Alkhateeb, Hassan B.

ABSTRACT Patients with newly diagnosed acute myeloid leukemia (ND‐AML) derive variable survival benefit from venetoclax + hypomethylating agent (Ven‐HMA) therapy. The primary objective in the current study was to develop genetic risk models that are predictive of survival and are applicable at the time of diagnosis and after establishing treatment response. Among 400 ND‐AML patients treated with Ven‐HMA at the Mayo Clinic, 247 (62%) achieved complete remission with (CR) or without (CRi) count recovery. Multivariable analysis–derived hazard ratios (HR), including 1.8 for European LeukemiaNet (ELN) adverse karyotype, 4.7 for KMT2Ar , 1.7 for TP53 MUT , 2.6 for KRAS MUT , and 2.1 for IDH2 WT were applied to develop an HR‐weighted risk model: low, intermediate, and high; respective median survival censored for allogeneic stem cell transplant (ASCT) (3‐year survival) were “not reached” (67%), 19.1 (33%), and 7.1 months (0%). In patients achieving CR/CRi, adverse karyotype, KMT2Ar , KRAS MUT , IDH2 WT predicted inferior survival, allowing for a complementary response‐stratified risk model. The model was externally validated and was shown to be superior to the ELN 2024 risk model (AIC 179 vs. 195 and AUC 0.77 vs. 0.69). Survival was inferior with failure to achieve CR/CRi or not receiving ASCT; 3‐year survival for high‐risk with or without ASCT was 42% versus 0% ( p < 0.01); intermediate 72% versus 43% ( p = 0.06); and low‐risk 88% versus 78% ( p = 0.53). The Mayo genetic risk models offer pre‐treatment and response‐based prognostic tools for ND‐AML treated with Ven‐HMA. The current study underscores the prognostically indispensable role of achieving CR/CRi and ASCT.

Introduction: Post-transplant cyclophosphamide (PTCy) has emerged as the new standard of care for graft-versus-host disease (GVHD) prophylaxis following reduced-intensity conditioning (RIC) allogeneic stem cell transplant (alloSCT). The BMT CTN 1703 phase III trial demonstrated superior GVHD/relapse or progression-free survival (GRFS) in patients receiving PTCy, without affecting relapse risk. The primary objective of this study was to compare the risk of relapse in high-risk myeloid neoplasms post RIC/Nonmyeloablative (NMA) transplant using PTCy vs Tacrolimus/Methotrexate (TAC/MTX) as GVHD prophylaxis (PPX). Methods: We retrospectively reviewed patients with high-risk myeloid neoplasms following RIC/NMA alloSCT who received PTCy or TAC/MTX for GVHD PPX between Jan 2018 and June 2023. Criteria for high-risk myeloid neoplasms included acute myeloid leukemia (AML) with ≥1 of the following (complex or monosomal karyotype, TP53, WT1, FLT3 ITD+/NPM1-, active disease, MRD+, secondary AML), Myelodysplastic syndrome (MDS) with ≥1 of the following (complex karyotype, monosomal karyotype, TP53, RAS pathway mutation, marrow blast of 10% or more) or chronic myelomonocytic leukemia (CMML). Kaplan-Meier and log-rank tests were used to estimate overall survival (OS) and disease-free survival (DFS). Non-relapse mortality (NRM) and relapse incidence (RI) were calculated using competing risk analysis. Factors with P&lt;0.10 in univariate analysis were included in multivariate analysis Results: Out of 552 alloSCTs, 108 (19.5%) patients met the inclusion criteria. Seventy-two (66.6%) received TAC/MTX, and 36 (33.3%) received PTCy. The median follow-up time was 26 months (range 3-68). The median age at transplant was 65 years (range 62-69) with age comparable between the two groups (p=0.6). Haploidentical transplant accounted for 33.3% of PTCy, while the remainder had matched related or matched unrelated transplant (MRD/MUD). Compared to TAC/MTX group, the PTCy group had more frequent NRAS mutation (19.4% vs 8.3%, p=0.094), but fewer patients with hematopoietic cell transplantation-specific comorbidity index (HCT-CI) ≥ 3(41.7% vs 61.1%, p=0.056). AML MRD+ was more prevalent in the PTCy group (22.2% vs 8.3%, p=0.098). The two groups were otherwise well-balanced in terms of disease distribution, disease risk index, TP53 mutation, and complex monosomal karyotype (CK and MK). The 1-yr OS, DFS, and GRFS for PTCy vs TAC/MTX were 78.7% vs 72.8% (p=0.9), 53.6% vs 67.9% (p=0.2), 38% vs 40%, (p=0.4), respectively. The 1-yr cumulative incidence of relapse (CIR) was higher in PTCy compared to TAC/MTX (37.6% vs 11.1%, p=0.01). Both haploidentical and MRD/MUD in the PTCy group had similar 1-yr RI (34.7 vs 38.3% p=0.7). Limiting the analysis to MRD/MUD, the PTCy group had a higher risk of relapse compared to TAC/MTX (34.7% vs 10.2%, P=0.007). Sub-analysis showed a higher 1-yr-CIR in the PTCy cohort for secondary AML (40% vs 0.0%, p=0.01), TP53 mutation (44.4% vs 18.1%, p=0.02), CK/MK (71.4% vs 22.2%, P=0.008), and chromosome 17 abnormality (60% vs 10%, P=0.001), compared to TAC/MTX. Despite of the increased CIR in the PTCy group, only patients with chromosome 17 abnormality receiving PTCy had an inferior DFS compared to TAC/MTX (median 5 vs. 14 months, p=0.008). In multivariate analysis for 1-yr CIR that included TP53, chromatin modifiers mutations, complex karyotype, high/very high DRI, and PTCy, both PTCy (HR 4.56, 95% CI 1.1-18.07, p=0.031) and high/very high DRI (HR 12.745, 95% CI 1.5-103.4, p=0.017) were independently predictive of post-transplant relapse. However, these factors were not significantly associated with 1-year OS. Conclusion:In patients with high-risk MN following RIC/NMA alloSCT, those receiving PTCy as GVHD PPX had a higher risk of relapse compared to TAC/MTX, irrespective of the donor source. Notably, an inferior DFS was observed only in patients with chromosome 17 abnormality who received PTCy. Despite of the increased relapse risk in the PTCy group, OS, DFS, and GRFS were comparable to TAC/MTX, likely due to higher risk of GVHD and NRM in the latter group.

Background: There is an increased risk of second primary malignancies including second hematological malignancies (SHM) in multiple myeloma (MM) patients undergoing autologous stem cell transplant (auto-SCT) followed by lenalidomide maintenance. We analyzed the characteristics and outcomes of patients who developed SHM after an auto- SCT for MM. Methods: A retrospective study of all MM patients who underwent auto- SCT at Mayo Clinic, Rochester between January 1, 1990, and 31 August 2023 and later developed SHM. Demographic, clinical and pathologic data were collected retrospectively. Overall survival (OS) was calculated from the date of auto-SCT to the date of last follow up. Statistical analyses were performed using GraphPad prism 9.0. Chi-square test was used to calculate the difference between categorical variables. Kaplan Meier method and log rank test were used to estimate OS. Results: Among 3513 patients who underwent at least 1 auto-SCT, 104 (2.9%) developed a SHM at a median follow up of 59 (range, 0.2-265) months. Patients who developed SHM, more frequently received pretransplant alkylating agents (37.5 vs 24.2 %, odds ratio [OR], 1.87; P=0.003) and topoisomerase II inhibitors (anthracyclines/etoposide) (17.3% vs 10.4%, OR [1.79]; P=0.03) compared to a control group of MM patients without SHM. Further, exposure to lenalidomide (77.8% vs 57.6%, OR[2.59]; P &lt;0.0001) and radiation therapy (32.6% vs 23.1%, [1.54]; P=0.04) were more often seen in the SHM cohort compared to control group. Among the 381 patients who underwent &gt; 1 auto- SCT, 3.1% developed SHM. Therapy related myeloid neoplasms (t-MN) accounted for 90.3% of cases [n=94; t-myelodysplastic syndrome (t-MDS=64), t-acute myeloid leukemia (t-AML=12), t-MDS transformed to AML(n=16), chronic myeloid leukemia (n=1), MDS/myeloproliferative neoplasm overlap syndrome (n=1)]. Eight patients (7.6%) developed therapy related B- cell acute lymphoblastic leukemia (t-ALL); Philadelphia (Ph) negative ALL (n=7) and Ph- like ALL (n=1). One patient each developed mixed phenotype acute leukemia and acute leukemia, not otherwise specified. Sixty patients (57.6%) were males and the median age at diagnosis of SHM was 70 (range, 43-84) years. The median time from auto-SCT to diagnosis of SHM was 58.5 (range, 7-236) months. In a multivariate analysis, receiving an alkylating agent (hazard ratio [95% confidence interval]: 2.51 [1.54 to 4.01]; P = 0.0002) and/or topoisomerase II inhibitor as induction for MM (3.12 [1.59 to 5.88]; P = 0.0006), exposure to lenalidomide (7.08 [3.92 to 13.50]; P = &lt;0.0001) and radiation therapy (1.60 [1.02 to 2.44]; P = 0.03) were independent predictors of developing SHM. At diagnosis, 57% (n=37) of t-MDS and 71% (n=20) with t-AML had high risk disease per R-IPSS and 2022 European Leukemia Net respectively. Clonal abnormality in chromosome 5 and/or 7 was present in 45% (n=42) of patients. Complex and monosomal karyotype was seen in 32% (n=30) with t-MN. The most frequently mutated genes based on next generation sequencing data included TP53 (n=33), DNMT3A (n=9), RUNX1 (n=5), TET2 (n=4) and CEBPA (n=4). In the t-MDS/AML cohort, 3 patients (3.1%) underwent second auto-SCT and 9 (9.5%) received allogenic SCT (allo-SCT) for SHM. After a median follow-up of 27.2 months, the median OS from t-MDS/AML diagnosis was 8.04 months (95%CI, 6.1-11.0 months) and there was no difference in median OS for allo-SCT recipients versus nonrecipients (9.1 vs 6.8 months, P =0.19). In the t-ALL (n=8) cohort, all of them received lenalidomide based induction and five received lenalidomide maintenance. Most of the t-ALL patients had adverse risk cytogenetics [IKZF1 deletion (n=2), complex karyotype (n=2), TP53 mutation (n=1) and P2RY8-CRLF2 fusion (n=1)]. Three patients with t-ALL underwent allo-SCT and the median OS for allo-SCT recipients versus non recipients were 8.3 vs 7.9 months respectively, P=0.50. Among patients with SHM, 92.3% (n = 96) have died with SHM (72%) being the most common cause of death. MM patients who developed SHM had an inferior OS when compared to those without SHM (median OS, 75 vs 90 months, P =0.006). Conclusion: SHM following auto-SCT tends to have aggressive disease biology with poor outcomes. Short term follow up underestimates the risk of SHM and the higher incidence noted in our study may be due to longer follow up. As the OS in MM patients continues to improve, SHM remains an important challenge in improving long term outcomes.

Introduction Chronic myelomonocytic leukemia (CMML) is associated with a 15-30% risk for blast transformation (BT) over 3-5 years. Post-BT survival remains dismal with a median overall survival (mOS) of ~6 months (mo), even with intensive therapies. Although genetic drivers are identified in &gt;40% of BT-CMML cases (Carr, 2021), mechanisms of BT remain to be elucidated. This multicenter study examines risk factors for BT in CMML and predictors of post-BT survival. Methods CMML patients at Mayo Clinic (n = 400, 47%) and MD Anderson Cancer Center (n = 449, 53%) were included with IRB approval. Analyses used clinical and molecular data at diagnosis or first referral in chronic phase (CP) and again at BT. Categorical variables were compared by Chi squared and continuous by Mann-Whitney U or Kruskal-Wallis tests. Multivariate analyses used Cox proportional hazards models with binarization via receiver operator curves. Kaplan-Meier analyses were censored at hematopoietic cell transplantation (HCT). P &lt; 0.05 was considered significant. Calculations used BlueSky (v10.3.1) or Prism (v10.2.3). Results Of 849 CMML patients (median age 71 years, 32% female, 90% white) included in the study, 133 (16%) underwent BT. In comparison to CP-CMML without BT, those with BT were more likely (p &lt; 0.05) to have had higher WBC counts (15.1 vs 11.4 x109/L), higher absolute monocyte counts (2.9 vs 2.2 x109/L), lower platelet counts (84 vs 102 x109/L), have circulating immature myeloid cells (52% vs 37%), and be classified as myeloproliferative (MP)-CMML (58% vs 44%) or CMML-2 (33% vs 17%) at diagnosis/first referral in CP. More mutations were detected in BT-CMML than in CP-CMML (mean 3.2 vs 2.8, p = 0.002). Mutations in RAS (NRAS, KRAS, BRAF, CBL, PTPN11; 51% vs 40%, p = 0.02) and signaling (CSF3R, FLT3, JAK2, SH2B3; 15% vs 7%, p = 0.004) pathway genes were more frequent in BT-CMML. Conversely, there were fewer BT-CMML patients with the favorable ASXL1WT/TET2MT genotype compared to CP-CMML (22% vs 33%, p = 0.004). Multivariate analysis identified MP-CMML (hazard ratio [HR] 1.5, p = 0.04), CMML-2 (HR 2.4, p &lt; 0.001), and the presence of ≥4 somatic gene mutations (HR 1.8, p = 0.002) as risk factors for BT whereas the ASXL1WT/TET2MTgenotype was protective (HR 0.45, p = 0.002). The ASXL1WT/TET2MT genotype was also protective in the MP-CMML (HR 0.49, p = 0.04) and RAS-mutated (HR 0.35, p = 0.005) subgroups. Amongst BT-CMML cases, the median time to BT was 10 mo from diagnosis/referral. Compared to their CP assessment, patients in an overlapping Mayo Clinic BT-CMML cohort (n = 156, median age 69 years, 35% female) were more likely to have NPM1 (24% vs 3%, p &lt; 0.001) and IDH2 (14% vs 1%, p = 0.01) mutations at BT. Amongst cases with paired molecular evaluations (n = 44), 7 (16%) acquired new mutations, including FLT3-ITD (n = 2) and NPM1 (n = 2). Conversely, 6 (14%) lost mutations, including TET2 (n = 3), SRSF2 (n = 2), CBL, NRAS, or PTPN11 (n = 1 each). There were no differences in variant allele fractions in driver genes present at CP and BT. Abnormal karyotypes were more prevalent at BT than in CP (60% vs 34%, p &lt; 0.001), and 26 (25%) patients with a normal karyotype in CP acquired structural (65%) and/or numerical (69%) changes at BT, including 6 (23%) that acquired a complex karyotype. Acute myeloid leukemia defining translocations were seen in 4 (4%) cases: 2 with t(8;21) and 1 each with inv(3) and t(10;11)(KMT2A::TET1). After considering mutation and karyotype changes, only bone marrow blasts ≥30% (HR 1.7, p = 0.04) were independently prognostic for OS after BT (mOS 4 mo). Compared to supportive care (n = 50, mOS 1.3 mo), OS was improved by hypomethylating agents (HMA, n = 14, mOS 16 mo, HR 0.3, p &lt; 0.001) or induction chemotherapy (n = 56, mOS 8 mo, HR 0.3, p &lt; 0.001), but not by HMA + venetoclax (n = 11, mOS 6 mo, HR 0.7, p = 0.4). Allogeneic HCT (n = 28) improved mOS to 46 vs 3 mo (p &lt; 0.001). Amongst 4 patients with paired whole genome sequencing before and after BT, 3 had increased copy number alterations (including 2 with loss of heterozygosity, 2 with gains, and 3 with deletions) while the 4th acquired novel likely pathogenic somatic mutations (MUC4, BAX, WNK2). Conclusions Survival in CMML after BT remains exceptionally poor. In this multicenter cohort, MP-CMML, CMML-2, and the presence of ≥4 somatic gene mutations were identified as risk factors for BT, with the ASXL1WT/TET2MT genotype being protective. Following BT, bone marrow blast burden ≥30% was an independent adverse predictor of survival.

Background: TP53-mutated (TP53mut) myeloid neoplasms (MN) have particularly poor survival. Discrepancies in defining TP53mut MN have impact on diagnostic work up, therapeutic decisions, and clinical trial enrolment. Methods: MN cases harboring TP53mut (variant allele frequency, VAF ≥2%) were classified based on bone marrow (BM) and peripheral blood (PB) blast % using the 4th revision of the WHO classification (WHO-4R). Biallelic loss was defined as (i) ≥2 mutations each with VAF ≥2%; (ii) single TP53mut VAF ≥2% plus 17p loss detected on karyotype, FISH, or SNP; or (iii) single TP53mut VAF ≥50%, whereas monoallelic loss was defined as single TP53mut VAF &lt;50% without 17p loss. Primary endpoint was overall survival (OS) from diagnosis. Conditional Inference Trees (CIT) analysis was used to determine the true effect of a predictor. Results: We identified 580 cases including WHO-4R defined acute myeloid leukemia (AML, BM/PB blasts ≥20%, n=219, 37.8%), myelodysplastic syndrome (MDS) with excess blasts-2 (EB-2, BM 10-19% or PB 5%-19%, n=92, 15.9%), MDS with excess blasts-1 (EB-1, BM 5-9% or PB 2-4%, n=75, 12.9%), and the remaining were MDS with low blasts (-LB, BM &lt;5% and PB ≤1%, n=194, 33.4%). Of the 578 cases evaluable for allelic status, 437 (75.6%) and 141 (24.4%) had biallelic and monoallelic TP53 loss, respectively. Higher frequency of biallelic loss was observed with increasing blasts. 63.2%, 73.3%, 78% and 86.3% of cases with MDS-LB, MDS-EB1, MDS-EB2, and AML had bi-allelic TP53 loss (P&lt;0.0001). In a multivariable analysis, WHO-4R categories, VAF ≥10%, and biallelic loss were independent predictors of poor survival. CIT analysis further stratified the cohort into 4 groups with distinct survival: (1) MDS-LB (n=194, 33.4%); (2) MDS-EB1/EB2 and AML with VAF &lt;10% (n=38, 6.6%); (3) MDS-EB1/EB2 with VAF ≥10% (n=149, 25.7%); and (4) AML with VAF ≥10% (n=199, 34.3%). MDS-LB cases could be further stratified based on allelic status and complex karyotype (CK): OS was poor for cases with biallelic TP53 loss and monoallelic TP53mut with CK compared to monoallelic TP53mut without CK, who had the most favorable survival (12.7 vs. 13 vs. 34.8 months, P&lt;0.0001).MDS-EB1/EB2/AML with VAF&lt;10% could also be stratified by CK: MDS-EB1/EB2/AML with VAF&lt;10% cases without CK had the favorable survival compared to their counterparts with CK and MDS-EB1/EB2 with VAF ≥10% cases (26.2 vs. 5.6 vs. 6.3 months, P=0.003).MDS-EB1/EB2 with VAF ≥10% was a homogenous subgroup: Biological characteristics including the proportion of cases with biallelic TP53 loss, CK (P&gt;0.9), monosomal karyotype (MK, P&gt;0.9), del 5q (P=0.6), del 7q (P=0.4), and del 17p (P=0.2) were comparable between MDS-EB1 and -EB2 with VAF ≥10%. Importantly, median OS of MDS-EB1 and EB2 with VAF ≥10% was comparable (9.6 vs. 7.2 months, P=0.12). OS in this group was comparable regardless of the blast %, allelic status, or presence of CK.AML with VAF ≥10% had extremely poor survival: Median OS was 3.9 months. Survival of AML was equally poor irrespective of the mono- or biallelic (3.6 vs. 3.9, P=0.89) and non-CK vs. CK (1.8 vs. 3.9 months, P=0.09). Combined, our model would acknowledge poor survival of 514 (89.1%) cases. In contrast, retrospective application of the 5th edition of the WHO classification (WHO-5) and International Consensus Classification (ICC) would classify only 211 (36.4%) and 468 (80.7%) cases as biallelic/multi-hit TP53mut MN, respectively. Finally, the Harrell's c-index of the proposed model, WHO-5, and ICC was 0.66, 0.571, and 0.617, respectively. Conclusion: We provide evidence for subsequent refinements in classifying MN harboring TP53mut. Our salient findings include: (i) acknowledgement of CK as ‘biallelic equivalent’ in MDS-LB; as well as EB1/EB2/AML with VAF 2 to &lt;10% cases; and (ii) demonstration of poor survival of MDS-EB1 and -EB2 with VAF ≥10% regardless of the allelic status. In conclusion, our proposed model acknowledged poor survival of a higher proportion of cases as TP53mut MN compared to the current models with a higher c- index.

Introduction: Somatic mutations in RAS pathway genes are present in ~30% of patients with chronic myelomonocytic leukemia (CMML) and are usually associated with myeloproliferative features. Whether mutations in distinct RAS pathway genes share similar genomic context and have similar implications remains unknown. Such an understanding might inform future studies evaluating genotype-specific therapies (RAS-codon specific and pan-RAS inhibitors) or cooperative leukemogenic mechanisms. This multicenter study examines the landscape of RAS pathway mutations (RASMT) in CMML. Methods: Newly diagnosed CMML patients evaluated at MD Anderson Cancer Center (n=449, 54%) and Mayo Clinic (n=383, n=46%) were included after IRB approval. Clonal relationships were tested using Pearson goodness-of-fit. Clones with the highest variant allele frequency (VAF), or with VAF close to 40% were defined as dominant, and those present at VAF &lt;20% in the presence of another dominant clone were defined as subclonal. RASMT genes included NRAS, KRAS, BRAF, CBL, CBLC, PTPN11 and NF1. Standard statistical measures were applied. Results: Among 832 CMML patients (median age 71 years, 68% male) 387 (47%) had myeloproliferative (MP) and 445 (53%) had myelodysplastic (MD) CMML. A total of 350 (42%) patients had RASMT with higher prevalence among MP-CMML compared to MD-CMML (55% vs 31%, p&lt;0.001). Among patients with RASMT, 262 (32%), 59 (7%), 20 (2%), 6 (&lt;1%) and 3 (&lt;1%) had 1, 2, 3, 4 or 5 distinct RASMT, respectively. Importantly, 17 patients harbored a RASmt as the only detectable somatic mutation, with KRASMT being the most frequent (n=10, 59%), including 3 (18%) patients with &gt;1 RASMT. Among RASMT patients, a trend for higher hemoglobin (12.7 vs 10.8 g/dL, p=0.054) was observed in NF1MT CMML and lower WBC (14.4 vs 27.9 x109/L, p=0.067) values in CBLMT CMML. In total, 479 somatic mutations in RAS pathway genes were identified the most frequent involving NRAS (n=169, 35%) followed by CBL (n=120, 25%), KRAS (n=102, 21%), PTPN11 (n=38, 8%), NF1 (n=34, 7%), BRAF (n=11, 2%) and CBLC (n=5, 1%). Most frequently involved codons for each RAS pathway gene were as follows: G594 (n=3) for BRAF, R420 (n=22) and C404 (n=15) for CBL, G12 (n=41; G12D: 13, G12C: 3) and A146 (n=16) for KRAS, G12 (n=116; G12D: 74, G12C: 5) for NRAS and A72 (n=8) for PTPN11. CBLMT CMML had higher ASXL1 (58% vs 44%, p=0.011), BRAF (8% vs 4%, p=0.017), IDH2 (10% vs 4%, p=0.024), KIT (5% vs 1%, p=0.038), SRSF2 (54% vs 40%, p=0.004), TET2 (59% vs 47%, p=0.019) and ZRSR2 (10% vs 4%, p=0.014) co-mutation frequency. Of note, DNMT3A mutations were mutually exclusive of CBLMT CMML (0% vs 7%, p=0.007), and multihit TET2 was more common among TET2MT/CBLMT vs TET2MT/CBLWT CMML (82% vs 67%, p =0.039). CMML with NF1 mutations had higher BCORL1 (8% vs 0%, p=0.005), PTPN11 (15% vs 3%, p=0.014) and SETBP1 (23% vs 8%, p=0.022) mutational cooccurrences. NRASMT CMML was enriched for ASXL1 (53% vs 43%, p=0.042), ETNK1 (5% vs 1%, p=0.004), GATA2 (4% vs 1%, p=0.034) and STAG2 (4% vs 1 %, p=0.023) mutations but had lower JAK2 (1% vs 6%, p=0.036) and TP53 (1% vs 5%, p=0.022) mutational frequency. PTPN11 mutations were associated with higher NF1 (29% vs 7%, p=0.014), SETBP1 (27% vs 9%, p=0.01) and WT1 (6% vs &lt;1%, p=0.014) mutational cooccurrences and lower SRSF2 (23% vs 42%, p=0.05) frequency. We evaluated RAS mutant clonal dominance in 253 (72%) RASMT patients. NRAS (63% vs 38%), KRAS (63% vs 38%) and CBL (65% vs 35%) mutations were more frequently observed as dominant clones while PTPN11 (44% vs 56%), BRAF (25% vs 75%) and NF1 (35% vs 65%) mutations were more frequently subclonal events, particularly of TET2, ASXL1 or SRSF2 mutant clones. Presence of a RAS pathway mutation was associated with shorter LFS (36 vs 53 months, HR 1.5, 95% CI 1.1-2.2, p=0.020), with presence of multiple RAS mutations shortening LFS further (53, 43, 27 months for 0, 1 and &gt;1, p=0.017). PTPN11 mutations predicted for shorter OS (18 vs 39 months, HR 1.7, 95% CI 1.0-2.8, p=0.035) and LFS (14 vs 36 months, HR 1.9, 95% CI 1.2-2.9, p=0.008). Presence of &gt;1 RAS pathway mutation was associated with shorter OS in ASXL1MT/TET2MT CMML compared to those with no RAS mutations (24 vs 53 months, HR 4.2, 95% CI 1.6-10.8, p=0.004). Conclusions: RAS mutations exhibit distinct genomic features and clonal hierarchy in CMML and cooperate with other somatic mutations to drive clinical outcomes. This study forms the foundation for assessment of novel RAS pathway inhibitors in CMML.

Background: Chimeric antigen receptor T-cell (CAR-T) therapy has shown substantial promise in treatment of hematological malignancies, including non-Hodgkin Lymphoma (NHL). A subset of patients develop prolonged cytopenia, comprising quality of life, increasing healthcare utilization, and imparting considerable morbidity and mortality. Therapy-related myeloid neoplasms (t-MN), typically seen in patients who receive DNA-damaging agents such as radiotherapy and alkylators, have also been observed in CAR-T recipients. CAR-Hematotox score predicts the development of hematotoxicity in CAR-T recipients using laboratory parameters obtained at lymphodepleting (LD) chemotherapy, a timepoint when the patient has already gone through leukapheresis thus committed to the CAR-T process. Therefore, it is critical to identify patients at the highest risk of prolonged cytopenia and/or t-MN prior to apheresis, making it possible for a better triage of those who will proceed with CAR-T and those who might benefit from other strategies. Methods: A retrospective analysis was conducted in NHL patients who received commercial CAR-T products between January 2018 and March 2024 at Mayo Clinic Rochester, Arizona and Florida. Clinical and laboratory data including age, hemoglobin (Hb), absolute neutrophil count (ANC), platelet (PLT), ferritin, and LDH, obtained at the initial CAR-T evaluation, typically within 1 week of leukapheresis, were used for analysis. Prior lines of therapies including autologous stem cell transplant (ASCT) were collected. Prolonged cytopenias were defined as Hb &lt; 8 g/dL, ANC &lt; 0.5 x 109/L, and/or PLT &lt; 50 x 109/L at 3 months after CAR-T. t-MN was diagnosed per WHO 2016. For prolonged cytopenia, the optimal cutoff points for continuous variables were determined by maximizing the sum of sensitivity and specificity. Logistic regression was then used to determine the factors associated with cytopenia at 3 months post-CAR-T. For t-MN, maximally selected log-rank statistics was used to determine the optimal cutoffs. We used competing risk analysis to determine the factors associated with development of t-MN. Death without t-MN was considered a competing risk. For both analyses, the factors with P &lt; 0.1 in univariate analysis (UVA) were included in multivariate analysis (MVA). Results: Among the 387 NHL patients, with a median follow-up of 11 months (95% CI 8.7 - 12.2 months), 56 (14.4%) developed (41, 10.5% with 1 cytopenia; 14, 3.6% with 2 and 1, 0.2% with cytopenia in all 3 lineages), 20 (5.2%) developed and 315 (81.2%) did not have either. Factors associated with prolonged cytopenia: were age &gt;, PLT ≤ 150, ferritin ≥ 600, and LDH ≥ 250. Univariate analysis identified baseline Hb, ANC, PLT and ferritin to be significantly associated with prolonged cytopenia. MVA identified Hb ≤ 11 (HR = 1.98; 95% CI 1.03-3.85, P = 0.042) and PLT ≤ (HR = 2.56; 95% CI 1.39-4.78; P = 0.003) to be associated with the development of prolonged cytopenia. Factors associated with t-MN:were age &gt; 65 years, Hb ≤ 9 g/dl, ANC &lt; 3.8, PLT ≤ 80, Univariate analysis identified age, Hb, ANC, PLT, ferritin, and ≥ 3 prior lines of treatment to be significantly associated with t-MN. On MVA, age ≥ 65 (HR = 3.91; 95% CI 1.52-10.03; P = 0.004), Hb ≤ 9 (HR = 3.49; 95% CI 1.38-8.85; P = 0.008), ferritin ≥ 300 (HR = 3.06 ; 95% CI 1.08-8.67; P = 0.035) and ≥ 3 prior lines of therapy (HR = 3.25; 95% CI 1.33-7.94 ; P = 0.010) were associated with t-MN development. Association of prolonged cytopenia with t-MN development: Prolonged cytopenia was noted in 45% of patients who developed t-MN and 15% of those who did not (P = 0.002). Cumulative incidence of t-MN at 1 year was 3.3% and the presence of prolonged cytopenia was associated with a higher 1of t-MN (HR 8.93, 95% CI 2.15 - 37.1, P = 0.003). Conclusions: Readily accessible clinical and lab data such as blood count and inflammatory markers at the time of CAR-T evaluation were associated with the development of prolonged cytopenias. Similarly, advanced age, anemia, high ferritin levels and history of ≥3 lines of therapy were associated with the development of t-MN. These findings, when validated in larger dataset, can be used for patient counseling and therapy selection by identifying patients at high-risk of developing hematotoxicity and/or t-MN development.

Background Venetoclax + hypomethylating agent (Ven-HMA) therapy results in favorable response rates (CR/CRi 66%) and overall survival (OS; median 14.7 months) in unfit patients with newly-diagnosed acute myeloid leukemia (ND-AML; N Engl J Med 2020;383). However, there is substantial heterogeneity in individual patient outcomes based on response to treatment. The objective of the current study was to develop a genetic risk model to predict survival outcome in treatment responders and non-responders, analyzed separately, and also account for allogeneic stem cell transplant (ASCT). Methods Treatment-naïve AML patients receiving Ven-HMA, outside of a clinical trial, at the Mayo Clinic, USA (MN, AZ, FL) were retrospectively recruited. Molecular studies (48-gene panel) were performed by next-generation sequencing. Response was assessed according to the 2022 European LeukemiaNet (ELN) criteria (Blood 2022;140). Standard statistical analyses were performed using JMP Pro (Version 17.0.0). Results 400 ND-AML patients (median age 73 years, 64% male, 60% de novo) received Ven-HMA. ELN cytogenetic risk included favorable 2%, intermediate 60%, or adverse 38%. Mutations involved TP53 in 26%, TET2 19%, RUNX1 19%, SRSF2 18%, ASXL1 18%, DNMT3A 15%, K/NRAS 13%, NPM1 12%, IDH2 12%, FLT3-ITD 10%, IDH1 7% and DDX41 in 4% of informative cases. 153 (38%) patients achieved CR, 94 (24%) CR with incomplete count recovery (CRi), resulting in CR/CRi in 247 (62%) patients. CR/CRi rates were higher with NPM1 (86% vs 59%), IDH2 (77% vs 60%), and DDX41 mutations (93% vs 61%) and lower with TP53 (45% vs 67%), FLT3-ITD (41% vs 64%), RUNX1 (49% vs 65%) mutations and adverse karyotype (48% vs 71%), with all retaining significance in multivariable analysis. CR/CRi rate was highest (87%) in 75 patients with one or more favorable mutations (NPM1, IDH2, DDX41) and no unfavorable mutation (TP53, FLT3-ITD, RUNX1). CR/CRi rate was lowest in 171 patients with at least one unfavorable mutation and no favorable mutation (44%; p&lt;0.01). After a median follow up of 10.5 months (0.5-66), 105 relapses (43% of patients in CR/CRi), 248 (62%) deaths and 65 (16%) ASCT were documented. Univariate analysis for transplant-censored OS disclosed superior survival in patients achieving CR/CRi (median 21 vs 3.6 months; HR 5.4, 95% CI 4.1-7.1). Among patients achieving CR/CRi, IDH2 mutation was associated with superior (median not reached vs 20.5 months) and male gender (median 17.6 vs 29.2 months), TP53 mutations (median 11.9 vs 24.3 months) and adverse karyotype (median 12.6 vs 29.4 months) with inferior survival; multivariable analysis resulted in HRs (95% CI) of 2.1 (1.3-3.4) for male gender, 2.1 (1.2-3.8) for adverse karyotype, and 2.5 (1.1-5.7) for absence of IDH2 mutations. Male gender did not show an association with karyotype, or TP53 mutations (p&gt;0.1). Accordingly, an HR-weighted genetic risk model was generated with assignment of one point each to male gender, adverse karyotype, and absence of IDH2 mutation: high risk = 3 risk factors (n=38; median 9.6 months; 3-year survival 0%); intermediate risk = 2 risk factors (n=129; median 22 months; 3-year survival 38%); and low-risk = ≤1 risk factor (n=78; median not reached; 3-year survival 69%; p&lt;0.01). In patients bridged to ASCT (n=60), post-transplant survival was inferior in the presence of ≥ 2 risk factors (n=42; median 46 months) vs. ≤1 risk factor (n=18; median not reached; p=0.1). In patients not achieving CR/CRi, risk factors for OS included male gender (median 3.4 vs 6.1 months), adverse karyotype (median 3.3 vs 4.5 months) and TP53 mutation (median 3.1 vs 4.5 months) while those with IDH2 mutations lived longer (median 8.4 vs 3.4 months). In multivariable analysis, HRs (95% CI) were 1.9 (1.3-2.9) for male gender, 2.0 (1.4-2.9) for adverse karyotype, and 2.1 (1.1-4.3) for absence of IDH2 mutations. OS was shortest for non-responders harboring 3 risk factors (n=45; median 3 months; 1-year survival 0%) and longer for those harboring two (n=80; median 6 months, 1-year OS 15%) or ≤ 1 risk factor (n=25; median 14 months; 1-year OS 56%; p&lt;0.01). Conclusion The current study describes a molecular profile for predicting response to Ven-HMA in ND-AML and also introduces a novel approach to survival prediction that considers treatment response as the starting point. In both responders and non-responders, male gender and adverse karyotype were identified as unfavorable and IDH2 mutation favorable risk factor for OS.

INTRODUCTION While prognostic understanding (PU) is important for all patients (pts) considering hematopoietic stem cell transplantation (HCT), it may be particularly important for older (&gt;65 years), medically infirm, and/or frail pts deciding whether to undergo allogeneic HCT (allo-HCT). This abstract reports on PU and concordance with transplant physician (hereafter MD) PU for pts participating in an ongoing seamless, phase II-III randomized clinical trial (ACE-BMT) comparing 4-arms: a pt-administered comorbidity management intervention (CM), specialist-administered palliative care (PC), a combined arm of CM and PC to standard of care. Here we report preliminary data on the concordance between pt and MD PU on the chance of cure 1-year (yr) post allo-HCT. METHODS Pt PU was compared to MD PU (gold standard) to determine concordance. MD and pt answers were compared on a single validated question asked at enrollment to the study (typically 2 weeks prior to HCT). Both pts and MD's estimated the chance of cure 1 yr after allo-HCT by selecting one of six possible response options: very good (more than 90%), good (75-90%), better than 50% (50-74%), worse than 50% (25-49%), bad (10-24%) or very bad (less than 10%). PU was “concordant” or “accurate” if MD and pt selected the same response option. Pts with discordant PU were labeled “pessimistic” if the pt selected a response option with a lower chance of cure than the MD (and “optimistic” if a higher chance). Response options were further simplified to greater than or less than 50% chance of cure and MD and pt PU were compared again. Descriptive statistics, chi-square for categorical and t-tests for continuous variables were used. Logistic regression was used to determine the association between pt prognostic concordance and pt socio-demographic and clinical characteristics. RESULTS All pts consented to date were included (n=358), except those who did not answer the prognosis question (n=61). 54.2% (n=194) had HCT-Comorbidity Index (HCT-CI) of ≥3, 67.9% (n=243) were older than 65 yrs and 4.5% (n=16) were frail, defined by walk speed &lt;0.8 m/s. Median age was 68 yrs (range 20-80). 39.7% (n=141) were female. 89.9% (n=322) identified as White, 4.2% (n=15) Asian, and 1% each as Black/African American and Native Hawaiian/Other Pacific Islander. 5.3% (n=19) identified Hispanic. 11.5% (n=44) had high school education or less. 54.1% (n=183) made less than $100,000/yr. 40.1% (n=136) had acute myelogenous leukemia, 25.4% (n=86) had high-risk myelodysplastic syndrome and 10.6% (n=36) had a myeloproliferative cancer. 72.1% (n=245) had matched, 82.5% (n=283) unrelated and 95.0% (n=36) peripheral blood allo-HCT. 9% (n=31) had KPS of 100%, 35% (n=121) KPS 90%, and 47.5% (n=147) KPS 80%. Pts reported having a very good, good, better than 50%, worse than 50% and bad/very bad chance of cure 1 yr post allo-HCTL 34.4% (n=123), 30.7% (n=110), 26.0% (n=93), 7.3% (n=26) and 1.7% (n=6), respectively. 91.1% (n=326) of pts felt they had a &gt;50% chance of being cured 1 yr post allo-HCT. MD answers were missing for 159/358 (44.4%) pts. MDs reported pt had a very good, good, better than 50%, worse than 50% and bad/very bad chance of being cured 1 yr post allo-HCT, 3.0% (n=6), 6.5% (n=13), 52.8% (n=105), 35.7% (n=71) and 2% (n=4) respectively. 62.3% (n=124) of MDs felt the pt had a &gt;50% chance of being cured 1 yr post allo-HCT. For the subset of pts with MD prognostic data (n=199), pt's PU was concordant 20.6% (n=41) of the time when compared across all 6 response options. Overall, 71.9% (n=143) of pts erred toward optimism, while 7.5% (n=15) of pts were pessimistic. 60.8% of MD and pts agreed on prognosis when dichotomized to better or worse than 50% chance of being cured 1 yr post allo-HCT. Prognostic concordance was not significantly associated with any pt socio-demographic factors, HCT-CI or KPS via descriptive statistics or regression analysis. CONCLUSIONS In this prospective randomized trial focusing on a population of older, medically infirm, and/or frail pts receiving allo-HCT, pts' PU was not concordant with MD prognosis approximately 80% of the time. While some pts were pessimistic, the majority overestimated the likelihood they would be cured of disease compared to MD estimates. Future studies should investigate the true accuracy of both MD and pt prognosis, as well as how to improve communication about prognosis and pt PU (if inaccurate based on best available information) prior to HCT.