt AML (12 vs 65 mo, p=0.004). We further compared survival between NPM1-mt and KMT2Ar pts stratified by allo-HCT status. Among those who underwent allo-HCT, NPM1-mt pts had longer mOS (NR vs 22 mo, p=0.037). Among non-allo-HCT pts, mOS was numerically higher in NPM1-mt vs KMT2Ar (19 vs 8 mo, p=0.11). Conclusions: This single institusion cohort of adult AML with KMT2Ar underscores the biological and clinical heterogeneity of this high-risk group. IC was associated with a survival benefit, particularly among younger and fit patients. However, the outcomes following relapse remained poor, highlighting the urgent need for improved post-remission and salvage therapies. Comparative analysis with matched RR NPM1-mt AML pts revealed similarly dismal survival outcomes. Emerging data from single-arm studies of menin inhibitors in both frontline and RR settings among pts with NPM1-mt and KMT2Ar AML are encouraging and may represent a paradigm shift in treatment.
A randomized study of conventional chemotherapy +/- uproleselan in older adults with Acute Myeloid Leukemia eceiving intensive induction chemotherapy (Alliance A041701)
Uy, Geoffrey, Yin, Jun, Dinner, Shira, Jacoby, Meagan, Deangelo, Daniel, Liesveld, Jane, Kolitz, Jonathan, Asch, Adam, Odenike, Olatoyosi, Kour, Oudom, Skogen, Korrie, Byrd, Ken, Little, Richard, Gore, Steven, Carroll, Andrew, Mrózek, Krzysztof, Byrd, John, Eisfeld, Ann-Kathrin, Jaslowski, Anthony, Erba, Harry, Litzow, Mark, Stock, Wendy, Stone, Richard, Uy, Geoffrey, Yin, Jun, Dinner, Shira, Jacoby, Meagan, Deangelo, Daniel, Liesveld, Jane, Kolitz, Jonathan, Asch, Adam, Odenike, Olatoyosi, Kour, Oudom, Skogen, Korrie, Byrd, Ken, Little, Richard, Gore, Steven, Carroll, Andrew, Mrózek, Krzysztof, Byrd, John, Eisfeld, Ann-Kathrin, Jaslowski, Anthony, Erba, Harry, Litzow, Mark, Stock, Wendy, Stone, Richard

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 3415-3415

10.1182/blood-2025-3415 Get It

Abstract Background. Uproleselan (GMI-1271) is an antagonist of E-selectin, an adhesion molecule expressed on endothelial cells in the vascular niche of the bone marrow. Engagement of E-selectin by acute myeloid leukemia (AML) blasts, which express E-selectin ligand, activates cell survival pathways and promotes resistance to chemotherapy. In multiple preclinical AML tumor models, blockade of E-selectin with uproleselan enhanced the efficacy of chemotherapy. Methods. We conducted a phase (P) 2/3 study in which subjects age ≥ 60 years with untreated, FLT3 unmutated AML were randomized to receive conventional chemotherapy with or without uproleselan. Induction chemotherapy consisted of 7+3 (cytarabine + daunorubicin) +/- uproleselan with a second induction cycle with 5+2 +/- uproleselan administered for residual AML. Uproleselan 800 mg IV was administered as a single dose 24 hours before the first dose of chemotherapy and then every 12 hours until 48 hours after the completion of chemotherapy. Post-remission therapy consisted of up to 3 cycles intermediate-dose cytarabine 2 gm/m2 IV d1-5 +/- uproleselan. Allogeneic transplant was performed at the discretion of the treating physician. The primary endpoint was event-free survival (EFS) for P2 and overall survival (OS) for P3. Results. The study enrolled 267 patients between March 2019 and November 2021, with a median age of 66.9 years (IQR 63.8-69.9). 32% were classified as 2017 ELN intermediate risk, 41% as adverse risk, with 62 (29%) having complex karyotype / mutated TP53. The P2 analysis was to be performed when at least 191 events were observed. However, as the required events had not been observed > 5 years after study initiation and 3 years after completion of P2 enrollment, an independent statistician was consulted, and the analysis plan was amended to conduct the P2 EFS analysis in November 2024. With a median follow-up of 53.1 months, the EFS was not significantly different between the two arms (HR 0.90, 95% CI 0.70-1.23, P=0.58). As the study did not meet its P2 EFS endpoint, enrollment in the P3 was not initiated. There was no significant difference in OS between the 2 arms (HR 0.99, p=0.94) with a median OS in the uproleselan arm of 23.6 months (95% CI 15.1-35.4 mo) vs 19.8 months (14.6-36.3) for the control arm. The overall rate of CR/CRi after induction was 65% (CR: 60%) in the uproleselan arm versus 63% (CR: 55%) in the control. MRD results by either local or central assessment in patients achieving a CR/CRi were available for 129 patients with the MRDneg rate of 81 % (95% CI 69.5-89.9%) in the uproleselan arm vs 67% (54.3-78.4%) in the control arm (p=0.053), The 30-day mortality was 5.3% for uproleselan vs 8.1% in the control. Forty-eight (36%) patients in the uproleselan arm and 55 (40%) in the control arm underwent alloHCT, including 37 (27%) and 29 (22%) in CR1, respectively (p = 0.34). In patients undergoing alloHCT in CR1, those randomized to uproleselan and allografted in CR1 had an HR 0.71 (95% CI 0.34-1.47; P=0.35) compared to the control arm. Expression of E-selectin ligand on AML blasts was performed by flow cytometry, with subjects having an E-selectin ligand expression above the median having a trend towards worse median OS 16.2 (95% CI 11.4-24.3) vs 32.2 (15.9-57.8) months, but was not affected by treatment arm. In both univariate and multivariate analyses, WBC at baseline, ELN genetic risk group, and TP53/complex karyotype were found to be associated with EFS. A subgroup analysis identified an improvement in EFS favoring uproleselan in patients with mutated ASXL1 (HR 0.25, 95% CI 0.08-0.78, p<0.017). Conclusions. Although the addition of uproleselan to intensive chemotherapy was associated with a higher rate of MRDneg CR/CRi in older adults with AML, uproleselan failed to improve EFS or OS and did not overcome the adverse outcomes associated with higher E-selectin expression on AML blasts. The median OS of 20-24 months with an overall 3-year OS of almost 40% for patients treated on this study exceeds previous CALGB / US Cooperative Group studies (median OS ~12 months, 3-year OS ~20%) and continues to support a role for intensive chemotherapy in the management of older adults with AML. Furthermore, this study suggests a potential benefit for uproleselan in patients harboring ASXL1 mutations, which may warrant further investigation. ClinicalTrials.gov Identifier: NCT03701308
Identifying fusions in AML/MDS: An experience from first 400 patients enrolled into myelomatch
Qu, Xiaoyu , Chen, Xueyan , Wood, Brent, Zák, A, Narava, Srikrishna K. , Chang, Ting‐Chia , Baldivieso, Celso, Kamath, M. Panduranga , Ramineni, Bhanumati , Litzow, Mark R. , Doroshow, James H. , Harris, Lyndsay N. , Radich, Jerald P. , Little, Richard F. , Jiwani, Shahanawaz S. , Fang, Min, Yeung, Cecilia C.S. , Zak, Andrea, Kamath, Megha, Othus, Megan , Erba, Harry Paul , Litzow, Mark R.

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 340-340

10.1182/blood-2025-340 Get It

Abstract Introduction: MyeloMATCH (mM), is an National Cancer Institute (NCI)-sponsored precision medicine initiative for newly diagnosed AML/MDS. It consists of an initial screening study (Master Screening and Reassessment Protocol, or MSRP) that involves centralized testing of bone marrow/whole blood, leading to assignment into several genetically driven treatment subprotocols within the mM portfolio. MSRP employs karyotype, 8-15 probe fluorescence in situ hybridization (FISH) and NCI-myeloid (NMAv2) assays to determine ploidy, translocations and mutational status needed for accurate disease subclassification, risk stratification as well as for theragnostic determination. NMAv2, a rapid next generation sequencing assay (TAT<48 hrs), interrogates 45 DNA and 35 RNA fusion driver genes to report 1661 hotspot DNA mutations and 779 targeted RNA fusions, including all relevant fusions in AML except Inv3/t(3;3)/MECOM rearrangement (Yeung et al, 2025). The initial mM MSRP workflow relied on karyotype and FISH assay results to identify fusion positive AML/MDS as per the current testing guidelines/ recommendations as well as to abide by the FDA's requirements under the investigational device exemption (IDE). Here we present concordance analysis between karyotype, FISH and NMAv2 assay to identify relevant fusions in AML/MDS. Methods: First 400 participants enrolled in the mM MSRP were included in this analysis. We examined the results from karyotype analysis analyzing 20 metaphase cells, 8-15 probe FISH analyzing 500 nuclei per probe, and NMAv2 curating fusion read counts greater than 100, performed at the mM labs to determine the prevalence of fusions in this cohort. Concordance analysis was performed to determine clinical utility of the NMAv2 assay to report relevant fusions at the time of initial diagnosis. The concordance analysis excluded biomarkers including Inv3/t(3;3)/MECOM rearrangement, KMT2A-PTD and other rare fusions that are beyond the scope of detection by NMAv2 and/or FISH assay. Results: Of the 400 patients analyzed in this cohort (median age 64, [range 20-95]; 43% female; 15.5% non-white; 9.5% Hispanic), translocations/fusions were reported in 67, 73 and 95 patients by karyotype, 8-15 probe FISH and NMAv2, respectively. The karyotypic analysis reported inv(16)/t(16;16) [15], t(11q23) [13], t(9;22) [10], inv3/t(3;3) [9], t(8;21) [6], t(15;17) [5], t(6;9) [4], t(21q22) [3], t(9q34) [1] and t(10;11) [1]. The FISH reported inv(16)/t(16;16) CBFB::MYH11 [15], t(11q23) KMT2A rearrangement [14], t(9;22) BCR::ABL1[10], inv3/t(3;3) MECOM rearrangement [10], t(8;21) RUNX1::RUNX1T1 [7], t(15;17) PML::RARA [5], t(6;9) DEK::NUP214 [5], t(21q22) RUNX1 rearrangement [3], t(11p15.4) NUP98 rearrangement [3], and t(9q34) ABL1 rearrangement [1]. The NMAv2 reported KMT2A-PTD [26], CBFB::MYH11 [15], KMT2A fusion [14], BCR::ABL1[12], RUNX1::RUNX1T1 [8], PML::RARA [5], DEK::NUP214 [5], RUNX1 fusion [4], NUP98 fusion[3], t(9q34) ABL1 fusion [1], PICALM::MLLT10 [1] and ETV6::MECOM [1]. The concordance analysis between NMAv2 and karyotype assay demonstrated positive percent agreement(PPA) of 100%, negative percent agreement(NPA) of 96.81% and overall agreement (OA) of 97.25% when using karyotype as reference. The concordance analysis between NMAv2 and FISH assay demonstrated PPA of 100%, NPA of 98.81% and OA of 99% when using FISH as reference. Of the 12 cases with discrepant results, 7 were due to presence of cryptic translocations missed by karyotype assay, 3 had suboptimal specimen submitted for karyotype/FISH analysis, 1 had false positive BCR::ABL1 fusion reported by NMAv2 due to low level contamination and 1 had minor subclonal population of leukemic blast with BCR::ABL1 fusion detected only by NMAv2. Conclusion: NMAv2 shows high concordance with karyotype and FISH assays which are the most commonly utilized assays to identify fusions/translocations in AML/MDS. NMAv2 is a faster, relatively cheaper and sample conserving method to identify fusions and is less prone to false negative results than karyotype/FISH assay from suboptimal specimen acquisition and testing. Based on the results above, mM MSRP workflow has been amended with FDA concurrence such that a combination of NMAv2, karyotype and MECOM breakapart FISH assay will be used to identify relevant fusion variants in all patients enrolled in mM, whereas additional specific FISH assay will be limited to cases where discrepant results between karyotype and NMAv2 are reported.
Prospective study of patient-reported depression, and cognitive and functional impairment, and impact on survival and induction mortality in fit adults age ≥60 years receiving intensive chemotherapy (IC) for Acute Myeloid Leukemia (AML): Prospective geriat
Foran, James M. , Luger, Selina M. , Sun, Zhuoxin , Rowe, Jacob M. , Paietta, Elisabeth , Racevskis, Janis, Altman, Jessica K. , Al‐Kali, Aref , Zheng, Hong , Pratz, Keith W. , O’Dwyer, Kristen M. , Broun, E. Randolph, Powell, Bayard, Litzow, Mark, Tallman, Martin S. , Chen, Li , Klepin, Heidi D. , Lai, Catherine , Claxton, David F. , Lazarus, Hillard M. , Arber, Daniel A. , Garrett-Bakelman, Francine E. , Zhang, Yanming , O'Dwyer, Kristin , Godwin, John E. , Ofran, Yishai , Dotan, Efrat , Wagner, Lynne I.

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 882-882

10.1182/blood-2025-882 Get It

Abstract Background We performed a prospective study evaluating a baseline GA battery and clinical outcomes in fit older adults (age ≥60 years) with AML and normal cardiac and renal function in the recent E-A NCTN E2906 phase 3 study. A patient-reported outcomes (PRO) assessment of Depression, Activities of Daily Living (ADL), Cognitive Function, Social Support (SS) domains, and comorbidity was performed at study registration to evaluate the prevalence of vulnerabilities and their impact on overall survival (OS) and 30-day induction mortality rates (IM) in this cohort selected for fitness to receive IC. Methods E2906 study design and results have been presented previously [n=727, age ≥60 years, randomized 1:1 to ‘standard 7&3‘ & high dose cytarabine (Arm A) vs. single agent clofarabine (CLO, Arm B), as remission induction (Step 1) and consolidation (Step 2)]. There was no difference in composite complete remission (CCR, 50%) or IM (8.5%), and CLO was inferior for OS. A baseline GA was a key secondary protocol objective, offered to all patients, and n=532 (73%) participated. We assessed Geriatric Depression Scale (GDS, none vs. any depressive symptoms, n=524); cognitive screen using Mini-Mental Exam Section (MMES, score 8/8 vs. <8, n=516); ADL & Instrumental ADL (iADL), (need for assistances vs. not n=526); a Medical Outcomes Study SS Survey (MOS-SS, measured as per unit increase, n=527); a Comorbidity survey ( ≤4 vs. ≥5 patient-reported comorbidities, n=530), patient-reported prescription medications use (PM, 0-3 vs. ≥4, n=519); and a survey of Sexual Desire (n=491) and Sexual Activity (n=477) within 4 weeks of AML diagnosis. Association of GA domains with OS, IM, and achievement of CCR was evaluated using the Chi-squared, Fisher's exact, and Wilcoxon rank sum test. Survival analysis was performed using the Cox proportional hazards models, adjusted for treatment arm. All p-values are 2-sided. Results The median age among those participating in GA battery was 67 yrs (range 60-85), including 38% age ≥70. There were 42% females, and ECOG performance status was 0 (28%), 1 (54%), 2 (16%), or 3 (2%). Central Cytogenetic review was classified (ELN2017) as Favorable (3%), Intermediate (66%), and Adverse (31%) risk. There was a notable rate of GA scores outside ‘normal’ clinical cutoff, including Depression (GDS 31%), cognitive and functional impairment [MMSE (37%), ADL (25%) and iADL (32%)], ≥5 Comorbidities (23%), and ≥4 PM's (44%). 81% & 76%, respectively, reported no sexual activity and low/none sexual desire. MOS-SS tended to be high in this cohort [mean (SD) score 87 (17)]. We observed a significant association of GA domains with OS & IM. For OS, absence of depressive symptoms [GDS, Hazard Ratio (HR) 0.79, 95% confidence Intervals (CI) 0.64-0.97, p=0.025)], MMES 8/8 (HR 0.78, 95%CI 0.64-0.96, p=0.016), requiring no assistance with ADLs (HR 0.65, 95%CI 0.52-0.82, p<0.001) and iADLs (HR 0.69, 95%CI 0.57-0.85, p<0.001), and ≤4 Comorbidities (HR 0.68, 95%CI 0.54-0.84, p=0.001) were significant for superior OS; use of ≥4 PM's was associated with inferior OS (HR 1.32, 95%CI 1.09-1.61, p=0.005). There was no association of sexual activity/desire, BMI ≥30 kg/m2, or MOS-SS with OS. IM was significantly higher among those with any depression symptoms (GDS, p=0.005), any ADL (p=0.010) or iADL (p=0.013) impairment, ≥5 comorbidities (p=0.037) and ≥4 PM's (p=0.001); there was no association with MOS-SS or MMES. There was no significant association of GA scores with cytogenetic risk group or with CCR rates. Only ADL independence (p=0.048), and possibly Comorbidity ≤4 (p=0.071), were associated with proceeding to Step 2. Conclusions In this large prospective cohort of fit older adults with AML selected to receive IC, we observed high rates of PRO-assessed GA vulnerability, which was significantly associated with inferior OS and higher IM rates, and (for ADL impairment) lower rates of proceeding to consolidation therapy. This suggests that functional and cognitive impairments are prevalent and can significantly impact outcome even in fit older adults. Despite potential long-term OS advantages of IC previously observed in E2906, efforts to systematically recognize those at higher risk based on GA PROs are needed to help identify patients who may be more appropriate for study of lower intensity treatment options to mitigate impact on IM and OS. SImilarly we plan to evaluate the potential benefit of GA-driven supportive care to improve patients' outcomes.
Time from AML diagnosis to HCT and pre-HCT FLT3 inhibition impact pre-transplant MRD and benefit from post-HCT gilteritinib
Levis, Mark J., Logan, Brent R. , Jones, Richard J. , Singh, Anurag K. , Litzow, Mark R. , Papadopoulos, Esperanza B. , Perl, Alexander E. , Soiffer, Robert J. , Üstün, Celalettin , Oshima, Masumi Ueda, Vasu, Sumithira, Solh, Melhem , Mishra, Asmita , Muffly, Lori , Stelljes, Matthias , Onozawa, Masahiro , Thomson, Kirsty , Chen, Caroline , Hasabou, Nahla, Rosales, Mathew, Gill, Stanley C. , Nuthethi, Rishita, King, Denise , Mendizabal, Adam , Horowitz, Mary, Chen, Yi‐Bin , Muffly, Lori , Levis, Mark J. , Hamadani, Mehdi , Litzow, Mark R. , Wingard, John R. , Oshima, Masumi Ueda, Uy, Geoffrey L. , Waller, Edmund K. , Vasu, Sumithira , Kim, Heeje, Najima, Yuho , Rosales, Mathew, Hill, Jason E. , King, Denise, Devine, Steven M.

Mayo Clinic

Blood | December 4, 2025 | Volume: 146 | Issue: Supplement 1 | Pages: 1058-1058

10.1182/blood-2025-1058 Get It

Abstract Aims BMT CTN 1506 (“MORPHO”) was a global phase 3 study of post-hematopoietic cell transplantation (HCT) maintenance with gilteritinib versus placebo for patients with FLT3-ITD-mutated AML in CR1. The study did not meet its primary endpoint of improved relapse-free survival (RFS) for post-HCT gilteritinib, but subgroup analysis indicated a benefit for participants with pre-HCT measurable residual disease (MRD). Subgroup analysis also indicated a statistically significant benefit of post-HCT gilteritinib for participants in North America, but no benefit for those in Europe or Asia. RFS for the control arms in Europe and Asia was higher than anticipated, suggesting that participants with different disease biology may have accrued to the study in these different geographic regions. In the primary analysis of the study, pre-HCT FLT3 inhibitor use and MRD across the entire study population were both found to have impacted outcomes. Time from diagnosis to HCT, a reflection of local practice patterns, is also known to impact outcomes for FLT3-ITD AML. We hypothesized that local practice patterns of pre-HCT FLT3 inhibitor use and time from AML diagnosis to HCT could have influenced the disease biology of study pts at the time of enrollment. This would be predicted to result in pre-HCT MRD levels and could provide an explanation for the regional differences observed in the study outcome. Methods We conducted a post-hoc analysis of the data focusing on days from AML diagnosis to HCT, pre-HCT FLT3 inhibitor use, and FLT3-ITD MRD assessed by a high-sensitivity assay. Eligibility requirements included FLT3-ITD-mutated AML in first remission after intensive chemotherapy and HCT occurring within 12 months of achieving remission. Patients refractory to induction therapy, or those with a history of relapse, were ineligible. Results Accrual took place in 16 different countries, with 5 countries accounting for 79.7% of the total accrual: USA 42.7%; Japan 15.7%; Korea 8.4%; UK 6.7%; Germany 6.2%; other countries 20.2%. In two countries, USA and Germany (48.9% of total enrollment), participants underwent HCT a median of 119 days after AML diagnosis, and 90.2% were treated with a FLT3 inhibitor pre-HCT. In contrast, in Japan, Korea, the UK and the other 11 countries all combined, participants underwent HCT a median of 152.5 days after AML diagnosis, and only 30.8% received any FLT3 inhibitor pre-HCT. Amongst all participants, those transplanted < 120 days from AML diagnosis and/or those treated with FLT3 inhibition pre-HCT were more likely to have improved RFS from post-HCT gilteritinib. RFS was improved with post-HCT gilteritinib in the US and Germany (HR 0.397; CI 0.220-0.718), whereas no benefit was evident in all other countries combined (HR 1.184; CI 0.685-2.048). Pre-HCT MRD levels were significantly higher (P = 0.011) in participants transplanted within 120 days from diagnosis as well as in those treated with a FLT3 inhibitor pre-HCT and also transplanted within 120 days (P = 0.019). Pre-HCT MRD was dependent on both FLT3 inhibitor use and time to HCT, as participants treated with successive courses of chemotherapy + FLT3 inhibition had successively lower MRD by the time of HCT. Conclusions The time from AML diagnosis to HCT and FLT3 inhibitor use pre-HCT both appeared to impact MRD levels immediately prior to HCT, and geographic differences in these two practice patterns likely accounted for the regional differences in benefit from post-HCT gilteritinib observed in BMT CTN 1506. Successive courses of chemotherapy without FLT3 inhibition appears to have selected a more favorable risk (e.g., MRD-lower) population for enrollment. Successive courses of chemotherapy combined with FLT3 inhibition progressively eradicated MRD, such that a majority of participants undergoing HCT after 3 or 4 courses were MRD negative and therefore unlikely to benefit from post-HCT gilteritinib. These findings have implications for clinical practice. Increasing the number of courses of chemotherapy combined with FLT3 inhibition before HCT may lower MRD sufficiently to eliminate the need for post-HCT inhibition for some patients but, alternatively, the additional delay could increase the risk of pre-HCT relapse, preventing patients from receiving HCT in first remission.