Median Leukemia-free Survival Research Articles

Haploidentical and matched unrelated donor allogeneic hematopoietic stem cell transplantation offer similar survival outcomes for acute leukemia.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has emerged as an effective approach for acute leukemia, primarily due to the inherent difficulty in finding human leukocyte antigen-matched unrelated donors (MUD). Nevertheless, it remains uncertain whether haplo-HSCT and MUD-HSCT can provide comparable outcomes in patients with acute leukemia. This study aimed to assess the overall survival (OS) and leukemia-free survival (LFS) outcomes between the MUD-HSCT and haplo-HSCT groups. This retrospective analysis encompassed adult patients with acute leukemia undergoing the initial allo-HSCT. Among these 85 patients, we stratified 33 patients into the MUD-HSCT group and 52 to the haplo-HSCT group. The primary outcomes were OS and LFS. The median OS was not reached in the haplo-HSCT group, while it reached 29.8 months in patients undergoing MUD-HSCT (p = .211). Likewise, the median LFS periods were 52.6 months in the haplo-HSCT group and 12.7 months in the MUD-HSCT group (p = .212). Importantly, neither the OS nor LFS showed substantial differences between the MUD-HSCT and haplo-HSCT groups. Furthermore, univariate analyses revealed that haplo-HSCT did not demonstrate a significantly higher risk of worse LFS (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.38-1.25; p = .216) or OS (HR, 0.67; 95% CI, 0.36-1.26; p = .214) than MUD-HSCT. Notably, a high European Group for Blood and Marrow Transplantation risk score (HR, 1.44; 95% CI, 1.10-1.87; p = .007) and non-complete remission (HR, 2.48; 95% CI, 1.17-5.23; p = .017) were significantly correlated with worse OS. Haplo-HSCT may serve as an alternative to MUD-HSCT for the treatment of acute leukemia, offering similar survival outcomes.

Abstract 6208: Characterization of molecular evolution in myelodysplastic neoplasms

Abstract Myelodysplastic neoplasms (MDS) are hematopoietic stem cell disorders. The IPSS-Mol model, a scoring system that combines molecular and clinical features to stratify MDS patients, can identify individuals at high-risk of developing Acute Myeloid Leukemia (AML), enabling the targeted application of disease-modifying therapies. However, the molecular evolutionary patterns in MDS and their impact on Overall Survival (OS) and Leukemia-Free Survival (LFS) remain unexplored. Shifting from conventional static mutational analyses used by IPSS-Mol to a dynamic evolutionary approach, we employed the ASCETIC framework to analyze data from the IPSS-Mol Database (3,323 patients, 152 genes) and understand the dynamics of MDS progression. According to ASCETIC, genes related to DNA methylation displayed low ranks, indicating their tendency to manifest early in the progression of the disease. In contrast, genes associated with cellular signaling typically appeared in the later stages of tumor progression, while genes involved in RNA splicing exhibited intermediate ranks.Regarding molecular evolution in MDS, ASCETIC identified five clusters, each characterized by distinct evolutionary signatures and significantly different OS and LFS rates (p < 0.001). The median OS for the C1, C2, C3, C4, and C5 clusters were 79.3, 64.1, 28.9, 16.2, and 14.8 months, respectively. Subsequently, we compared ASCETIC's clusters with the different risk groups defined by the IPSS-Mol score. Among the 1158 patients initially classified as V-Low/M-Low risk by IPSS-Mol, ASCETIC identified 55 patients placed in C4 and C5. These patients exhibited lower OS (p = 0.005) and LFS (p = 0.02). Conversely, among the 905 IPSS-Mol M-High/V-High risk patients, ASCETIC identified 468 patients (51.7%) classified as low risk (C1-C2-C3), who were associated with longer median OS and LFS (p < 0.001). The differences between conventional mutational analyses and our evolutionary approach primarily, but not exclusively, arise from the evaluation of TP53 mutations and ASXL1. In the IPSS-Mol model, a higher risk is conferred if multi-hit TP53 alterations occur or in the presence of ASXL1 mutations.Conversely, ASCETIC assesses the impact of mutations differently. It considers not only the Variant Allele Frequencies of individual- and/or co-mutations but also the evolutionary trajectories that lead to TP53 and/or ASXL1. This approach results in different risk weights assigned to each evolutionary trajectory.Lastly, we identified patients with NPM1 mutations, classified as MDS patients in the original dataset but now categorized as AML according to 2022-WHO. Within this high-risk context, ASCETIC differentiated between patients with shorter and longer Overall Survival (OS) (p < 0.001).Our study reveals the influence of evolution on MDS prognosis, offering insights into the integration of the ASCETIC framework with the IPSS-Mol. Validation on external cohort is ongoing. Citation Format: Ivan Civettini, Valentina Crippa, Federica Malighetti, Matteo Villa, Andrea Aroldi, Fabrizio Cavalca, Alex Graudenzi, Lorenza Maria Borin, Luca Mologni, Rocco Piazza, Carlo Gambacorti-Passerini, Daniele Ramazzotti. Characterization of molecular evolution in myelodysplastic neoplasms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6208.

The clinical, molecular, and prognostic features of the 2022 WHO and ICC classification systems for myelodysplastic neoplasms

Myelodysplastic neoplasms (MDS) are clonal disorders of bone marrow failure exhibiting a variable risk of progression to acute myeloid leukemia. MDS exhibit certain prognostic genetic or cytogenetic abnormalities, an observation that has led to both the pathologic reclassification of MDS in the 2022 World Health Organization (WHO) and International Consensus Classification (ICC) systems, as well as to an updated prognostic schema, the Molecular International Prognostic Scoring System (IPSS-M). This single-institution study characterized the molecular patterns and clinical outcomes associated with the 2022 WHO and ICC classification schemas to assess their clinical utility. Strikingly, with the exception of one individual, all 210 patients in our cohort were classified into analogous categories by the two pathologic/diagnostic schemas. Most patients (70%) were classified morphologically while the remaining 30% had genetically classified disease by both criteria. Prognostic risk, as assessed by the IPSS-M score was highest in patients with MDS with biallelic/multi-hit TP53 mutations and lowest in pts with MDS-SF3B1. Median leukemia-free survival (LFS) was shortest for those with MDS with biallelic/multi-hit TP53 (0.7 years) and longest for those with MDS with low blasts (LFS not reached). These data demonstrate the clear ability of the 2022 WHO and ICC classifications to organize MDS patients into distinct prognostic risk groups and further show that both classification systems share more similarities than differences. Incorporation of the IPSS-M and IPSS-R features provide additive prognostic and survival components to both the WHO and ICC classifications, which together enhance their utility for evaluating and treating MDS patients.

The Significance of Variant Allele Frequency in SF3B1 Mutated Myelodysplastic Neoplasms/Syndromes

Introduction: Recent iterations of the World Health Organization (WHO) and international consensus classification (ICC) guidelines for myelodysplastic neoplasms (MDS) refined disease defining characteristics through incorporation of morphologic and genetic criteria. Despite these welcome updates, discrepancies between the WHO and ICC remain, particularly with respect to variant allele frequency (VAF) threshold in disease defining mutations such as SF3B1 and TP53. We evaluated patients with SF3B1-mutated MDS, a specific molecular class of MDS in both classification schemes , providing additional biologic and survival information to inform both diagnosis and prognosis. Methods: We queried the International Working Group for Prognosis in MDS (IWG-PM) cohort of adult (age ≥ 18 years) patients (pts) with MDS (N= 3,323; Bernard et al. NEJM Evidence 2022) for baseline clinical demographic, cytogenetic and molecular information, and clinical outcomes. SF3B1 VAF was assessed using targeted next generation sequencing. Demographics were analyzed using descriptive statistics. Between group differences were assessed using the Wilcoxon rank-sum test or Fisher's exact test as appropriate. Time to event endpoints were analyzed using the log-rank method. Multivariate analysis utilized cox proportional hazards regression. Results: We identified 447 (14%) pts met WHO 5th criteria for MDS with low blasts and SF3B1 mutation. Among these, 30 (7%) of pts had a SF3B1 VAF < 10% ( SF3B1low;currently classified as MDS, not otherwise specified by ICC) while 93% (N=417/447) had SF3B1 VAF of ≥ 10% ( SF3B1high). Median VAF in pts with SF3B1low vs. SF3B1high was 6% (range: 2.2-9.9%) vs. 37% (range: 10.9-54.1%). Pts with SF3B1low vs. SF3B1high were older (median age 79 vs. 74, p=0.010), and had lower median platelet (185 x10 9/L vs. 264 x10 9/L, p < 0.001) and white blood cell levels (3.94 x10 9/L vs. 5.46 x10 9/L , p < 0.001). The median number of mutations other than SF3B1 in SF3B1low and SF3B1high was 2 (range: 0-5 vs. 0-8, p=0.42), and SF3B1 was the sole genetic alteration in 10% vs. 20%, respectively (OR=2.2, p=0.24). Common SF3B1 variants in SF3B1low vs. SF3B1 high included p.K666 (27% vs. 10%, OR: 0.31, p=0.01) and p.K700 (50% vs. 59%, OR: 1.42, p=0.44). In pts with SF3B1low, single-hit mutations in TP53 (13% vs. 3%, OR: 0.21, p=0.021), SRSF2 (10% vs. 3%, OR: 0.25, p=0.06), and RUNX1 (7% vs. 4%, OR: 0.60, p=0.37) were more frequent (Fig. A). Other co-mutations had similar frequencies in SF3B1low vs. SF3B1high MDS: TET2 (33% vs. 42%, OR: 1.45, p=0.44), DNMT3A (23% vs. 27%, OR 1.22, p=0.83), ASXL1 (17% vs. 13%, OR: 0.71, p=0.57).The distribution of SF3B1 VAF, and observed patterns of co-mutations did not differ by sample type (peripheral blood or bone marrow). More pts with SF3B1low vs. SF3B1high (76% vs. 46%, p: 0.0011) had a subclonal SF3B1 mutation compared with other co-occurring mutations. In the 213 (48%) pts with subclonal SF3B1, the most frequent dominant mutations included TET2 (35%, N=75), DNMT3A (21%, N=45), and ASXL1 (4%, N=8). Among the top co-mutations in SF3B1low vs. SF3B1high, SF3B1low was more frequently subclonal to TP53 (50% vs. 0%, p=0.04), SRSF2 (33% vs. 0%, p=0.2), and RUNX1 (50% vs. 0%, p=0.1). As anticipated, SF3B1high cases were enriched for very-low/low risk IPSS-M subtypes (78% vs. 43%, OR: 2.9, p=0.011) compared to SF3B1low cases which had an increased frequency of moderate IPSS-M subtypes (30% vs. 14%, OR: 0.39, p=0.03; Fig.B). Median leukemia free survival (LFS; 5 vs. 6 years, p=0.10) was not significantly different between pts with SF3B1low vs. SF3B1high MDS. Median overall survival (OS; 5 vs. 6.2 years, p=0.04) was significantly shorter in pts with SF3B1low, however after adjusting for SF3B1 VAF, age, and IPSS-M score, only age (HR: 1.05 95% CI: 1.03-1.07, p < 0.0001), and increasing IPSS-M score (HR: 2.60 95% CI: 2.10-3.20, p< 0.0001) significantly associated with OS. Conclusion: Patients with MDS with SF3B1-mutation VAF < 10% are older and have an increased frequency of other clonally dominant co-mutations in adverse risk genes (i.e., TP53, SRSF2, RUNX1). Despite more adverse disease biology, LFS and OS were similar between pts with SF3B1low vs. SF3B1high with respect to SF3B1 VAF after accounting for age and IPSS-M score. Future diagnostic and prognostic schema could account for differences in SF3B1lowdisease biology through use of comprehensive prognostic tools such as the IPSS-M score.

Analysis of CD58 As a Predictive Marker of Morphologic Response to Inotuzumab Ozogamicin in Patients with B-Cell Acute Lymphoblastic Leukemia

BACKGROUND Clinical outcomes for B-cell Acute Lymphoblastic Leukemia (B-ALL) have significantly improved in the last decade, owing to the introduction of newer agents such as inotuzumab ozogamicin (INO) and blinatumomab. Both of these antibody-based therapies are effective in adults with relapsed or refractory (R/R) B-ALL and have shown promising results in the frontline setting as well. Given the utility of these therapies, there have been efforts to identify predictive markers for these treatments in B-ALL patients. Recently, CD58 was identified as a modulator of response to blinatumomab due to its role as a CD2 ligand in T-cell activation (Li et al. Sci Adv 2022). This costimulatory relationship between CD58 and CD2 has also been linked to Natural Killer cell mediated lysis, which has been described as a mechanism of action of INO (Fu et al. Signal Transduct Target Ther 2022; Huntington et al. Nat Rev Cancer 2020). In this study, we evaluated the correlation of CD58 expression with achievement of morphologic Complete Remission (CR) or Complete Remission with incomplete blood count recovery (CRi) after treatment with INO. METHODS Retrospective chart review was performed to identify patients in our institution's B-ALL database who received INO between 09/15/2011 and 03/10/2023 with blood or bone marrow samples available for flow cytometry analysis prior to INO infusion. Because all patients had measurable CD58 expression by flow cytometry, mean fluorescence intensity (MFI) was used instead of percent positivity to perform a simple logistic regression analysis to evaluate the relationship between CD58 MFI and achievement of CR/CRi after treatment with INO. We then calculated the odds of achieving CR/CRi by age, molecular risk at diagnosis, and R/R disease status. Two patients lacked diagnostic cytogenetic data. Molecular risk stratification and assessment of morphologic response were performed according to National Comprehensive Cancer Network (NCCN) guidelines. To account CD58 MFI outliers, we then confirmed our results by comparing response rates between patients with a CD58 MFI above our median (CD58 MFI-high) to patients with a CD58 MFI below our median (CD58 MFI-low) using Fisher's exact test. RESULTS We found 34 patients who met our criteria for analysis, 2 of which had previously received INO (Table1). Median Overall Survival (OS) was 21.5 months (range, 1-58) with a median leukemia-free survival (LFS) of 13.5 months (range, 1-52). Response rates after INO were high, including 28 patients (82.4%) achieving CR, 30 patients (88.2%) achieving CR/CRi, and 27 patients (79.4%) achieving Measurable Residual Disease (MRD) negativity. Both patients with a history of prior treatment with INO attained CR with MRD negativity. The chi-square test statistic for our simple logistic regression model was not statistically significant (Figure1, p=0.915). The logistic regression coefficient showed no statistically significant association between CD58 MFI and CR/CRi rates after treatment with INO ( p=0.913). Our model predicted an 88.6% probability of achieving CR/CRi for a CD58 MFI of 8,727.97 (Q1), 88.4% for 11,719.88 (Q2), 88.0% for 19,622.85 (Q3), and 85.7% for 55,217.74 (Q4). There was no statistically significant difference in the odds of achieving CR/CRi in patients with poor molecular risk at diagnosis (OR=0.06, 95% CI [0.01, 1.22]), age >35 years (OR=2.75, 95% CI [0.33, 22.9]), or R/R disease (OR=0.98, 95% CI [0.01, 1.97]). When comparing response rates between CD58 MFI-high and CD58 MFI-low patients, each group contained 15 patients that achieved CR/CRi and 2 patients with refractory disease. This confirmed an equal response rate to INO between CD58 MFI-high and CD58 MFI-low patients ( p=1.000). CONCLUSION Overall, we did not find a statistically significant correlation between CD58 MFI and achievement of CR/CRi. Our study is limited by our small sample size, single-center location, and retrospective design. However, it is important to note the high rates of CR/CRi that were seen, regardless of the intensity of CD58 expression. Further work is needed to evaluate the role of CD58 as a predictive marker for other therapies in B-ALL. These data suggest that INO is likely to remain an effective option for these patients, regardless of the intensity of CD58 expression.

Efficacy, Safety, and Survival Findings after Long-Term Follow-up from ZGJAK002, a Phase 2 Study Comparing Jaktinib 100 Mg Twice Daily with 200 Mg Once Daily for Myelofibrosis (MF)

Background: Jaktinib, a novel Janus kinase (JAK) and ACVR1 inhibitor, demonstrated promising clinical benefit with good tolerability, not only efficiently shrinking the spleen and reducing symptom burdens, but also improving anemia, in JAK-inhibitor naïve, ruxolitinib-intolerant or -resistant MF patients. We conducted a phase 2 study (the ZGJAK002 trial) to evaluate the effectiveness and safety of jaktinib at doses of 100 mg BID and 200 mg QD in JAK-inhibitor naïve patients with intermediate or high risk MF. Herein we present long-term data with a median follow-up time of 30.7 months. Methods: Patients who completed the 24 weeks of study treatment, tolerated the drug well, and had evidence of clinically significant improvement were allowed to enter an extension phase. Dose modifications were permitted according to the platelet count and neutrophil count. Duration of spleen response (from the first spleen volume reduction of ≥35% [SVR35] to an increase of 25% or more from the nadir), overall survival (OS), and leukemia-free survival (LFS) were evaluated in an intent-to-treat analysis using a Cox proportional hazard model that estimated the treatment effect. Results: A total of 118 patients were enrolled and treated with either jaktinib 100 mg BID (n=66) or 200 mg QD (n=52). The majority of patients remained on treatment after 48 weeks (100 mg BID group: 74.2%; 200 mg QD group: 65.4%). At the data cutoff of June 30, 2022, treatment was continued in 35 (29.7%) patients (30.3% in BID; 28.8% in QD). The best spleen response, defined as SVR35 at any time, was achieved by 59.3% (95% confidence interval [CI]: 49.9%-68.3%) of patients. The 100 mg BID group demonstrated a greater best spleen response (69.7% [95% CI: 57.1%-80.4%]) compared to the 200 mg QD group (46.2% [95% CI: 32.2%-60.5%]). The median maximum reduction from baseline in spleen volume was 49.7%. The median duration of spleen response was not reached, with 51.9% (95% CI: 36.0%-65.7%) of patients from 100 mg BID and 66.5% (95% CI: 41.4%-82.8%) from 200 mg QD maintaining a spleen response for over 108 weeks (Figure 1). The proportion of patients who achieved an improvement of ≥50% in the TSS (TSS50) was 69.6% (95% CI: 55.9%-81.2%) at week 24 and 74.2% (95% CI: 55.4%-88.1%) at week 108 in the 100 mg BID group. The proportion of patients who achieved TSS50 was 57.5% (95% CI: 40.9%-73.0%) at week 24 and 66.7% (95% CI: 44.7%-84.4%) at week 108 in the 200 mg QD group. As of the data cutoff, 25 (21.2%) deaths were reported (12 [18.2%] of 66 in the 100 mg BID group and 13 [25.0%] of 52 patients in the 200 mg QD group). Median OS was not reached, with 12, 24, and 36-month survival rates of 92.3%, 85.8%, and 78.2% in the 100 mg BID and 92.3%, 78.0%, and 73.6% in 200 mg QD groups. Median LFS was not reached, with 12, 24, and 36-month LFS rates of 94.8%, 90.6%, and 84.1% in the 100 mg BID and 95.5%, 85.7%, and 85.7% in 200 mg QD groups. The 100 mg BID induced more increase from baseline in hemoglobin concentration over 144 weeks with a range of 2.18-10.17 g/L compared to -1.74-1.96 g/L with 200 mg QD. The median (range) duration of jaktinib exposure was 672.0 (14-1262) days in the 100 mg BID group and 588.5 (42-1175) days in the 200 mg QD group. The median relative dose intensity for jaktinib was 97.5% (98.1% in BID; 96.3% in QD). There was no unexpected increased incidence of adverse events (AEs) with longer exposure. The most common grade ≥3 adverse drug reactions were anemia (15.2% vs. 21.2%), thrombocytopenia (15.2% vs. 11.5%), and infectious pneumonia (10.6% vs. 1.9%) in the 100 mg BID and 200 mg QD groups, respectively. Notably, infectious pneumonia (10.6%), thrombocytopenia (4.5%), and peripheral neuropathy (3.0%) were the most common drug-related serious AEs. AEs leading to treatment discontinuation occurred in 14 patients (11.9%), with higher rate in the 100 mg BID group compared to the 200 mg QD group (15.2% vs. 7.7%). AEs resulted in death in seven (5.9%) patients, with similar rates in both groups (6.1% in BID; 5.8% in QD). Conclusions: With over 30-month follow-up, jaktinib at doses of 100 mg BID and 200 mg QD demonstrated durable high effective rates and improved survival rates without new safety issue. The long-term data further supports the recommendation of 100 mg BID over 200 mg QD administration. It also concluded that jaktinib remains the treatment strategy that offers excellent chances for improving survival in MF patients.

ASXL1/ TET2 Genotype-Based Risk Stratification Outperforms ASXL1 Mutational Impact and Is Independent of Mutant Variant Allele Fractions (VAF) in CMML

Introduction Truncating ASXL1 mutations in chronic myelomonocytic leukemia (CMML) are associated with inferior overall survival (OS) and leukemia free survival (LFS). Conversely, loss-of-function mutations in TET2 are associated with better outcomes, with the ASXL1wt/ TET2mut genotype being associated with the best OS and LFS-rates (Coltro G, et al. Leukemia. 2020). Contemporary CMML prognostic scoring systems - such as the Mayo Molecular Model (MMM; Patnaik MM, et al. Leukemia. 2014) and the CPSS-Molecular Model (CMM; Elena C, et al. Blood. 2016) - do not consider concomitant ASXL1/ TET2 mutational status or mutational VAF. We hypothesized that the ASXL1/ TET2 genotype would better risk stratify patients in comparison to ASXL1 mutations alone, and that this effect would be proportional to the underlying mutational VAF. Methods After IRB approval, we compiled a large (n = 888), molecularly annotated database of CMML patients seen at two US medical centers (Mayo Clinic and MD Anderson) via retrospective chart review. All statistical analyses considered the clinical and laboratory parameters obtained at the time of presentation to the respective institution. Categorical variables were compared by Fisher exact or Pearson χ 2 tests and continuous variables by Mann-Whitney U tests. Univariate and multivariate analyses were performed using Cox proportional hazards regression models. Survival was assessed via the Kaplan-Meier method. P-values < 0.05 were considered significant. All statistical calculations were performed using the BlueSky Statistics (v10.3.1) interface for R. Results The median age of the cohort was 71 years (range 20 - 94), 67% were male, 46% had proliferative CMML (pCMML), and 19% had CMML-2. The distribution of low, intermediate-1, intermediate-2, and high-risk patients was 15%, 11%, 32%, and 42% by the MMM and 9%, 23%, 40%, and 28% by the CMM, respectively. The most frequently mutated genes were ASXL1 (45%), TET2 (43%), SRSF2 (41%), and RUNX1 (17%), while 40% harbored at least one RAS pathway mutation ( NRAS 16%, CBL 15%, KRAS 8%, PTPN11 4%, FLT3 2%). The median OS and LFS of the entire cohort were 31.8 months (95% CI 28.4 - 33.5 months) and 28.4 months (95% CI 24.6 - 32.1 months), respectively. Patients were stratified into ASXL1wt/ TET2wt (28%), ASXL1mut/ TET2wt (29%), ASXL1wt/ TET2mut (26%), and ASXL1mut/ TET2mut (17%) genotypes. Those with isolated TET2 mutations had the longest median OS (53.6 months; p < 0.02 for all comparisons) whereas those with isolated ASXL1 mutations had the shortest median OS (20.9 months; p < 0.04 for all comparisons); mutations in neither or both genes performed similarly (p = 0.9224; Figure 1A). The same trend was seen for LFS. We further hypothesized that the ASXL1 or TET2 mutation VAF would be more predictive of outcomes than a binary metric. The respective median VAFs were 37% (quartiles 28% - 45%) and 45% (quartiles 40% - 49%). When treated as a continuous variable, however, there was no correlation between either VAF and OS or LFS by both Pearson linear regression and Cox proportional hazard modeling. Unlike the overall cohort, the ASXL1/ TET2 genotypes did not further stratify patients with pCMML, CMML-2, or those considered high risk by the CMM in Kaplan-Meier analyses, suggesting that the high-risk features inherent in these subgroups outweigh the benefits of the TET2 mutation. In contrast, patients considered high-risk by the MMM were further stratified by the ASXL1/ TET2 genotypes. Incorporating TET2 mutations into the MMM as a protective factor (worth -1.5 points) improved detection of low- (≤ 1 point) and high-risk (≥ 4 points) patients, while intermediate-1 and intermediate-2 coalesced into a single intermediate risk category ( Figure 1B). A similar phenomenon was observed when TET2 was incorporated into the CMM (worth -1 point, yielding low- (0 points), intermediate- (1-2 points), and high-risk (≥ 3 points) groups with median OS of 83 months (95% CI 66.2 - 104.2), 34.3 months (95% CI 31.6 - 38.7), and 17.7 months (95% CI 15.7 - 20.2), respectively. Conclusions Truncating and hypomorphic TET2 mutations are associated with better outcomes in CMML, with the ASXL1mut/ TET2wt genotype being associated with improved risk stratification in comparison to ASXL1 mutational status alone. Counterintuitively, in our data set, this stratification was not impacted by mutational VAF, supporting binary mutational assessments in prognostic models.

Validation of ELN 2022 Risk Classification in Patients Diagnosed with AML Undergoing Allogeneic Hematopoietic Cell Transplantation

Background: In 2022, the European LeukemiaNet (ELN) updated their guidelines (Döhner H et al., Blood 2022) for risk allocation of patients with acute myeloid leukemia (AML) based on essential genetic features at diagnosis as defined in the newest classifications (Arber D et al., Blood 2022, Khoury JD et al., Leukemia 2022). Methods: Retrospective analysis of the 147 consecutive patients diagnosed with AML and available genetic information who underwent alloHCT in a complete morphological response (CR) between 2011 and 2021 in a single institution (HCB). Data was collected retrospectively and updated in July 2023. G-banding karyotype, FISH, qualitative and quantitative PCR and targeted Next Generation Sequencing were assessed at diagnosis to classify patients according to ELN 2022 risk classification. Our primary goal was to validate the ELN 2022 risk classification in patients undergoing alloHCT analyzing overall survival (OS). Secondary objectives were analyzing leukemia-free survival (LFS), 24-month cumulative incidence of relapse (CIR) and in the different molecular subgroups within the ELN2022 risk groups. Results: The main patient, disease-related and transplant characteristics are displayed in Figure 1. Overall, the median age was 52 years (range 18-70), 53.7% of the patients males, with 88% of the patients undergoing alloHCT in CR1. Twenty-two patients could not be classified through NGS assessment between 2011 and 2016 and included in the intermediate risk category due to normal karyotype and wildtype recurrent abnormalities measured by PCR. Patients in the adverse-risk group were older (p <0.001) and underwent alloHCT less often with undetectable measurable residual disease (p = 0.006). Moreover, patients in the favorable or intermediate risk group underwent alloHCT more often in CR2 or CR3 (p = 0.02). In addition, alloHCT characteristics were similar for all the patients included. With a 67-month median follow-up for LFS (95CI: 55-76), the median OS and LFS in patients classified into the favorable and intermediate risk groups were not reached (5-year OS and LFS rate in favorable risk group: 81% (95CI: 73-89) and 72% (95CI: 63-81). 5-year OS and LFS rate in intermediate risk group: 62% (95CI: 56-68) and 64% (95CI: 58-70). Patients included in the adverse risk group had an OS and LFS of 23.7 months (15.3-NR, p <0.001 between intermediate and adverse risk. Figure 1B) and 15.2 months (5.79-NR, p=0.015) respectively, with a significant lower 5-year OS rate (40%, 95CI: 34-46), LFS rate (38%, 95CI: 32-44) and a higher CIR (18% in the favorable risk group (95%CI: 11-26) vs. 20% in the intermediate risk group (95%CI: 18-23) vs. 40% in the adverse risk group (95%CI: 38-44), p = 0.024). Based on these results, a subanalysis was conducted in the patients classified into the adverse group. Those patients diagnosed with complex karyotype, inv(3), t(3;3), del(17p) and/or TP53 mutated were reassessed into a new risk category group called: Adverse-Plus (AdvP).No different baseline characteristics between the AdvP patients and the other subgroups were found. AdvP patients presented a shorter OS (NR in the rest of subgroups vs. 8.73 months in AdvP, p < 0.001 for AdvP vs. adverse risk. Figure 1C), LFS (NR in the rest of subgroups vs. 5.2 months, p < 0.001), and a higher CIR (62.5% in the AdvP group, p <0.001 between adverse risk and AdvP). Interestingly, using this four-group classification including AdvP, the other risk groups presented similar OS, LFS, and CIR without statistical differences in between them Summary/Conclussion: ELN2022 risk classification discriminates properly accurate in patients undergoing alloHCT. Reclassifying AML adverse risk patients diagnosed with complex karyotype, inv(3), t(3;3), del(17p) and/or TP53 mutated in a different subgroup should be considered due to a much worse prognosis after alloHCT, although it remains mandatory in first complete response.

Clinical Outcomes and Mutational Profile Associated with Dysmyelopoiesis in Chronic Myelomonocytic Leukemia

Chronic myelomonocytic leukemia (CMML) is defined by absolute (≥ 0.5 x10 9/L) and relative (≥ 10%) monocytosis in peripheral blood. Presence of significant dysplasia in any of the three myeloid series, in particular dysgranulopoiesis, is an almost constant finding in CMML. In the absence of a clonal marker, a scenario very unlikely with the advent of next-generation sequencing (NGS), significant myeloid dysplasia becomes a crucial criterion for establishing the diagnosis. Although bone marrow dysplasia has demonstrated independent prognostic value in MDS, its significance in relation to CMML has never been assessed. The main interest of our work was to evaluate the genomic determinants of dysplasia and to assess its prognostic impact. We analyzed a series of 240 patients with CMML with clinical, morphological, immunophenotypic, cytogenetic and molecular information. Patients were diagnosed following WHO and ICC 2022 recommendations. As a novelty with respect to previous WHO classifications, the new definition of CMML includes those patients previously categorized as oligomonocytic CMML (OM-CMML). That is, myelodysplastic neoplasms (MDS) or unclassifiable myelodysplastic/myeloproliferative neoplasms with relative monocytosis and a monocyte count of 0.5 × 10 9/L to <1 × 10 9/L. A total of 167 (71%) patients were diagnosed with CMML-1 and 67 (29%) with CMML-2. Likewise, 193 (80%) patients were diagnosed with dysplastic CMML, 55 of whom would meet criteria for OM-CMML, and 47 (20%) were diagnosed with proliferative CMML. We assessed associations between dysmyelopoiesis and gene mutations by Spearman's rank correlation coefficient. Dysgranulopoiesis showed a significant positive correlation with NRAS, TET2 and ZRSR2 mutations; while a significant negative correlation with SETBP1 was observed. Dysmegakaryopoiesis showed a significant positive correlation with ASXL1 and TP53. Dyserythropoiesis showed a significant positive correlation with DNMT3A and SF3B1. The heatmap and matrix showing these correlations, as well as the differences in the degree of dysmyelopoiesis among these specific mutations are depicted in Figure 1-A & 1-B. Later, we wanted to assess the prognostic impact of dysgranulopoiesis, dyserythropoiesis and dysmegakaryopoiesis in terms of overall survival (OS) and leukemia-free survival (LFS) in our series. By applying the MaxStat package in R, it allowed us to detect the best cut-off points for dysgranulopoiesis (>75%) and dysmegakaryopoiesis (>20%) to separate our series into two groups with significantly different outcomes (Figure 1-C). We were unable to detect a significant cut-off point for dyserythropoiesis and the presence of multilineage dysplasia also showed no prognostic impact. CMML patients with dysgranulopoiesis above 75% showed a significant shorter median OS (34.4 vs 67.8 months; Hazard Ratio (HR): 1,99 [1.24-3.19]; P=0.0036) and LFS (33.4 vs 66.6 months; HR: 1,87 [1.17-3]; P=0.008). Likewise, patients with dysmegakaryopoiesis above 20% also showed a significant shorter median OS (30.2 vs 67.1 months; HR: 2.52 [1.63-3.88]; P<0.0001) and LFS (30.4 vs 66.6 months; HR: 2.76 [1.78-4.28]; P<0.0001). Remarkably, dysmegakaryopoiesis above 20% and dysgranulopoiesis above 75% were identified as independent prognostic factors for both OS and LFS after adjustment by multivariable Cox regression analyses by CMML-specific prognostic scoring system (CPSS) and Mayo Prognostic Model. Furthermore, the addition of dysmegakaryopoiesis above 20% and dysgranulopoiesis above 75% to these prognostic indices improved their prognostic accuracy in terms of OS as assessed by a C-index for right-censored data (Figure 1-C). In conclusion, our study has allowed us to detect mutations in genes related to dysmyelopoiesis. In addition, both dysgranulopoiesis and dysmegakaryopoiesis have demonstrated a negative prognostic impact on the survival of patients in our series that was not captured by the CPSS and Mayo prognostic model. Their worse prognosis could be partially justified by their association with poor prognostic mutations (e.g. NRAS, ASXL1, TP53), which allows us to visualize them as a good surrogate of poor prognostic molecular profiles.

Clinical Characteristics and Outcomes of Therapy-Related Chronic Myelomonocytic Leukemia: Analysis of a Large Cohort

Introduction: Therapy-related myeloid neoplasms are associated with a previous exposure to cytotoxic agents or ionizing radiation, and account for 10-20% of all myeloid neoplasms. They are associated with a worse outcome, usually with high risk genetic abnormalities and poor response to therapies. Chronic myelomonocytic leukemia (CMML) is a rare myeloid neoplasm with persistent monocytosis, bone marrow dysplasia and an inherent risk of acute myeloid leukemia (AML) transformation. Due to its rarity, it is difficult to establish the specific impact of previous therapy in CMML. We previously reported the characteristics and outcomes of patients with therapy-related CMML (tCMML). Herein we report an update, including molecular characteristics, being the largest tCMML cohort reported to date. Methods: We retrospective evaluated a cohort of patients diagnosed with CMML from 2005 to 2022. Data regarding previous exposure to treatment was captured and tCMML diagnosis was established for patients with a documented prior history of radiation therapy or cytotoxic chemotherapy due to an antecedent malignancy prior to the diagnosis of CMML. Those non-tCMML were defined as de novo CMML (dnCMML). Overall survival (OS) was calculated from diagnosis to death, and leukemia-free survival (LFS) was calculated from diagnosis to death or AML transformation. Results: A total of 532 patients with CMML were included in the study, of whom 71 (13%) were tCMML. When comparing tCMML with dnCMML, there were no differences in median age (73 vs 70 years old) or sex (67% vs 69% male). No differences were noted in white blood cell count, absolute monocyte count, hemoglobin or platelet count. According to the WHO 2016 classification, 38% vs 44% were CMML-0, 40% vs 36% were CMML-1, and 22% vs 20% were CMML-2, for patients with dnCMML and tCMML, respectively. According to the FAB classification, 42% vs 52% were dysplastic and 58% vs 49% were proliferative, for patients with dnCMML and tCMML, respectively. Chromosome 7 abnormalities where more common among tCMML compared to dnCMML (14% vs 4%, p=0.006), with no differences in frequency of complex karyotype (8% vs 3%, p=0.1). In tCMML patients, 35% received only radiotherapy, 31% only chemotherapy and 34% both. In patients that received chemotherapy, the most common therapies were alkylating agents (45%), agents targeting microtubules (37%) and antimetabolite agents (35%). The median latency from therapy to tCMML was 6.5 years (range, 0.1-24). Most common neoplasms prior to the diagnosis of tCMML were prostate (25%), lymphoma (23%) and breast cancer (14%). Most frequently detected mutations at diagnosis were TET2 (55% vs 61%, p=0.5), ASXL1 (44% vs 53%, p=0.3), and SRSF2 (43% vs 30%, p=0.1), in patients with dnCMML and tCMML, respectively. Patients with tCMML had a lower incidence of NRAS (22% vs 6%, p=0.007) and CBL (18% vs 5%, p=0.04) mutations compared to dnCMML, but these mutations were present at a higher median VAF among patients with tCMML (48% vs 18% [p=0.04] for NRAS and 91% vs 20% [p=0.02] for CBL) (Figure 1). TP53 mutations were more frequent in the tCMML although differences were not significant (12% vs 4%, p=0.06). Among all patients, 352 patients received treatment and were evaluable for response (305 patients with dnCMML and 47 patients with tCMML). More than 90% of patients received an hypomethylating agent-based therapy, with an ORR of 59% for dnCMML and 60% for tCMML. The median follow-up was 58 months, and the median OS and LFS for the entire cohort were 36 and 29 months, respectively. No differences in OS (36 vs 35 months, p=0.3) or LFS (29 vs 28 months, p=0.8) were observed between dnCMML and tCMML, However, when comparing by risk groups according to CPSS-Mol, patients with tCMML classified as intermediate-1 (Int-1) risk had a significant lower OS (38 vs 88 months, p=0.02) and LFS (38 vs 85 months, p=0.03), compared to Int-1 dnCMML (Figure 2). In a multivariate model for OS including CPSS-mol, tCMML stratified by type of therapy and age, patients with tCMML with a previous exposure to chemotherapy had a hazard ratio of 1.76 (1.07-2.89, p=0.03). Conclusion: Patients with tCMML have a higher proportion of chromosome 7 abnormalities and a lower incidence of NRAS and CBL mutations. Although responses to HMA were similar, patients with tCMML with a previous exposure to chemotherapy are associated with a lower survival, especially patients classified as CPSS-Mol intermediate-1.

TP53 Y220C Mutations in Patients with Myeloid Malignancies

Background: TP53 gene mutations lead to inactivation of the protein p53, causing genome instability, oncogenesis, and treatment resistance conferring an unfavorable prognosis. TP53 Y220C missense mutations in exon 6 (p.659A>G) are described as a frequent ‘hot spot’ mutation in solid tumors. A novel Y220C-targeted small molecule (PC14586) has shown preliminary efficacy and safety in patients with solid tumors (Dumbrava, E., ASCO 2022). No data has been reported about TP53 Y220C in hematologic malignancies to date. We set out to evaluate the clinicopathologic characteristics of TP53 Y220C in hematologic malignancies and particularly, myeloid neoplasms. Methods: We identified all patients with hematologic neoplasms with TP53 Y220C mutations at University of Texas MD Anderson Cancer Center and Memorial Sloan-Kettering Cancer Center, detected by standard next generation sequencing assays, and focused on patients with myeloid malignancies; summarizing the patient characteristics, disease features and outcomes for patients with this specific TP53 mutation. Overall survival (OS) was assessed by the Kaplan-Meier method from date of diagnosis to date of death from any cause or date of last follow-up. Leukemia-free survival (LFS) was calculated from time to diagnosis of TP53 Y220C mutated myelodysplastic syndrome (MDS) to date of transformation to acute myeloid leukemia (AML) or death. Survival analysis was conducted only for newly diagnosed patients with available follow-up data. Results: We identified 143 patients (pts) with hematologic malignancies harboring a TP53 Y220C mutation. MDS and AML were the most frequent diagnoses (MDS, n=66; AML, n=48). Median age was 69 years (range, 32-92) and 56% of patients were male (Table 1). We then analyzed in more detail patients with MNs, including CHIP/CCUS, MDS, AML and MDS/MPN. Among those, in 76 (64%) pts the TP53 Y220C mutation was detected at initial diagnosis and in 43 (36%) pts, TP53 Y220C was identified in the relapsed/refractory setting. Therapy-related myeloid neoplasms (MNs) accounted for 51 of 119 pts (41%). Complex karyotype was frequent (n=88/119, 74%) in the setting of TP53 Y220C. Median TP53 Y220C variant allele frequency (VAF) was 32% (range, 1%-96%). Eighty-two patients (69%) had additional co-mutations: 24 (20%) pts had additional (non-Y220C) TP53 mutations only; 34 (29%) pts had only non- TP53 co-mutations (most frequently DNMT3A and TET2) and 24 (20%) pts had additional TP53 mutations in the setting of other co-mutations. With a median follow-up of 9 months, median OS for patients with newly diagnosed TP53 Y220C MDS (n=39) and AML (n=23) was 13.1 months (95% CI, 7.6 to 18.7) and 8 months (95% CI, 5.6 to 13.4), respectively ( p=0.06) (Figure 2). For the TP53 Y220C MDS cohort, AML transformation occurred in 13 (33%) patients, after a median of 14.3 months. Median LFS for these patients was 12.2 months (95% CI, 7.9 to 16.5). Modest and non-statistically significant differences in median LFS for MDS patients who did and did not receive stem cell transplant (SCT) were identified; MDS+SCT (n=12) 14.5 months (95% CI, 4 to 25) vs MDS+no-SCT (n=27) 9.3 months (95% CI, 4.6 to 14), p=0.18. Interestingly, four patients diagnosed with TP53 Y220C mutated CHIP/CCUS with a median VAF of 2% were identified, and with a median follow-up of 34.6 months, none have developed dysplastic changes or progression to MDS or AML at the time of cut off. Additional outcomes data will be forthcoming in the analysis of this cohort of patients with TP53 Y220C mutated myeloid neoplasms. Conclusions: TP53 Y220C mutations are present in malignant blood disorders and are particularly more common in myelodysplastic syndromes and acute myeloid leukemia, with associated poor outcomes. Novel targeted therapies for this TP53 variant (Y220C) would be of interest for this patient population.

Clinico-Genetic and Prognostic Analyses of 635 Patients with Myelodysplastic Neoplasms Based on the 2022 World Health Organization Classification

Myelodysplastic neoplasms (MDS) are a heterogeneous group of clonal myeloid neoplasms characterized by dysregulated hematopoiesis. In the past several years, major advances in molecular technologies and the development of next generation sequencing have deepened our understanding of MDS pathobiology. Revisions of the existing classification were warranted. Under the aegis of the International Agency for Research on Cancer, the 2022 World Health Organization (WHO) classification was released. The 2022 WHO proposed new categories including MDS with biallelic TP53 inactivation (MDS-bi TP53), MDS, hypoplastic (MDS-h) and MDS with fibrosis (MDS-f). In addition, the novel risk scoring system-Molecular International Prognostic Scoring System (IPSS-M) has been established. There are limited data that explore the application of the 2022 WHO classification of MDS in light of the IPSS-M. In this study, a cohort of 635 patients diagnosed as having primary MDS based on the 2022 WHO criteria was retrospectively reviewed. We aimed to elucidate the differences in genetic features and clinical outcomes among patients with different MDS subtypes, based on the 2022 WHO classification. The survival impact of allogeneic hematopoietic stem cell transplantation (allo-HSCT) was also evaluated. TruSight myeloid sequencing panel and the HiSeq platform were used to analyze the alterations of 54 myeloid neoplasm-relevant genes. Comparison of the genetic profiles of patients with different subtypes of MDS showed that patients with MDS-low blasts (LB) and those with MDS with LB and ring sideroblasts (RS) exhibited comparable mutation profiles, while patients with MDS- SF3B1 had different mutation pattern from that of these two subtypes. Among patients with MDS-increased blasts-1 (IB1), MDS-IB2 and MDS-f, patients with MDS-IB2 had higher frequencies of NRAS (9% vs. 2%, P=0.019) and mono-allelic TP53 (7% vs. 1%, P=0.031) mutations, and a trend of more TET2 (19% vs. 10%, P=0.059) mutations than those with MDS-IB1. In addition, patients with MDS-f exhibited lower incidence of TET2 (0% vs. 19%, P=0.020), and STAG2 mutations (8% vs. 27%, P=0.050) as compared to those with MDS-IB. Furthermore, patients with MDS-bi TP53 had specific concurrent genetic alterations with few co-occurring mutations which differed from those found in patients with MDS-IB or MDS-f. We performed pairwise survival comparisons among each subtypes of MDS (Figure 1). In low-risk MDS, patients with MDS-h had significantly longer median leukemia-free survival (LFS) and overall survival (OS) (185.5 months for median LFS and OS) compared with those with MDS-LB and RS [38.3 months for median LFS ( P=0.013) and OS ( P=0.010)], while had a similar outcome compared to those with MDS-LB [170.2 months for median LFS ( P=0.152) and OS ( P=0.146)], and MDS- SF3B1 [114.6 months for median LFS ( P=0.549) and OS ( P=0.528)]. For patients with increased blasts or bi TP53 mutations, those with bi TP53 inactivation had the worst outcomes (median LFS: 3.9 months and OS: 4.5 months, all P<0.001) compared to those with MDS-f (median LFS: 16.6 months and OS: 17.7 months), MDS-IB2 (median LFS: 10.0 months and OS: 17.7 months), and MDS-IB1 (median LFS: 25.6 months and OS: 31.4 months). Patients with MDS-f had similar survival to those with MDS-IB2 and IB-1 in terms of LFS (16.6 vs. 25.6 months, P=0.271) and OS (17.7 vs. 31.4 months, P=0.194) . Multivariable analysis showed that IPSS-M ( P<0.001), old age (HR for LFS: 1.023; for OS: 1.032, P<0.001), and the 2022 WHO categorization ( P<0.001) could predict LFS and OS independently and that HSCT could improve LFS (HR, 0.492, P=0.001) (Table 1). Subgroup analysis of the impact of transplantation using time-dependent Cox regression revealed that allo-HSCT could prolong both LFS and OS in patients with MDS-IB1 (HR for LFS: 0.293, for OS: 0.350, P<0.001), LFS alone (HR: 0.534, P=0.049) in patients with MDS-IB2, and a trend of LFS (HR: 0.305, P=0.078) in patients with MDS-f. However, allo-HSCT failed to remedy the dismal outcomes for patients with MDS-bi TP53. In conclusion, based on the evidence gathered from this cohort analysis, the 2022 WHO classification promote efficient segregation of this heterogeneous disease, with focus on the differences in molecular features and prognoses across different disease subtypes, leading to accurate MDS diagnosis and effective risk-adapted treatment.

Influence of Bone Marrow Blast Enumeration and Co-Occurring Myelodysplasia Related Gene Mutations in NPM1-Mutated Myeloid Malignancies

Introduction Both World Health Organization (WHO 5th) and International Consensus Classification (ICC) guidelines recognize mutations in nucleophosmin 1 ( NPM1mut) as a class defining molecular event in acute myeloid leukemia (AML). WHO 5th omitted the blast percentage requirement and ICC lowered the blast threshold to 10%. NPM1mut AML without FLT3 ITD or adverse risk cytogenetics is considered favorable risk in European LeukemiaNet (ELN) 2022, however co-occurring adverse-risk myelodysplasia related mutations (MR mut) do not influence ELN 2022 risk stratification. This analysis addresses the prognostic impact of blast enumeration in NPM1mut myeloid neoplasms (MN) with <10% blasts and influence of co-occurring mutations in NPM1mut AML. Methods We interrogated publicly available data from adult (≥18 years) patients (pts) with chronic myeloid neoplasms included in the International Working Group for Prognosis in MDS (N= 3,323; Bernard et al. NEJM Evid 2022) and two independent AML cohorts (AMLSG [N=1540] Papaemmanuil et al. NEJM 2016; UKNCRI [N=2,113] Tazi et al. Nat. Commun. 2022). Between group differences were assessed using the Wilcoxon rank-sum test or Fisher's exact test as appropriate. Time to event endpoints were analyzed using the log-rank method. Multivariate analysis (MVA) used cox proportional hazards regression. Results NPM1 mut was identified in 17% (N=1148) of pts (AML: 30% [1109/3653], MN with <20% blasts: 1.2% [39/3,323]). Compared to pts with NPM1mut AML, pts with NPM1mut MN (MDS, CMML, aCML) with blast < 20% were older (median age 65 vs. 55 years, p < 0.001), had a lower median total WBC count (5 vs. 32 x10 9 /L, p < 0.001) and bone marrow (BM) blast percentage (8% vs. 76%, p < 0.001). No significant difference was observed between NPM1mut AML and MN with <20% blasts in median hemoglobin (9.1 vs. 9 x10 9, p: 0.44), platelets (62 vs. 66 x10 9 /L, p: 0.55), or NPM1mut variant allele frequency (VAF; 35% vs. 37%, p: 0.64). After a median follow up of 4.7 years (range: 0-12), no difference in overall survival (OS) was observed between pts with low blast (LB; <10%) NPM1mut MN (N=19) vs. ≥10% blasts (N=18) (median OS: 0.64 years [95% CI: 0.31-3.0] vs. 1.1 years [95% CI: 0.95-NR], p=0.32). Median leukemia free survival (LFS) was 0.81 years (95% CI: 0.67-1.5) and not significantly different between NPM1mut MN pts with <10 vs. ≥10% blasts (median LFS: 0.55 vs. 0.91 years, p=0.27). In pts with NPM1mut AML (N=1109), 52% (N=581) were ELN 2022 favorable-risk; 15% (N=92) had MR mut including SRSF2 (51%, N=47), STAG2 (21%, N=19), ASXL1 (9%, N=8), BCOR (9%, N=8), RUNX1 ( 8%, N=7), EZH2 (5%, N=5), SF3B1 (5%, N=5), U2AF1 (1%, N=1), and ZRSR2 (1%, N=1). Pts with MR mut were older (median age 62 vs. 53 years, p < 0.001), had higher BM blasts (80% vs. 72% p=0.019), and lower platelets (45 vs. 77 x10 9/L p < 0.001) compared to pts with NPM1mut AML without MR mut. No significant difference in NPM1mut VAF was observed (34% in both groups). After a median follow up of 3.5 years (range: 0-15), median OS was 6.2 years in pts with NPM1mut AML (95% CI: 4.2-9.7). Inferior OS was observed in ELN favorable risk NPM1mut pts with vs. without MR mut, respectively (2 vs. 8.4 years, p=0.0001). When stratified by age < 60 vs. ≥ 60 years, younger pts with MR mut had an increased risk of death (HR 1.7 95% CI: 1.1-2.8, p: 0.02). No OS difference was observed in older pts with or without MR mut (HR: 1.2, 95% CI: 0.80-1.68, p=0.44), however OS was significantly shorter in older pts with NPM1mut compared to younger pts (median 1.7 years vs. NR, p < 0.001). Patients with NPM1mut /MR mut AML had survival comparable to patients with ELN 2022 intermediate risk AML (2.0 vs. 2.1 years, p=0.35). In MVA of NPM1mutAML adjusted for MR mut, BM blast percentage, age, performance status, baseline WBC, hemoglobin, platelet count, NPM1mut VAF, and treatment setting (AMLSG or UKNCRI), the presence of an MR mut (HR 1.39 [95% CI: 1.0-1.9], p=0.04), age < 60 (HR 0.43 [95% CI: 0.32-0.56], p < 0.001), and performance status (HR 1.35 [95% CI: 1.14-1.60], p=0.0004) retained statistical significance. Conclusion Pts with low blast NPM1mut MN have outcomes similar to pts with NPM1mut AML, supporting NPM1mut as an AML defining event irrespective of BM blast enumeration. In patients with ELN favorable risk NPM1mut AML, co-occurrence of MR mut is independently associated with inferior survival, comparable to ELN intermediate risk AML. These results may inform future refinements of current consensus guidelines.

Predictors of survival outcomes in patients with MECOM EVI1 rearrangement aberrations in AML or MDS.

e19078 Background: MECOM (EVI1) rearrangements in MDS/AML are rare and carry an unfavorable prognosis. Although allogeneic stem cell transplantation (allo-HSCT) may prolong survival, factors impacting outcomes are not known. We conducted a retrospective analysis of patients with MECOM (EVI1) to associate clinicopathologic variables with prognosis. Methods: This study was approved by the Mayo Clinic IRB. Patients >18 years of age with MDS or AML and MECOM EVI1 at Mayo Clinic between 01/2012 and 12/2022 were included. Response was defined by ELN criteria. Intensive chemotherapy was defined as 7+3 or high dose cytarabine. Non-intensive chemotherapy included hypomethylating agents with or without venetoclax. Median overall survival (OS) and median leukemia free survival (LFS) were estimated using the Kaplan-Meier method. Outcome differences between sub-groups and univariate analyses were assessed with Cox regression. Results: Sixty patients met criteria for inclusion. Sixty-three percent (n = 38) were male and the median age at diagnosis was 67.8 yrs (range, 56 – 75). Eighty percent had AML (n = 48) and 18% had MDS (n = 11). Sixty-seven percent of patients had secondary AML/MDS (n = 40). Inv(3)/t(3;3) was present in 65% (n = 39) and t(3;21) was present in 12% (n = 7). Thirty-eight percent (n = 23) of patients had cooccurring monosomy 7 or 7q deletion and 5% had complex karyotype (n = 3). SF3B1 was the most common cooccurring mutation in 31% (n = 10), followed by KRAS in 19% (n = 6). Thirty-eight percent of patients (n = 23) received intensive chemotherapy. Complete response (CR) rates were 36% with intensive treatment (n = 8) and 4% with non-intensive treatment (n = 1; p = 0.007). Thirty percent (n = 18) underwent SCT (78% in CR1 and 22% in CR2) and of those, myeloablative conditioning (MAC) was used in 38% while 61% received reduced intensity conditioning (RIC). The mOS in the entire cohort was 11 months (95% CI 6.2, 17). Patients who received a SCT had longer mOS compared to patients who did not (19 vs 6.2 months, HR = 0.31, 95% CI 0.16,0.64; p = 0.001). AML-MRC was a poor prognostic factor in the HCST group for OS (HR = 4.23, 95% CI 1.02, 17.5, p = 0.047). Intensive vs. non-intensive chemotherapy, response prior to transplant (CR vs. no CR), or having 2 or more mutations on NGS did not significantly impact OS or LFS. Conclusions: In line with previous reports, allo-HSCT was associated with improved survival outcomes. Our results showed a high frequency of secondary AML/MDS, but only AML-MRC was associated with decreased survival outcomes. Regardless of therapy type, outcomes were poor. Novel therapies are urgently needed for these patients.

Assessment and validation of the molecular international prognostic scoring system for myelodysplastic syndromes.

The Molecular International Prognostic Scoring System (IPSS-M) is a novel risk stratification model for myelodysplastic syndromes (MDS) that builds on the IPSS and IPSS-R by incorporating mutational data. The model showed improved prognostic accuracy over the IPSS-R across three endpoints: overall survival (OS), leukemia-free survival (LFS) and leukemic transformation. This study aimed to validate the findings of the original in a large cohort of MDS patients, as well as assess its validity in therapy-related and hypoplastic MDS. We retrospectively reviewed clinical, cytogenetic and molecular data for 2355 MDS patients treated at the Moffitt Cancer Center. Correlative analysis between IPSS-R and mean IPSS-M scores and outcome predictions was performed on LFS, OS and leukemic transformation. Using the IPSS-M, patients were classified as Very Low (4%), Low (24%), Moderate-Low (14%), Moderate-High (11%), High (19%) and Very-High risk (28%). Median OS was 11.7, 7.1, 4.4, 3.1, 2.3, and 1.3 years from VL to VH risk subgroups. Median LFS was 12.3, 6.9, 3.6, 2.2, 1.4, and 0.5 years respectively. For patients with t-MDS and h-MDS the model retained its prognostic accuracy. Generalized use of this tool will likely result in more accurate prognostic assessment and optimize therapeutic decision-making in MDS.

An Assessment of the Three Popular Prognostic Scoring Systems for Chronic Myelomonocytic Leukemia (CMML) in an Indian Context

Abstract Introduction: Chronic myelomonocytic leukemia (CMML) is a rare clonal hematopoietic neoplasm with a prevalence of 1.05 to 1.94 cases per 1,00,000 population. There are multiple prognostic scoring system used in practice for CMML, which include both cytogenetic and next-generation sequencing based. Objective This study assesses the clinicohematological profile of CMML patients, along with comparison of three widely used prognostic scoring systems for CMML (CMML-specific prognostic scoring system, MD Anderson prognostic score, Mayo prognostic model). Materials and Methods: This study is an 8-year retrospective study. All relevant data had been retrieved and reviewed by the authors. Inclusion and exclusion criteria: All the cases that were diagnosed before 2016 as per 2008 criteria were reclassified, (2) all the cases that were positive for the mutations associated with myeloproliferative neoplasms were excluded, and (3) cases with more than or equal to 20% blast/blast equivalents were excluded. A univariate analysis was done followed by a multivariate analysis for all the parameters constituting each scoring system. Lastly, a receiver operating characteristic curve was plotted for all the three scoring systems. Result: There were total 23 patients, with a median age of 63 years and a male to female ratio of 2.3:1. Cytogenetic aberration and genetic mutation were observed in 6 and 3 cases, respectively. The median overall survival (OS) was 48 months and the median leukemia-free survival was 12 months. Post-multivariate analysis, the parameters with significant impact on OS were absolute monocyte count more than 10 × 10^9/L, myeloid precursors in peripheral blood, hemoglobin less than 10g/dL, platelet less than 100 × 10^9/L, hemoglobin less than 12g/dL, and absolute lymphocyte count more than 2.5 × 10^9/L. Conclusion: To summarize, we discovered CPSS to be a better prognostic tool for a setup like ours, since molecular investigations are not always readily available for each case. More such researches are needed in the near future so that we can design better prognostic tools and see for their usefulness in real life.

A retrospective study of cladribine and low-dose cytarabine-based regimens for the treatment of chronic myelomonocytic leukemia and secondary acute myeloid leukemia.

Patients with higher risk chronic myelomonocytic leukemia (CMML) have limited therapeutic options beyond hydroxyurea and hypomethylating agents (HMAs). Regimens based on a backbone of cladribine (CLAD), low-dose cytarabine (LDAC), and an HMA are effective low-intensity therapies for acute myeloid leukemia (AML). The authors conducted a retrospective chart review to evaluate the efficacy of CLAD/LDAC/HMA in CMML and secondary acute myeloid leukemia (sAML) arising from CMML. Responses were evaluated according to the 2006 International Working Group criteria for CMML and the 2017 European LeukemiaNet criteria for AML. The overall survival (OS), leukemia-free survival (LFS), and duration of response were evaluated with the Kaplan-Meier method. Patients were stratified on the basis of prior HMA exposure. The authors identified 21 patients with CMML (eight with HMA-naive CMML and 13 with HMA-failure CMML) and 33 patients with sAML (11 with HMA-naive sAML and 22 with HMA-failure sAML) treated with CLAD/LDAC/HMA-based regimens. The CMML cohort was enriched for high-risk features (proliferative type, elevated blasts, and RAS/MAPK mutations). The overall response rate was 33% in CMML (50% in HMA-naive CMML and 23% in HMA-failure CMML) and 48% in sAML (82% in HMA-naive sAML and 32% in HMA-failure sAML). The median OS was 14.4, 8.8, 42.9, and 2.9months for HMA-naive CMML, HMA-failure CMML, HMA-naive sAML, and HMA-failure sAML, respectively. The median LFS was 14.4 and 3.9months for HMA-naive CMML and HMA-failure CMML, respectively. CLAD/LDAC/HMA-based regimens are effective in a subset of patients with higher risk CMML and sAML arising from CMML who have not previously experienced HMA failure. These findings must be confirmed in prospective studies.

Validation of the Molecular International Prognostic Scoring System (IPSS-M) Risk Stratification Model for Myelodysplastic Syndromes

Background The Molecular International Prognostic Scoring System (IPSS-M) is a newly developed risk stratification model for myelodysplastic syndromes (MDS) that expands on the original IPSS-R by including data on somatic oncogenic mutations across 31 gene families and weighing their impact on prognosis and outcomes. The discovery model demonstrated improved prognostic discrimination relative to the IPSS-R in regard to overall survival (OS), leukemia-free survival (LFS) and leukemic transformation, by substratifying pts into six risk categories, and led to restratification of 46% of cases. Adequate risk stratification in MDS is critical for therapeutic decision-making. Here we aimed to externally validate the findings of the original study using a large cohort of pts treated at a tertiary referral center. Methods A total of 2355 MDS pts treated at Moffitt Cancer Center with available clinical and molecular data were analyzed. For estimation of the IPSS-M score, R version 4.2.1 was used to run batch-calculation using syntax code provided by the Papaemmanuil lab at MSKCC. The mean IPSS-M score was used as reference. Correlative analysis between IPSS-R and mean IPSS-M scores and outcome predictions was performed on LFS, OS and leukemic transformation. Time-to-event analyses were estimated using the Kaplan-Meier method and groups were compared by the log-rank test. We used Cox proportional hazards models for survival endpoints. For model discrimination we used Harrell's C concordance index. Results We identified at least 4,327 driver point mutations involving up to 170 genes across 2355 pts. We identified at least one gene mutation in 83% of pts (1948). Median follow-up was 4.6 yrs (4.4-4.9). 2333 pts (99%) were classified. Table 1 shows baseline clinical and molecular characteristics between validation and discovery cohorts. Using the IPSS-M risk stratification schema, pts in the validation cohort were classified as Very Low (96, 4% vs 14% in the discovery cohort), Low (560, 24% vs 32%), Moderate Low (327, 14% vs 11%), Moderate High (258, 11% vs 11%), High (454, 19% vs 14%) and Very High (660, 28% vs 18%) (Fig. 1A). The validation cohort was comprised of sicker pts with higher risk disease per IPSS-M relative to the discovery cohort (47% vs 31%). The IPSS-M score resulted in improved discrimination relative to the IPSS-R regarding LFS, OS and leukemic transformation as evidenced by a 2.3-, 2.0- and 1.5-point increase in C-index. The IPSS-M categories showed significant separation across all examined endpoints. Median LFS and OS estimates were equivalent between validation and discovery cohorts. Median LFS was 12.3 (vs 9.7), 6.9 (6.0), 3.6 (4.1), 2.2 (2.3), 1.4 (1.7) and 0.5 (0.7) yrs from Very Low to Very High-risk categories (Fig. 1B-1C). Conversely, median OS was 11.7 (vs. 10.6), 7.1 (6.0), 4.4 (4.6), 3.1 (2.8), 2.3 (1.7) and 1.3 (1.0) yrs from VL to VH subgroups (Fig.1). A five-to-five mapping between the IPSS-R and IPSS-M risk subgroups (from combining moderate-low (ML) and moderate-high (MH) into moderate), resulted in the restratification of 45% of pts (1056), equivalent to the discovery cohort (46%). Almost 3/4 of pts classified as IPSS-R very-low (VL) were upstaged (majority to IPSS-M low and ML/MH). Almost half of pts classified as IPSS-R intermediate shifted: 39% (174) were reclassified as IPSS-M high/very high (H/VH). Similarly, about 42% of pts classified as IPSS-R high were upstaged to IPSS-M VH. Almost 20% of VH risk pts were downstaged (majority to high risk). Most significant was the reclassification of 10.5% (244) of the validation cohort from IPSS-R lower and intermediate risk categories into IPSS-M higher risk strata. Contextually, the restratification of pts from IPSS-R intermediate to higher risk strata in IPSS-M was associated with notable differences in survival outcomes which were as poor as 0.5 yrs and as high as 6.9 yrs for those reclassified as LR (relative to 1.9 yrs). Conclusion To our knowledge this is the first external validation of IPSS-M in a large cohort. Use of the IPSS-M model for the risk stratification of pts with MDS resulted in improved discrimination of LFS, OS and risk of leukemic transformation over the IPSS-R. Furthermore, it led to restratification of almost half of MDS pts and exposed important differences in survival outcomes. Generalized use of this tool will likely result in more accurate prognostic assessment and optimize therapeutic decision-making among MDS pts. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Outcomes of Patients Treated with Low-Intensity Re-Induction Therapy for Persistent Disease after a Single Intensive Induction Cycle for Newly Diagnosed Acute Myeloid Leukemia (AML)

Introduction: Intensive chemotherapy with 7+3 or CPX-351 remains standard of care for fit adults with newly diagnosed AML. Nearly 50% achieve a remission after one induction cycle, and up to an extra 20% can achieve remission after a second intensive cycle. However, intensive re-induction increases morbidity through significant prolongation of cytopenias. Furthermore, certain patients (pts) may be less likely to respond to intensive re-induction, namely those with adverse risk disease. Recently, with effective non-intensive options, such as venetoclax (Ven) combinations, or IDH inhibitors, we offered low intensity re-induction to select pts with persistent disease after initial intensive therapy as a potential means of reducing morbidity, and potentially improving chance for response. This study describes the characteristics and clinical outcomes of pts with residual disease after intensive induction, treated with either Ven or IDH inhibitor re-induction. Methods: A chart review of ND-AML pts treated between 1/2017 and 2/2022 was performed. We identified pts who either received 7+3 or CPX-351 for initial induction. We then selected pts who had a nadir BM biopsy demonstrating persistent AML (>5% blasts), who then received either a Ven combination or an IDH inhibitor as next treatment. To characterize pt burden, we collected hospitalization duration, PRBC and platelet transfusion burden over 30 days after re-induction, neutropenic fever rates, ICU admission rates, and death within 30 days. We also collected clinical outcomes including CRc after 1 cycle of therapy, best response, proportion of pts proceeding to allogeneic HCT (alloHCT), and leukemia free survival (LFS). Results: A total of 15 pts were identified. Median age of pts was 61 years (22-67), 5 (33%) pts had ELN intermediate risk disease, 10 (67%) pts had ELN adverse risk disease; 5 (33%) pts had mutations in IDH1/2, and 4 (27%) pts had mutations in TP53. Most pts, 11 (73%), received initial induction with 7+3 chemotherapy; on post induction nadir marrow, a median 34% (10-90%) blasts were observed. For re-induction, 11 (73%) pts received a Ven combination (either with decitabine or azacitidine), and 4 (27%) received an IDH1 inhibitor (with azacitidine in 2 pts). Most common reason documented for re-induction choice was adverse risk disease, followed by presence of IDH mutation, followed by loss of fitness for additional intensive therapy. Median hospitalization duration from induction day 1 was 27 days (20-41); median time in hospital after re-induction was initiated was 6 days (0-27). After initiation of re-induction therapy, over the next 30 days, median number of PRBC transfusions administered to these pts was 1 (0-8), median number of platelet transfusions was 2 (0-17). Overall, 2 (13%) pts were re-hospitalized for neutropenic fever, including 1 (8%) pt who was admitted to the ICU and subsequently died (Table 1). In terms of response, 9 (60%) pts achieved a CRc after one cycle of low-intensity therapy. This includes 6 pts who received a Ven combination, and 3 patients who received ivosidenib (with or without azacitidine). Subsequently, 8 (73%) pts on a Ven combination achieved a CRc as best response, and 4 (100%) pts achieved CRc utilizing ivosidenib (Table 1). Ten (67%) pts proceeded to alloHCT. Overall, median leukemia free survival was 377 days (95% CI 235-518), and 7 (47%) pts remain alive at last follow-up (Figure 1). Conclusion: Among pts with residual disease after initial intensive induction, switching to a Ven combination or IDH inhibitor potentially reduces pt burden through shorter hospital stays, and lower burden of neutropenic fevers and transfusions. Furthermore, this strategy has promising efficacy, and serves as a successful bridge to alloHCT. A control cohort of pts receiving intensive re-induction is being composed from pts treated at our institution and will add further context. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Persistence of Mutations in Complete Remission Including DNMT3A, TET2 and ASXL1 Mutations Is Associated with Worse Prognosis in Patients with Acute Myeloid Leukemia Treated in ALFA 0702 Study

Background: Only few studies have validated the use of molecular minimal measurable residual disease evaluation using error-corrected NGS (NGS-MRD). The prognostic relevance of detection of isolated DNMT3A, TET2 or ASXL1 (DTA) mutations post-induction remains controversial. Benchmarking of NGS-MRD with respect to other molecular MRD tools (such as WT1 expression and NPM1 mutation) has yet to be conducted. Material and methods: All patients included in the ALFA-0702 study who reached cytological complete remission (CR) or CR with incomplete platelets recovery after one induction course and with available material were included (n=189). Standard NGS sequencing of 67 genes was performed at diagnosis. Error-corrected NGS was performed on post-induction bone marrow samples using a custom panel including all mutations identified at diagnosis (n=735 mutations in 51 genes). Median sequencing depth in CR was 24695x after UMI deduplication. A threshold of 0.1% VAF was set as cut-off value for NGS-MRD detection for all targets. WT1 expression data in CR were available in 100 patients with initial WT1 over-expression. NPM1-MRD was evaluated in 67 patients by error-corrected NGS. For this evaluation, one alternative read was considered sufficient to define positivity. Leukemia free survival (LFS) and overall survival (OS) probabilities were evaluated since CR. Results: Median age at diagnosis was 46 years. ELN2017 risk was favorable in 52 (27%) patients, intermediate in 75 (40%) and unfavorable in 60 (32%). With a median follow-up from CR of 47 months, median LFS and OS was 35 and 41 months respectively. At diagnosis, gene mutations were detected in 181 (95%) patients. The median number of mutations per patient was 4 (range 1-10). Ninety-one patients had no target detected (NGS-MRD neg) and ninety had at least one target detected (NGS-MRD pos) including 42 patients with detection of DTA mutations only (DTA-MRD). NGS-MRD pos patients were significantly older (p=0.0018) than NGS-MRD neg patients and harbored a higher median number of mutations at diagnosis (4 vs 3, p=0.0021). There were no significant differences in terms of demographics and clinical presentation (age, WBC, number of mutation) between patients with DTA-MRD and non-DTA-MRD patients. In univariable analyses, NGS-MRD pos was associated with a lower probability of LFS (4-years LFS: 44% vs 68%, p= 6e-04) and OS (4-years OS: 57% vs 81%, p= 9e-04). There was no impact of the initial number of mutations on LFS nor OS. There were no significant differences in LFS and OS between DTA-MRD and non-DTA-MRD patients (figure 1). When adjusting analysis on ELN2017 status, MRD-NGS pos remained associated with shorter LFS (HR 2.15[1.34-3.44] , p=0.001) and OS (HR 2.41[1.38-4.20] p=0.002). As a continuous variable, the number of mutations detected in CR was associated with shorter LFS and OS. Specifically, detection of ≥2 mutations predicted poorer LFS (HR, p=3e-05) and OS (HR, p=4 e-05), compared with detection of only 1 mutation (figure 2). Sixteen patients were positive for WT1 MRD evaluation, and 84 were negative (WT1 neg). Among the WT1 neg patients 37 were NGS-MRD pos and 47 were NGS-MRD neg. When adjusting for both ELN17 and WT1 expression in CR, there was no significant impact of MRD-NGS positivity on LFS (HR=1.62 [0.85 - 3.09]) nor OS (HR=1.28 [0.59 - 2.74]) In the 67 patients with NPM1 mutation, 41 patients had NPM1 undetectable MRD (including 21 NGS-MRD pos and 20 NGS-MRD neg) and 26 had detectable NPM1-MRD (including 16 NGS-MRD pos and 10 NGS-MRD neg). When adjusting for both ELN status and NPM1-MRD, NGS-MRD pos was associated with a non-significant trend towards lower LFS (HR=2.34[0.96-5.71] p=0.063). Discussion and conclusions: In the homogeneously treated ALFA-0702 population, MRD-NGS positivity after the first induction course predicts shorter LFS and OS independently of ELN17 risk stratification. Detection of a higher number of mutations in CR is associated with a worse prognosis. Contrary to previous studies accruing older patients treated less intensively persistence of DTA mutations has similar prognostic relevance than non-DTA mutations. Future studies will be necessary to determine the superiority or addivitity of NGS-MRD with respect to available molecular MRD tools. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal