Zeidner, Joshua F.

Abstract Introduction: HMA monotherapy (HMAm) continues to be the standard of care for HR-MDS. While the addition of VEN to azacitidine (AZA) improved overall survival (OS) and complete remission (CR) rates among older pts with acute myeloid leukemia (AML) over AZA monotherapy, the recently completed phase III VERONA trial of AZA+/-VEN in HR-MDS failed to show an OS benefit for AZA/VEN over AZA monotherapy. Using the icMDS VALIDATE database, we compared outcomes of pts with HR-MDS treated with HMA or HMA/VEN as frontline therapy. Methods: The icMDS VALIDATE database includes over 4000 adult MDS pts who received HMA-based therapy from 32 international centers in 9 countries. For this analysis, we included pts with HR-MDS defined by International Prognostic Scoring System [IPSS] ≥1.5 or IPSS-revised [IPSS-R] ≥4 (at diagnosis or HMA initiation) and treated with HMAm or HMA/VEN as frontline therapy for HR-MDS. We assessed responses based on IWG 2023 criteria (Zeidan A et al, Blood 2023). Composite complete remission (cCR) was defined as CR+CRbi+CRuni+CRh+CRequivalent. We calculated OS from time of HMA initiation to date of death from any cause. Pts lost to follow-up were censored at the date they were last known to be alive. We used Kaplan-Meier methods to calculate OS and compared OS between different groups using the log-rank test. We used Cox and logistic regression models to adjust for baseline prognostic variables as appropriate. The study was funded by an independent grant from Abbvie. Results: A total of 1907 pts met eligibility and were included (1552 AZA, 221 decitabine, 134 HMA+VEN). 479 pts subsequently underwent allogeneic stem cell transplant (allo-SCT; 430 after HMAm [32.6%]; 49 after HMA/VEN [37.1%]). Our cohort was enriched for pts with adverse disease characteristics including complex karyotype (33.6%) and TP53 mutations (28.7%). Compared to pts treated with HMA/VEN, pts treated with HMAm were more likely to be male (p=0.012), have lower baseline platelet counts (p=0.037), peripheral blood (PB) blasts (p=0.004), or bone marrow blasts (p<0.001), and were less likely to have very high risk IPSS-M (p<0.001), TP53 mutations (p<0.001), or complex karyotype (p=0.020). In unadjusted analyses, the rate of cCR was significantly lower in HMAm treated pts compared to HMA/VEN treated pts (27.7% vs. 48.8%, p<0.001). However, CR rate was not significantly different (11.7% vs. 17.1% for HMAm and HMA/VEN, respectively, p=0.22). After adjusting for age, sex, and IPSS-M, pts treated with HMA/VEN were more likely to achieve cCR compared to HMAm with an odds ratio (OR) of 2.49 (95% CI: 1.56-3.96, p<0.001). When separated by TP53 mutation status, the OR for cCR for HMA/VEN vs HMAm was 4.17 (95%CI: 2.14-8.31; p<0.001) and 1.27 (95%CI: 0.54-2.86; p=0.57) for TP53 wild-type and TP53-mutant pts, respectively. In unadjusted analyses, median OS was 17.4 months for HMAm and 19.6 months for HMA+VEN, and OS did not differ significantly by treatment type (p=0.33). For HMAm treated pts, the OS rates at year 1, 2, 3 were 0.65 (95%CI: 0.63-0.67), 0.38 (95%CI: 0.36-0.40), and 0.27 (95%CI: 0.25-0.29), respectively. For HMA/VEN treated pts, the OS rates at year 1, 2, 3 were 0.64 (95%CI: 0.56-0.73), 0.45 (95%CI: 0.36-0.56), and 0.37 (95%CI: 0.27-0.51), respectively. In a multivariate analysis adjusting for age, sex, PB blast, IPSS-M and allo-SCT as a time-varying covariate, treatment with HMA/VEN vs HMAm did not significantly influence OS (hazard ratio (HR) of OS for HMA/VEN vs HMAm: 0.89, 95%CI: 0.69-1.13, p=0.33). When stratified by TP53 mutation status, HR of HMA/VEN vs. HMAm was favorable for TP53 wild-type (HR: 0.47; 95%CI: 0.29-0.74) but not TP53-mutant pts (HR=0.96; 95%CI: 0.66-1.41). Adjusting for other variables in the model, HR for pts who underwent vs. those who did not undergo allo-SCT were 0.65 (95% CI: 0.49-0.85) and 0.36 (95%CI: 0.24-0.53) in TP53 wild-type and mutant patients, respectively. Conclusion: In this large, international retrospective analysis from the icMDS VALIDATE database, HMA/VEN was associated with higher cCR rates—but not CR rates—compared to HMAm among pts with HR-MDS, though we observed no significant differences in OS. In our analysis, clinical benefit from the addition of VEN was most clear in TP53 wild-type pts, and allo-SCT was associated with improved OS regardless of baseline TP53 status. Our analysis was limited by the relatively small number of HMA/VEN-treated pts and heterogeneous real-world treatment patterns.

Abstract Introduction TP53MT are associated with poor outcomes in MDS, especially in the context of biallelic MT. We have previously reported on outcomes of pts with HR-MDS with TP53MT who received HMA in the VALIDATE dataset (Kewan T et al, ASH 2023). Here we provide expanded analyses focusing on outcomes post allo-HCT, and we explore the prognostic significance of different classification methods for biallelic TP53MT. Methods The VALIDATE database includes 4,732 pts with MDS who received HMA-based frontline therapy from 32 international centers in 9 countries. For this study, only pts with HR-MDS with molecular data at time of diagnosis were included. Biallelic TP53MT status was assessed using three classification schemes: WHO 2022, ICC 2022, and a VAF-based Cleveland Clinic Foundation (CCF) method.1TP53 copy neutral loss of heterozygosity (CN-LOH) was evaluable in 386 pts (118 had TP53MT). Treatment responses were evaluated using IWG 2023 criteria (Zeidan A et al, Blood 2023). Composite complete remission (cCR) was defined as CR+CRbi+CRuni+CRh+CRequivalent. We calculated OS from time of HMA initiation to date of death or last follow up. Unsupervised clustering (MOSAIC framework) was applied to identify molecular subgroups within the TP53MT cohort. The study was funded by an independent grant from Abbvie. Results A total of 1,485 pts were included. Median age was 69 years (IQR: 62–76), with 66% male pts. Median bone marrow blast was 7%, and 28% had a complex karyotype. Treatment regimens included azacitidine (68%), decitabine (15%), HMA/Venetoclax (8%), and other HMA combinations (9%); 34% underwent allo-HCT. Overall, 392 (26%) had TP53MT with 430 TP53 mutations (missense: 316; truncating: 89). Biallelic TP53MT % varied by classification: 72% (WHO), 84% (ICC), and 85% (CCF). Compared to TP53 wild-type (TP53WT) pts, pts with TP53MT had worse OS (median: 11.5 vs. 23.9 months [mo], p< 0.001), were younger (68 vs. 70 years, p=0.039), and had lower counts at diagnosis. Complex karyotype (81% vs. 14%) and chromosomal abnormalities were more frequent in TP53MT pts. Pts with TP53MT also had fewer co-mutations in other genes. Response to HMA was evaluable in 1,094 pts: cCR and CR were 32% and 13%, respectively. TP53MT pts had higher cCR (39% vs. 29%, p=0.001) than TP53WT, but similar CR rates (16% vs. 12%, p=0.093). According to WHO 2022, biallelic TP53MT had higher CR rates than monoallelic TP53MT (18% vs. 8%, p=0.03), but similar cCR. ICC and CCF classifications did not differentiate response rates. Median OS did not differ by TP53MT allelic status using WHO or ICC definitions. However, using the CCF method, pts with biallelic TP53MT had shorter OS than monoallelic TP53MT (10.4 vs. 17.2 mo, p=0.038). In multivariable models adjusted for age, gender, and allo-HCT, only the CCF-defined biallelic TP53MT group had significantly worse OS (HR: 1.6; 95% CI: 1.1–2.4). TP53MT pts undergoing allo-HCT had improved OS regardless of allelic status. Median OS for TP53MT pts with allo-HCT was 18.9 vs. 9.2 mo without all-HCT. This benefit was observed across WHO, ICC, and CCF classifications. However, a TP53MT VAF ≥19% predicted worse OS even post allo-HCT (14.6 vs. 47.1 mo, p<0.001). At 1 year, the survival rate was 78% (95%CI: 69-89%) in TP53MT pts who underwent allo-HCT and had cCR vs. 68% (95%CI: 55-84%) in pts who did not have cCR. However, 1 year survival rate was significantly higher for pts with TP53MT who did not have allo-HCT and achieved cCR (60%, 95%CI: 48-76%) vs. no cCR (26%, 95%CI: 20-35%). Unsupervised clustering of 335 TP53MT pts identified 9 molecular clusters (MCs). MC2, characterized by low TP53MT VAF (median 17%), fewer co-mutations, and frequent del17p, was associated with significantly improved OS (17.9 mo) and predicted favorable outcome (HR for death: 0.6; 95% CI: 0.4–0.8). Other clusters were enriched for adverse features (e.g., high VAF, multi-hit TP53MT).Conclusions The CCF method appears to best classify biallelic TP53MT pts with worse survival in the absence of accurate assessment of LOH status. Treatment response per IWG 2023 for TP53MT pts was associated with OS only in non-transplanted pts. Allo-HCT improved survival across TP53MT subsets, but TP53 VAF ≥19% at diagnosis remained a strong negative prognostic factor. Integrative clustering revealed a less aggresive molecular subset among TP53MT pts, suggesting refined risk stratification may guide therapy in this high-risk population. Ref: 1.Bahaj et al. J Hematol Oncol 2023.

Abstract Introduction: Marrow complete remission (mCR) in 2006 IWG criteria for MDS (Cheson B et al, Blood 2006) reflects achieving bone marrow (BM) blast percentage below 5% but is frequently not associated with meaningful count recovery. While mCR + hematologic improvement (HI) does reflect wide ranges of count improvement or transfusion reductions, HI is difficult to measure accurately in routine clinical practice. The 2023 International Working Group (IWG) response criteria (Zeidan A et al, Blood 2023) eliminated the mCR category without meaningful count recovery and reclassified mCR associated with meaningful count recovery into specific “less-than-CR” categories. Still, many clinical trials continue to use mCR as a secondary efficacy endpoint or as a part of overall response rate (ORR). Within the icMDS VALIDATE database, we assessed the association of mCR with OS in hypomethylating agent (HMA)-treated higher risk (HR)-MDS patients among both (1) transplanted and (2) non-transplanted patients. Methods We included patients with HR-MDS (defined as IPSS ≥1.5 and/or IPSS-R >3.5) who received HMA-based therapies from the international icMDS VALIDATE dataset. We evaluated the best response by IWG 2006 criteria into CR, mCR, or no CR/mCR. We then reclassified patients with mCR per IWG 2023 criteria into either (A) having achieved a composite CR (cCR) defined as CR + CR equivalent (CRequ) + CR with bilineage count recovery (CRbi) + CR with unilineage count recovery (CRuni) + CR with partial hematologic recovery (CRh) or (B) not having achieved cCR (no cCR). OS was calculated from time of HMA initiation to date of death or last follow-up by using 6-month landmark analyses. We used Kaplan-Meier methods to estimate OS, and the Log-rank test to compare OS. VALIDATE is supported by an independent grant from AbbVie. Results A total of1049 patients met eligibility.Median age of patients was 69 (range 21-95), 64% were men. While 61% received azacitidine, 17% received decitabine, and 22% received HMA-based combination therapy. In total, 37% underwent subsequent allogenic stem cell transplantation (allo-HCT). Based on IWG 2006 criteria, 17%, 33%, and 50% achieved CR, mCR, and no CR/mCR as their best response, respectively. Patients achieving CR had superior median OS (25 months, 95% CI: 21-34 months) compared to those with mCR (16 months, 95% CI: 13-18 months; p=0.038) and no CR/mCR (15 months, 95% CI: 12-17 months; p=0.001). In patients who received a subsequent allo-HCT, the median OS for patients with mCR (30 months, 95% CI: 21-54 months; 1 year OS: 71%, 2 year OS: 55%) did not significantly differ compared to patients with CR (59 months, 95% CI: 25 months-not reached, p=0.80; 1 year OS: 73%, 2 year OS 62%) and patients with no CR/mCR (32 months, 95% CI: 21-45 months, p=0.46; 1 year OS: 69%, 2 year OS 54%). In contrast, in patients treated with HMA therapy alone without subsequent allo-HCT, median OS for patients with mCR (11 months, 95% CI: 9-15 months; 1 year OS: 46%, 2 year OS: 23%) did not significantly differ compared to patients with no CR/mCR (11 months, 95% CI: 9-14 months, p=0.85; 1 year OS: 47%, 2 year OS: 22%) but was significantly shorter compared to patients with CR (20 months, 95% CI: 17-28 months, p<0.001; 1 year OS: 69%, 2 year OS: 46%). Patients with mCR by IWG 2006 (N=347) were reclassified per IWG 2023 into having either achieved a cCR (N=219, 63%) or no cCR (N=128, 37%). Specifically, patients with mCR were reclassified per IWG 2023 into CR (4.9%), CRequ (0.6%), CRbi (26.8%), CRuni (29.4%), CRh (1.4%), PR (0%), HI (10%), no response (21.9%) and PD (4.9%). Patients with mCR who were reclassified into cCR had an improved median OS (16 months, 95% CI: 15-26 months; 1 year OS: 62%; 2 year OS: 43%) compared to patients reclassified into no cCR per IWG 2023 (13 months, 95% CI: 11-17 months, p=0.023; 1 year OS: 52%; 2 year OS: 31%). Conclusions Using the large icMDS VALIDATE dataset, we found that achievement of mCR by 2006 IWG criteria was not associated with improved OS compared to patients who did not achieve CR/mCR. Reclassification of mCR using IWG 2023 highlights the heterogeneity within the mCR group and suggests that IWG 2023 criteria stratifies outcomes in patients previously labeled as mCR by IWG 2006. IWG 2023 should be the standard used for ORR assessment in all future clinical trials involving patients with HR-MDS.

Background: The BeatAML Master Trial (BAMT) began in 2016 with a goal of determining the feasibility of a precision-medicine approach in treating acute myeloid leukemia (AML) in older adults ≥ 60 years of age where outcomes are poor. At the time, standard of care (SOC) for older patients with AML was intensive 7+3 chemotherapy (cytarabine + daunorubicin) if fit and hypomethylating agents (HMA: azacitidine or decitabine) if unfit. Besides confirming the feasibility, the early results (2019) from the Master Trial suggested that patients who received therapy on one of the sub-studies had a lower early death rate and superior overall survival compared to patients receiving off-protocol SOC, which was primarily single-agent HMA at the time. Since then, the 2019 approval of venetoclax (ven) + azacitidine for older unfit AML patients has been transformative and emerged as the SOC. Using data from the BAMT from 2016-2024, we suggest that knowing the comprehensive genomic profile of AML at the time of diagnosis is still beneficial in determining therapy that would lead to the optimal outcome and that development of targeted therapies and combination regimens with ven/HMA is still needed. Methods: This is a retrospective analysis of 1096 patients who consented and enrolled on the BAMT (NCT03013998) from Nov 2016 through Jun 2024. Patients ≥ 60 years with newly diagnosed AML were included. Patients underwent therapy on a BeatAML sub-study based on their genetics (N=433) or treatment off-protocol (N=663). We divided the patients according to what therapy they received: (1) Non-Intensive (Off-Protocol, N=121), (2) Ven/HMA (Off-Protocol, N=234), (3) Non-Intensive (Sub-Study, N=407), (4) Intensive (Sub-Study, N=26), and (5) Intensive (Off-Protocol, N=155). 94 patients received no treatment and 59 were unknown. Non-intensive therapies included primarily targeted agents or non-ven combinations. We analyzed baseline characteristics and demographics, overall survival (OS), and the impact of allogenic stem cell transplant (SCT). OS, using Kaplan-Meier method, was measured from the start of therapy to all-cause death, censoring patients at last follow-up. Results: Characteristics and demographics were similar between Groups 1, 2 and 3. Group 4 and 5 were treated with intensive chemotherapy and their characteristics are reflective of younger/fit patients appropriate for the intensive regimen. Groups 4 and 5 also had the longest median OS (mOS) of 40.2 months (95% CI: 13.9-not reached (NR)) and 42.3 months (95% CI: 25.1-NR) respectively. Group 3, which included patients treated with a non-intensive, targeted therapy on a sub-study, had an mOS of 14.0 months (95% CI: 12.3-16.7), which was similar to Group 2, treated with Ven/HMA, that had an mOS of 13.2 months (95% CI: 10.9-16.3). Lastly, patients in Group 1, who were treated primarily with HMA monotherapy, did poorly in comparison, with an mOS of 6.0 months (95% CI: 3.3-10.1). Additionally, we looked at the cumulative incidence rate (CIR) of SCT. The CIR in 12 months of Group 1 was 9.8% (95% CI: 6.9-13.4), Group 2: 5.4% (95% CI: 2.2-10.7), Group 3 and 4 combined: 35.0% (95% CI: 628.1-42.1), and Group 5: 13.1% (95% CI: 6.9-13.4). In a multi-variable analysis, after adjusting for typical favorable risk factors like NPM1 mutations and core binding factor, SCT was highly significant (p<0.0001) in improving OS with a hazard ratio of 0.23 (95% CI: 0.16-0.32), and Group 3 performed similarly to Group 2 (p=0.20). Conclusions: First, our results suggest that it is clinically relevant to correctly identify whether an intensive chemotherapy, targeted-therapy, or ven/HMA regimen is best suited for older AML patients, for which a precision-medicine trial is ideal for. Secondly, in this group of patients, our results show that patients treated with a non-intensive targeted therapy (Group 3) has a similar mOS to those treated with ven/HMA (Group 2). Especially after controlling for patient characteristics, patients in Group 2 performed similar to those in Group 3 (p=0.20). Patients in Group 3 were treated on Beat AML sub-studies which included targeted therapy alone or with non-venetoclax combinations, which is a strong rationale for continued development of targeted agents to optimize toxicity and quality of life with similar survival. Lastly, this data also supports the need to improve the ven/HMA SOC by developing combination regimens with targeted agents to further improve outcomes.

Background: Mutations of isocitrate dehydrogenase (IDH) are recurrent in acute myeloid leukemia (AML) and the prevalence increases with age. The prognostic impact of IDH1 and IDH2 mutations remains controversial. IDH inhibitors are small molecules that bind within the IDH enzymatic active site, blocking aberrant 2-hydroxyglutarate production and inducing myeloid differentiation. While they can lead to differentiation syndrome, they generally have a more favorable side-effect profile, making them an attractive option for older patients. We aimed to describe the prevalence and prognostic impact of IDH mutations in newly diagnosed (ND) AML patients ≥ 60 years in a large cohort of patients treated on a Leukemia and Lymphoma Society-sponsored trial. Methods: We performed a retrospective observational analysis including patients ≥ 60 years with ND AML who were enrolled on the Beat AML clinical trial (NCT03013998) before May 10, 2023. Patients were treated with a variety of treatment regimens. Cytogenetic analysis and next-generation sequencing (FoundationOne®Heme) were obtained. Mutations were considered present at any detectable VAF. Cox proportional hazard models were used to describe the relative risk of each variable on death over time from the date of trial inclusion. Results: A total of 1023 patients with ND AML were identified. Patients had a median age of 72 (range 60-92) years and the majority were non-Hispanic White (83.2%), and male (57.6%). Ninety-nine (9.7%) patients were IDH1MUT, 193 (18.9%) patients were IDH2MUT including 10 (1.0%) patients with a co-occurring IDH1 and IDH2 gene mutations. Both IDH1MUT and IDH2MUT were associated with 2022 ELN favorable-risk (26.3% and 22.3% for IDH1 and IDH2 respectively, vs 15.5% overall (P<0.001)). IDH1MUT significantly co-occurred with DNMT3AMUT (42.4%), NPM1MUT (44.4%) and less frequently with TP53MUT (10.1%) (P<0.001 for all). IDH2MUT was associated with DNMT3AMUT (35.8%), NPM1MUT (31.1%), SRSF2MUT (38.3%), and less frequently with TET2MUT (6.7%) and TP53MUT (9.3%) (P<0.001 for all). Normal karyotype was higher in IDH1MUT (P<0.001) and IDH2MUT (P<0.001), whereas complex karyotype (P<0.001 for both) and core-binding factor AML (P=0.047, P=0.015) were lower in IDH1MUT and IDH2MUT. To evaluate the impact of IDH mutations in patients ≥ 60 years, we focused on patients evaluable for outcome treated with lower-intensity therapy (LIT) (N=674), and intensive chemotherapy (IC) (N=178), separately. Among the LIT treated patients, 96 patients received treatment with an IDH inhibitor, and 237 patients received a hypomethylating agent (HMA) plus venetoclax. For patients treated with LIT, the hazard ratios (HRs) of death over time were 0.58 [95% CI 0.47-0.72; P<0.002], 0.81 [95% CI 0.59-1.13; P=0.214] and 0.56 [95% CI 0.44-0.72; P<0.001] for IDHMUT, IDH1MUT, IDH2MUT respectively. Among patients receiving IC, the HRs were 1.05 [95% CI 0.68-1.69; P=0.777], 0.70 [95% CI 0.31-1.61; P=0.406] and 1.27 [95% CI 0.77-2.1; P=0.352] for IDHMUT, IDH1MUT, and IDH2MUT respectively. The HR of death for IDH1MUT patients treated with LIT with the addition of an IDH1 inhibitor (N=24) was significantly lower (HR 0.47 [95% CI 0.24-0.92; P=0.027] vs IDH1MUT patients treated without an IDH1 inhibitor, while an IDH2 inhibitor did not change survivial outcomes in patients with IDH2MUT (N=71). Discussion: To our knowledge this is the largest retrospective study characterizing the prevalence of IDH mutations in patients ≥ 60 years with AML. We demonstrated that IDH mutations were detected in ~27% of older patients with AML. Although there could have been selection bias as the Beat AML study had separate IDHMUT study arms, these findings are concordant with other studies showing an increase in frequency of IDH mutations with age. IDH2MUT was associated with a lower HR of death among patients treated with LIT, which was not seen in patients receiving IC. The high prevalence of IDH mutations suggests that IDH inhibitors used as single agents or in combination with lower-intensity therapies are an important class of drugs for this older patient population as they are generally well tolerated, that need further investigation.

Introduction The International Prognostic Scoring System (IPSS) and its revised version (IPSS-R) were developed using datasets from patients (pts) with untreated MDS. The cytogenetic risk groups used in IPSS-R were expanded to 5 groups from the 3 used in IPSS. Among the new groups introduced in IPSS-R is the “very complex” karyotype (VCK) where ≥4 karyotypic abnormalities are seen compared to “complex karyotype (CK)” with only 3 abnormalities. However, the prognostic impact of VCK vs CK, as well as individual cytogenetic abnormalities and TP53 mutation (TP53mut) status within the CK and VCK subgroups in pts with MDS treated with hypomethylating agents (HMAs) has not been well studied. Hence, we analyzed these questions in a large cohort of HMA-treated MDS pts in the icMDS VALIDATE database. Methods The icMDS VALIDATE database contains MDS pts treated with frontline HMA monotherapy or HMA-based combinations from 22 specialized international centers. Pts with unknown HMA type, date of HMA initiation, missing age, missing sex, missing cytogenetic data, bone marrow or peripheral blood blasts ≥20%, or missing survival status were excluded. We performed time-to-event analyses using the Kaplan-Meier method and compared groups by the log-rank test. We measured overall survival (OS) from time of HMA initiation. VALIDATE protocol was exempted, acknowledged, or approved by all centers' IRBs. VALIDATE is supported by an independent grant from Abbvie. Results A total of 1940 pts were included. Median age was 70 (range: 18-99) years and 66% were men. According to IPSS-R cytogenetic risk groups, 1.9% (37) were very good, 43.4% (841) good, 15.5% (301) intermediate, 11.6% (226) poor, and 27.6% (535) very poor. By HMA type, 71% of pts were treated with azacitidine, 14% with decitabine, 6% with HMA and venetoclax, and 9% with another HMA combination. Approximately 28% of pts underwent allogeneic hematopoietic stem cell transplant (alloHSCT). The IPSS-R cytogenetic risk groups had different OS (p<0.001)with median OS (mOS; months [mo], 95% CI) as follows: very good (43.4, 34.7-72.5), good (41.7, 36.4-46.8), intermediate (24.5, 23.1-32.4), poor (24.2, 19.2-28.5), and very poor (13.6, 12.5-14.5). The difference remained significant (p=0.001) after censoring at time of alloHSCT with mOS as follows: very good (40.4, 23.2-64.3), good (24.3, 22.2-26.3), intermediate (19.3, 15.1-22.2), poor (12.2, 10.3-14.8), and very poor (9.1, 8.2-19.7). Interestingly, the difference between mOS for intermediate and poor risk cytogenetics became more apparent after censoring at time of alloHSCT. Next, we compared the outcomes of pts with CK and VCK to non-complex karyotype (NCK) MDS. The mOS for pts with VCK MDS (13.6 mo, 12.5-14.5) was worse compared to pts with CK (19.9 mo, 19.9-16.8; p=0.004) and NCK (36.1 mo, 32.7-37.8; p<0.001) MDS. Among the 1458 pts with available molecular data, more pts with VCK (75%, 330) MDS had a concurrent TP53mut compared to pts with CK (40%, 21; p<0.001) and NCK (7%, 64 p<0.001) MDS. Considering only patients with TP53mut MDS, mOS for pts with VCK (12.2, 11.1-13.9) was worse compared with NCK (24.2, 16-1-53.1; p<0.001) but not with CK (19.9, 9.5-NR; p=0.9); the difference between CK and NCK was not significant (p=0.16). Among pts with TP53 wildtype (TP53WT) MDS, VCK (15.0, 13.2-18.2) had a similar mOS to TP53WT CK (18.8, 12.6-41.1; p=0.19) while both groups had worse mOS compared to TP53WT NCK (33.4, 30.1-37.0) (p=0.01). In a survival analysis of 616 pts with MDS with ≥3 cytogenetic abnormalities, -17/del(17p) (12.8 mo; p=0.009), inv(3)/t(3q)/del(3q) (10.9 mo; p=0.006), and del(7q) (12.1mo; p=0.024), though not -7 (12.6mo; p=0.23), were associated with lower mOS compared to the pts with MDS without these abnormalities (14.3mo). Conclusions Using one of the largest databases of HMA-treated MDS pts, we show that IPSS-R cytogenetic risk categories associate with significantly different survivals among HMA-treated MDS pts, even after censoring at time of alloHSCT. Importantly, VCK MDS was associated with worse mOS compared to CK and NCK MDS but not in pts with a concurrent TP53mut. Among pts with MDS with ≥3 chromosomal abnormalities, having -17/del(17p), inv(3)/t(3q)/del(3q), or del(7q) was associated with worse survival.

Introduction: Response assessment is used to evaluate effectiveness of hypomethylating agent (HMA)-based therapy in myelodysplastic syndromes/neoplasms (MDS) in clinical practice and trials. Recently, the clinical response criteria (IWG 2023) and the clinical-molecular risk assessment (IPSS-M) in MDS were published. However, it remains unknown whether the IWG 2023 response criteria have an independent impact on overall survival (OS) when adjusting for baseline IPSS-M risk. Additionally, the association of IWG 2023 response criteria with OS in patients (pts) undergoing allogeneic stem cell transplantation (allo-HCT) versus those who do not is unknown. Lastly, it is unclear if optimal time-to-transplant impacts OS in MDS pts who achieve a IWG 2023 defined remission with HMA therapy. We examined these questions in a large population of MDS pts within the multi-institutional international consortium for MDS (icMDS) VALIDATE database. Methods: High-risk MDS pts with IPSS ≥1.5 or IPSS-R >3.5 treated with HMA-based therapy were included in the study. Baseline IPSS-M risk was stratified into very low/low/moderate low (VL+L+ML), moderate-high/high (MH+H), and very high (VH). Response to treatment was evaluated using the IWG 2023 criteria and grouped into: composite complete response (cCR) and no cCR. cCR included: complete response (CR), CR equivalent (CRequ), CR bilineage (CRbi), CR unilineage (CRuni), and CR with partial hematologic recovery (CRh). We analyzed the differential impact of achieving cCR on HMA-based therapy prior to transplant on OS in pts who either did or did not undergo allo-HCT, while adjusting for their baseline IPSS-M risk in Cox regression analysis. Optimal time-to-transplant was determined based on age and IPSS-M category as described by Tentori et al. (JCO 2024). Pts proceeding to allo-HCT were stratified on whether they underwent transplant within the optimal time-to-transplant timeframe after MDS diagnosis or not. VALIDATE protocol was exempted, acknowledged, or approved by all centers' IRBs. VALIDATE is supported by an independent grant from AbbVie. Results: We analyzed 762 MDS pts. The median age at MDS diagnosis was 68 years (range: 19-95 years) and 64% of pts were male. Distribution of the baseline IPSS-M risk was: VL+L+ML in 110 (14%) pts, MH+H in 347 (46%) pts, VH in 305 (40%) pts. Pts received azacitidine monotherapy, decitabine monotherapy, and HMA-based combination therapy (e.g. HMA + venetoclax) in 52%, 21%, and 28% of cases, respectively. A total of 282/762 (37%) pts achieved cCR as their best response to HMA-based therapy. The median OS for all pts was 18.7 months (95% CI: 16.6-21.3 months). Pts who did not undergo allo-HCT (n=436, 57%) had an improved median OS if they achieved cCR when compared to pts in the no cCR group in all IPSS-M risk groups (VL+L+ML: 23.5 months vs. 10.7 months; MH+H: 20.8 months vs. 11.6 months; VH: 13.8 months vs. 7.5 months). Cox analysis demonstrated an independent effect of cCR on OS in these pts when adjusted for baseline IPSS-M risk (cCR vs. no cCR: HR 0.60, 95% CI 0.48-0.76, p<0.001). In contrast, in pts who subsequently received an allo-HCT (n=326, 43%), achieving cCR with HMA prior to allo-HCT did not provide an additional OS benefit, when adjusted for baseline IPSS-M risk (cCR vs. no cCR: HR 1.00, 95% CI 0.73-1.38, p=0.986). The median time-to-transplant was 6.7 months and 34% of transplanted MDS pts received their allo-HCT during the optimal timeframe. Among pts who achieved cCR with HMA-based therapy prior to allo-HCT, optimal time-to-transplant was associated with significantly improved OS (optimal vs. non-optimal timing: HR 0.55; p=0.033). Conclusion: Baseline IPSS-M risk and allo-HCT had an independent impact on OS, while IWG 2023 defined cCR had an independent effect on OS only in non-transplanted MDS pts. While this retrospective analysis occurred at large academic centers with specific expertise in the management of MDS, our data may have an impact on clinical practice: (i) failure to achieve cCR on HMA therapy prior to transplant should not impact the decision to proceed to allo-HCT, (ii) upfront allo-HCT without prior HMA therapy might also be an option if the clinical situation and availability of donors allow, and (iii) allo-HCT should ideally be performed during the timeframe that is considered optimal as defined by pt age and baseline IPSS-M.

Background: Chromosomal rearrangements involving the KMT2A gene and mutations involving the nucleophosmin (NPM1) gene have been associated with response to menin inhibitors in multiple studies of acute myeloid leukemia (AML) patients characterized by these genetic alterations. Both alterations are more common in younger AML patients and those with NPM1 mutations historically perform better. However, the prevalence and outcomes of older (≥60 years) AML patients with these alterations who are treated with current therapies is less well understood. We present results from the Beat AML Master Trial (BAMT) that analyze the outcomes of this large, but less common subset of patients in an older AML population. Methods: Patients were consented and enrolled on this precision medicine-based Beat AML Master Trial (NCT03013998) from November 2016 to June 2024. Patients were included in this analysis if they harbor either the classic NPM1 mutation or a KMT2A rearrangement (over 10 different gene partners). Additionally, 2 patients with a NUP98 rearrangement were included with the KMT2A cohort as they are known to have similar biology in terms of menin dependence. These patients were treated with the following therapies: a sub-study specific targeted therapy for the dominant clone, venetoclax + hypomethylating agent (Ven/HMA), intensive chemotherapy (IC), alternative non-intensive therapy (NIT), or no therapy. Clinical/genetic characteristics and median overall survival (OS) were analyzed in each group separately. Overall survival (OS) was calculated from master consent and estimated using the Kaplan-Meier method. Results: Of 1096 AML patients enrolled on the BAMT, 246 patients had either an NPM1 (N=207, 18.9%) or KMT2A (N=39, 3.6%) genetic alteration. The baseline characteristics for the NPM1 cohort were median age 72 years (range: 60-92), 50% female, and ECOG performance status: 0-16%, 1-58%, 2-25% and 3-1%. Additional disease characteristics include treatment related AML at 11% and complex karyotype (≥3 abnormalities) at 3%. Median OS for the entire NPM1 cohort was 18.4 months (95% CI: 14.2-24.7). Patients were treated on a sub-study (35%), Ven/HMA (19%), IC (26%), NIT (8%) or no treatment (9%). Between treatment groups, median OS was 21 months (95% CI: 12.8-31.7) for those treated on a sub-study, 22 months (95% CI: 12.6-not reached (NR)) for Ven/HMA, 41.6 months (95% CI: 18.2-NR) for IC, and 6.3 months (95% CI: 1.3-23) for NIT, which was significantly different (p<0.0001). The baseline characteristics for the KMT2A cohort were median age 69 years (range: 60-88), 44% female, and ECOG performance status: 0-19%, 1-45%, 2-35% and 3-0%. Treatment related AML occurred in 23% of patients and complex karyotype in 31%. Median OS for the KMT2A cohort was 6.5 months (95% CI: 3.6-31.6). Patients were treated on a sub-study (38%), Ven/HMA (15%), IC (15%), NIT (15%), or no treatment (5%). Between treatment groups, median OS was 31.6 months (95% CI: 3.2-NR) for sub-study, 5.0 months (95% CI: 3.0-NR) for Ven/HMA, 12.7 months (95% CI: 4.9-NR) for IC, and 2.9 months (95% CI: 1.5-NR) for NIT, which was also significantly different (p<0.0001). Conclusions: In this cohort of older AML patients who possess NPM1 or KMT2A mutations, initial demographics and clinical characteristics upon presentation are as expected. Within each cohort and depending on the type of therapy received, there were interesting differences in survival. Median OS was the highest for the NPM1 cohort that received IC while the KMT2A cohort had the highest median OS when enrolled on a KMT2A targeted sub-study; a finding that supports precision-based medicine for this high-risk KMT2A group characterized by poor outcomes. As menin inhibitor combinations with induction chemotherapy or Ven/HMA move to the frontline setting, we anticipate seeing significant improvement in outcomes for AML patients in both of these genomic subsets. Further multivariable analysis will be performed to validate treatment effect on OS. Our analyses for these two cohorts also provide valuable outcome benchmarks for the design of future precision oncology studies that seek to improve survival in these subsets of older AML patients.

Abstract Although the 2022 European LeukemiaNet (ELN) acute myeloid leukemia (AML) risk classification reliably predicts outcomes in younger patients treated with intensive chemotherapy, it is unclear whether it applies to adults ≥60 years treated with lower-intensity treatment (LIT). We aimed to test the prognostic impact of ELN risk in patients with newly diagnosed (ND) AML aged ≥60 years given LIT and to further refine risk stratification for these patients. A total of 595 patients were included: 11% had favorable-, 11% intermediate-, and 78% had adverse-risk AML. ELN risk was prognostic for overall survival (OS) (P < .001) but did not stratify favorable- from intermediate-risk (P = .71). Within adverse-risk AML, the impact of additional molecular abnormalities was further evaluated. Multivariable analysis was performed on a training set (n = 316) and identified IDH2 mutation as an independent favorable prognostic factor, and KRAS, MLL2, and TP53 mutations as unfavorable (P < .05). A “mutation score” was calculated for each combination of these mutations, assigning adverse-risk patients to 2 risk groups: −1 to 0 points (“Beat-AML intermediate”) vs 1+ points (“Beat-AML adverse”). In the final refined risk classification, ELN favorable- and intermediate-risk were combined into a newly defined “Beat-AML favorable-risk” group, in addition to mutation scoring within the ELN adverse-risk group. This approach redefines risk for older patients with ND AML and proposes refined Beat-AML risk groups with improved discrimination for OS (2-year OS, 48% vs 33% vs 11%, respectively; P < .001), providing patients and providers additional information for treatment decision-making.