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Classical hematological disorders encompass a broad array of congenital and acquired blood conditions, ranging from thrombotic and hemorrhagic disorders, hemoglobinopathies such as sickle cell disease/thalassemia, abnormalities in blood counts, disorders of iron metabolism, obstetric hematologic conditions, and rare genetic hematologic diseases. The past decade has seen a revolution in research and therapeutic development for these disorders. It has led to FDA approval of novel therapies such as gene therapies for hemophilia and hemoglobinopathies, targeted therapies for coagulation and complement disorders, factor VIII mimetics, new immunotherapeutic targets for cytopenia and genomic-directed diagnosis and therapy for a wide range of blood disorders. Between January 2018 and July 2023, 34 new drugs have been approved for different classical hematological disorders, and several more have received approval for new or expanded indications. This is changing how we treat patients with classical hematological conditions. Most classical hematological disorders have an impact on patients' quality of life as well as life span, and for decades, many of these disorders were managed with limited therapy options with variable efficacy. Rare hemolytic disorders such as cold agglutinin disease, paroxysmal nocturnal hemoglobinuria, thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome, sickle cell disease, thalassemia, porphyria all have expanded options. Newer agents for the management of anemia, thrombocytopenia and leukopenia in different clinical settings are available. Lastly, management of hemophilia is being revolutionized by extended half-life products, non-factor options and gene therapy. Hemophilia care has always been deemed to be costly, but gene therapy is getting additional attention due to the high price tag. We have compiled the list of all new drugs that got FDA approval for classical hematological disorders over past 5 years and plan to present this in the form of an infographic providing details on the drug along with its indication, trial leading to approval and cost implications of each therapy. Our intention is to summarize the drug development for classical hematology and highlight “not so benign” nature of these disorders and related therapy particularly in terms of financial toxicity for the patients.

Background: For patients with chronic lymphocytic leukemia (CLL)-the most common form of leukemia in older adults-equitable access to care is particularly challenging, as the disease is often diagnosed in community cancer centers encumbered by regional disparities. Therefore, identifying and understanding regional barriers to care is essential. In 2020, the Association of Community Cancer Centers (ACCC) developed a heat map detailing the incidence rate of CLL diagnoses across the country (Fig.1), overlayed with the locations of CLL “expert” providers, revealing the areas in the US most in need of additional CLL clinical expertise (Fig. 2). In 2022, these incidence rates were stratified by race, ethnicity, and metropolitan statistical area to identify disparities Building on these maps, ACCC set out to identify specific regional challenges to appropriate, equitable care for patients with CLL. Methods: As part of an independent education program, ACCC initiated conversations with providers about the regional barriers that patients with CLL face. Through 4 webinars in February 2023, participants from 4 regions-Northeast (New York and Maine), Northwest (Montana and Idaho), Midwest (Wisconsin, Illinois, and Iowa), and Southwest (Texas)-shared insights on challenges and exchanged ideas on strategies to improve care for patients with CLL. In addition, ACCC interviewed 3 regionally diverse cancer programs (from the US Northwest, South, and Southwest regions) that are effectively overcoming regional challenges to reach their patient populations and provide equitable care. These interviews highlighted barriers and challenges, showcased effective outreach campaigns, and explored how the outreach improved the patient journey. Findings: The following themes emerged as key challenges and potential solutions throughout all regions studied: (1) Comprehensive Diagnostic Work-up Before Treatment Initiation: A key component in caring for patients with CLL is identifying certain disease related criteria prior to formulating a treatment plan. This includes determining the disease burden, disease-related symptoms, and if the patient meets certain active disease criteria (eg, Binet Stage C or Rai Stage III or IV). Further, by utilizing genetic testing, such as the TP53 gene mutation and IGHV mutation tests, physicians can estimate time to treatment and choice of specific novel targeted therapies. (2) Understanding Patient Population Needs: Cancer programs must understand the needs of their unique patient populations to effectively address them. For example, in the Northwest, as mountainous passes can make travel dangerous at times, one local program utilizes near-campus housing/hotel space for patients for the duration of their intensive treatment. In the Southwest, addressing health insurance coverage, low health literacy, language barriers, patient-provider mistrust, and culturally competent care for undocumented individuals presents challenges to equitable care delivery. Therefore, cancer programs in this region have implemented protocols to utilize community and social services to help support these patients. (3) Developing Community Partnerships: As the median age of diagnosis with CLL is approximately 70 years old, barriers such as transportation availability, caregiver support and financial constraints could be magnified. Building trust, particularly among vulnerable communities, also presents a significant challenge. By partnering with community outreach organizations, programs can help address these issues through community resources such as ride share programs, transportation vouchers, and financial assistance programs. (4) Provider Education and Learning: Because many patients are diagnosed in community cancer programs and smaller practices where physicians do not often have experience with CLL, nationally available provider education on new developments in testing and treatments is key. Conclusions: ACCC identified regional challenges and solutions to appropriate and equitable care for patients with CLL, including the importance of comprehensive diagnostic work-up before treating, understanding the regional needs of patient populations (particularly underserved populations), building community partnerships, and engaging in targeted provider education.

Background: Myelodysplastic/Myeloproliferative neoplasms (MDS/MPN) represent a group of rare hematologic malignancies, distinguished by their concurrent dysplastic and proliferative features. Patients with these neoplasms have an increased risk of acute leukemia transformation and often present with extramedullary and constitutional symptoms. The only approved therapies for MDS/MPNs are hydroxyurea, decitabine (oral decitabine/cedazuridine and parenteral decitabine) or azacitidine (parenteral) for pts with CMML. Given the rarity and the heterogeneity of MDS/MPNs, prospective studies focusing specifically on MDS/MPN have been uncommon, and refining treatment strategies has been difficult. ABNL-MARRO ( A Basket study of Nove l therapy for untreated MDS/MPN and Relapsed/ Refractory Overlap Syndromes) is an international cooperative effort that leverages the expertise of the MDS/MPN International Working Group (IWG) and provides a framework for collaborative studies around the world to advance treatment of MDS/MPN and to explore clinical and pathologic markers of disease severity, prognosis, and treatment response (Moyo TK et.al BMC Cancer. 2022). Methods: ABNL-MARRO 001 (AM-001) is an open-label, phase 1b/2 study testing the treatment combination of ASTX727 (days 1-5), a fixed dose oral combination pill containing 35 mg of the DNMTi decitabine (DEC) and 100 mg of the cytidine deaminase inhibitor cedazuridine (CED), together with a series of active agents in myeloid disease (see Figure 1a) for MDS/MPN. In arm A, ASTX727 is combined with itacitinib 300 mg (days 1-28), a selective JAK1 inhibitor in newly diagnosed and relapsed/refractory (R/R) pts. Here we report results from the 3+3 dose de-escalation phase 1b portion used to determine the recommended Phase 2 dose (RP2D) in arm A. Dose-limiting toxicities (DLTs) were assessed in cycle 1. Disease response was assessed by the MDS/MPN IWG response criteria (Savona et.al., Blood. 2015). Results: Seven patients were enrolled with a median age 75 (range 32-82) years with newly diagnosed (4 pts) or R/R (3 pts) MDS/MPN. Three patients had CMML, 2 had MDS/MPN-U, and 2 had refractory MDS/MPN RST. One patient was not DLT evaluable given severe disease-induced cytopenia, and was not included in the assessment (patient 4 in Figure 1b). The majority of pts experienced a treatment-emergent adverse event (TEAE) of any grade; the most common (≥30% of pts) were thrombocytopenia (50%), neutropenia (30%), and constipation (30%); 50% of pts experienced a Grade ≥3 TEAE; the most common was neutropenia (30%). No DLTs were reported, and these AEs were consistent with what has been reported in the use of ASTX727 (Savona et al. Blood. 2022). One patient achieved a CR, and two additional patients had the best overall response of optimal marrow response after receiving 6 cycles of treatment. All patients are alive with a median follow-up of 12 months (range 6-17 months). The clinical responses and time-on-treatment of all pts in phase 1b are summarized in Figure 1b. Summary/Conclusion: Based on the preliminary results of the phase 1b study, the dosing schedule of 35 mg DEC / 100 mg CED daily for 5 days in combination with itacitinib 300 mg daily for 28 days was selected as the RP2D as it balanced clinical efficacy with an acceptable and manageable safety profile. This regimen and dose are being utilized in a 28-day cycle in the ongoing global, multi-center phase 2 study (NCT04061421).

Multiple myeloma is the second-most common hematological malignancy in the US that remains a challenging disease to cure despite recent advancements in treatment strategies. Drug resistance is a major cause of concern in myeloma chemotherapy. We have created an optimization-regularization-based computational prediction method called secDrug that identified several novel secondary drug (‘secDrug‘) combinations against drug-resistant myeloma (relapsed/refractory multiple myeloma or RRMM). Top among our predicted secDrugs includes the survivin inhibitor, YM155. Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has dual roles in mitosis and apoptosis. YM155 inhibits survivin at the transcriptional level by inhibiting the survivin gene promoter. Several studies have demonstrated the efficacy of YM155 in solid tumors and heme malignancies, including myeloma. However, the precise mechanism of action is not yet known. MM cell lines express high levels of IAPs. We observed high in vitro cytotoxicity of YM155 as a single agent (IC 50 range 0.41 to 12.85nM) as well as in combination with the primary drugs like proteasome inhibitors and Immunomodulatory drugs (IMiDs) against >15 human myeloma cell lines representing innate/refractory and acquired/emerging (relapse) resistance. Next, we explored the molecular mechanisms underlying the efficacy of YM155 using pre-vs-post-treatment tumor whole-transcriptome analysis (RNAseq). The top differentially regulated genes include DDIT3 (CHOP), ATF3, TXNDC5 SEC24D, and DHX15 ( Figure 1A). Ingenuity Pathway Analysis (IPA) predicted that, in addition to regulating apoptosis, survivin inhibition in myeloma significantly upregulated unfolded protein response and downregulated vehicle trafficking and genes associated with immune cell function. Further, we performed single-cell transcriptomics (scRNAseq; 10X Genomics) analysis to explore treatment-induced changes to the subclonal architecture. Our scRNAseq results revealed a distinct shift in clusters representing myeloma single-cell subpopulations following YM155 treatment ( Figure 1B). For example, Cluster 1 (53.11%), characterized by high expression of cell survival markers Ki67 and MYC, was pre-dominant in untreated myeloma cells, while Cluster 4 (52.19%) was the primary subclone in post-treatment tumors. Cluster 3 was shared between the untreated and treated groups. Detailed distinctions between each single-cell cluster will be presented. Furthermore, our scRNAseq data alluded to the benefits of combining survivin-inhibitors and Hsp90-inhibitors based on the expression of drug target genes. Hsp90 inhibitors indirectly target survivin by disrupting the interaction between survivin and Hsp90, resulting in a destabilized survivin protein that ultimately results in survivin degradation. In fact, we have earlier shown the effectiveness of Hsp90 inhibitors (17-AAG, AICAR, and CCT018159) as potent secDrugs against RRMM. Finally, high-dimensional mass cytometry or CyTOF analysis using heavy metal-conjugated proteins in patient bone marrow-derived primary myeloma cells ( ex vivo model system) showed that YM155 induced dose-dependent reduction of several protein markers implicated in cell survival and chemotherapeutic resistance in multiple myeloma, including myc, Ki-67, CD28, CD81, and CD274 (PD-L1). Previous studies have shown that CD28 and CD81 are high-risk immunophenotypes associated with significantly worse prognosis in patients with myeloma. PD-L1 (Programmed death-ligand 1) is a cell-surface glycoprotein expressed in a large number of malignancies that is involved in the termination of immune response and immune evasion. An earlier study has shown that YM155 enhances daratumumab-mediated cellular lysis of multiple myeloma cells. Our RNAseq and CyTOF results thus suggest a potential basis of synergy between YM155 with immunotherapies approved for myeloma, which we will test further. Our approach thus integrates in silico prediction with single-cell multi-ome analysis to identify molecular mechanisms potentially underlying subclonal response to novel combination therapy candidates (secDrugs) for the treatment of RRMM.

Introduction: Patients with TCE RRMM have a high disease burden and often report worsening HRQoL with additional lines of therapy. The single-arm, phase 2 KarMMa study demonstrated that ide-cel, a B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T cell therapy, improved HRQoL from baseline in patients with TCE RRMM who had received ≥ 3 prior regimens (Delforge M, et al. Blood Adv 2022;6:1309-1318). Furthermore, in the phase 3 KarMMa-3 clinical trial (NCT03651128), ide-cel significantly improved progression-free survival and response compared with standard regimens in patients with TCE RRMM who had received 2-4 prior regimens (Rodriguez-Otero P, et al. N Engl J Med 2023;388:1002-1014). Here we assessed the comparative effects of ide-cel versus standard regimens on HRQoL in patients with TCE RRMM who had received 3-4 prior regimens including an immunomodulatory agent, a proteasome inhibitor, and daratumumab (an anti-CD38 monoclonal antibody) using data from the KarMMa-3 study. Methods: Patient-reported outcomes (PROs) were assessed by the European Organization for Research and Treatment of Cancer (EORTC) Quality-of-Life Questionnaire-Core 30 (QLQ-C30), EORTC Quality of Life Questionnaire Multiple Myeloma Module (QLQ-MY20), and EQ-5D-5L. The pre-specified primary domains of interest included EORTC QLQ-C30 global health status/QoL, physical functioning, cognitive functioning, fatigue, and pain; EORTC QLQ-MY20 disease symptoms and side effects of treatment; and the EQ-5D-5L visual analog scale (EQ-5D VAS). PROs were collected at screening (baseline), the day of ide-cel infusion (ide-cel) or first treatment dose (standard regimens), monthly from 2 to 28 months, and thereafter every 3 months. Comparisons were performed on least squares (LS) mean changes from baseline through 28 months between arms using constrained longitudinal data analysis (cLDA). Effect size was estimated by Hedges' g. The comparative effects of ide-cel versus standard regimens on time to confirmed improvement and time to confirmed deterioration (defined by prespecified change thresholds) were assessed via stratified Cox proportional hazards regression analyses. All P values are nominal and not adjusted for multiple testing. Statistical significance was set at P < 0.05. Results: Baseline characteristics were well balanced among the patients in the ide-cel arm (n = 167) and the standard regimen arm (n = 93), with a median age of 63 years and a median time of 4.7 years from RRMM diagnosis to study screening. Completion rates of HRQoL assessments were high over time for most visits (> 75%). At baseline, mean HRQoL domain scores were similar between arms. Overall LS mean changes from baseline to 28 months showed significant differences in favor of ide-cel versus standard regimens (nominal P < 0.05) for 11 domains (effect sizes of 0.26-0.82), and 7 (4 primary: global health status/QoL, cognitive functioning, pain, EQ-5D VAS; 3 secondary: dyspnea, insomnia, constipation) of them exceeded the prespecified MID thresholds (Table). Time to confirmed improvement was significantly shorter (nominal P < 0.05) in the ide-cel arm than in the standard regimen arm for 10 domains, including all primary domains except pain. Time to confirmed deterioration was longer in the ide-cel arm than the standard regimen arm for most domains, with significant differences in emotional functioning, cognitive functioning, and dyspnea (EORTC QLQ-C30). Finally, side effects of treatment favored the ide-cel versus standard regimen arm (EORTC QLQ-MY20) (Table). Conclusions: These patient-reported findings demonstrate that compared with standard regimens, treatment with ide-cel improved MM-relevant disease symptoms, functioning, and overall health status/HRQoL of patients with TCE RRMM in the KarMMa-3 trial. These data further substantiate the superior treatment outcomes of ide-cel over standard regimens in this patient population. Overall, treatment with ide-cel may help alleviate detriments to HRQoL in these patients with complex disease.

Background Venetoclax (Ven) in combination with hypomethylating agent (HMA) is the standard treatment for newly diagnosed elderly/unfit patients with acute myeloid leukemia (AML). Treatment options for patients with relapsed/refractory (RR) disease following Ven-HMA are limited in the absence of targetable mutations. In a recent phase 2 study, the addition of Ven to cladribine (CDA) plus low-dose cytarabine (LDAC), in newly-diagnosed elderly/unfit AML, resulted in complete remission with (CR) or without (CRi) count recovery rate of 93% ( J Clin Oncol 20;40(33)). In the current study, we share our experience with this regimen in patients relapsed or refractory to Ven-HMA, treated outside of clinical trials. Methods Under an institutional review board approved minimum risk protocol, the Mayo Clinic (MN, AZ, FL) database was searched to identify patients with AML who failed treatment with Ven-HMA and subsequently received at least one cycle of salvage therapy with Ven-CDA-LDAC: Ven 100-400 mg, dose adjusted, d1-21, CDA 5 mg/m 2 d1-5, LDAC 20 mg twice daily d1-10, outside of clinical trials. Cytogenetic and molecular studies were performed at the time of Ven-CDA-LDAC initiation in most cases, by conventional karyotype and next-generation sequencing, respectively. The 2022 European LeukemiaNet (ELN) criteria were applied to define risk and response. Survival was calculated from the time of Ven-CDA-LDAC treatment start to last follow-up or death. Results Patient characteristics A total of 39 RR AML patients (median age 65 years, 67% male, 64% de novo), with prior exposure to Ven-HMA, received Ven-CDA-LDAC (median 1 cycle; range 1-5). Study patients had received one ( n=16), two ( n=14), three ( n=5), four ( n=2), five ( n=1) or nine ( n=1) prior therapies, including Ven-HMA. Nine (23%) patients had relapsed following allogeneic hematopoietic stem cell transplant (AHSCT). ELN cytogenetic risk included intermediate (46%, n=18), and adverse (54%, n=21). Mutations involved TP53 in 9 patients (23%), K/ NRAS in 8 (21%), RUNX1 in 7 (18%), TET2 in 6 (15%), ASXL1 in 5 (13%), and STAG2 in 5 (13%). Response and toxicity Eleven (28%) patients achieved CR ( n=2; 5%) or CRi ( n=9; 23%); median time to response was 1 month and median response duration 3.4 months. In addition, 2 (5%) patients each experienced partial remission (PR) and bone marrow aplasia without fulfilling criteria for morphologic leukemia free state. Measurable residual disease (MRD) was negative by multiparametric flow cytometry in 2 of 7 (29%) informative CR/CRi cases. CR/CRi rates were higher in females (54% vs 15%; p=0.01), de novo vssecondary AML (40% vs 7%; p=0.02), and absence of adverse karyotype (50% vs 9%; p<0.01), K/NRAS (35% vs 0%, p=0.01), ASXL1 (32% vs 0%, p=0.05), or STAG2 mutations (32% vs 0%, p=0.05) (Table 1). Multivariable analysis confirmed superior response in de novo AML (p<0.01), absence of adverse karyotype, (p<0.01), and absence of K/NRAS mutations (p=0.02). CR/CRi rates were not significantly affected by relapsed vs refractory setting ( p=0.95), number of prior therapies ( p=0.51), prior AHSCT ( p=0.64), or TP53 mutations ( p=0.64) (Table 1). Treatment-emergent toxicities included infections (49%, n=19), comprising bacteremia ( n=11), pneumonia ( n=10), peri-rectal abscess ( n=6), and laboratory evidence of tumor lysis syndrome (3%, n=1). Survival At a median follow-up of 3.9 months, from initiation of Ven-CDA-LDAC, 31 deaths (79%), 6 relapses (15%), and 7 AHSCT (18%; including 5 in CR/CRi, 1 in aplasia) were documented. Median survival following Ven-CDA-LDAC was 4.6 months, and superior in the presence vs absence of CR/CRi (8.1 vs 2.9 months; p=0.01), and in patients receiving AHSCT (10.5 vs 3.4 months; p=0.02). Absence of adverse karyotype was also associated with superior survival (6 vs 3.4 months; p=0.05). Multivariable analysis confirmed the favorable survival impact of CR/CRi ( p=0.03) and AHSCT ( p=0.05); survival impact was not apparent for secondary AML ( p=0.29) or K/NRAS ( p=0.70) or TP53 ( p=0.10) mutations. Conclusions The current study suggests transplant bridging value for Ven-CDA-LDAC in AML patients relapsed or refractory to Ven-HMA, especially in the absence of adverse karyotype or K/NRAS mutation. AHSCT and achievement of CR/CRi appear to be indispensable for favorable post-Ven-CDA-LDAC survival.

Background: Core-binding factor acute myeloid leukemia (CBF-AML) is characterized by the presence of inv(16)/t(16;16) or t(8;21), and is classified as favorable risk by the 2022 European LeukemiaNet (ELN) guidelines. High remission rates are observed in the setting of cytarabine- or anthracycline-based induction regimens. The CD33-targeted antibody-drug conjugate gemtuzumab ozogamicin (GO) is FDA-approved for use in newly-diagnosed CD33+ AML; a meta-analysis of 5 prospective randomized studies investigating intensive chemotherapy (IC) +/- GO demonstrated an improved overall survival (OS) with the addition of GO to IC for favorable-risk AML (Hills et al, Lancet Oncol 2014). The trials included in the meta-analysis did not restrict inclusion criteria to CBF-AML alone and there remains variation amongst IC regimens utilized in CBF-AML treatment. In addition, IC combined with the KIT inhibitor dasatinib has shown remission rates and promising overall survival in prospective studies (Paschka et al, Leukemia 2018; Marcucci et al, Blood Adv 2020). We set out to investigate the outcomes of patients (pts) with CBF-AML treated with IC +/- targeted agents (GO or KIT inhibitor) across 5 institutions that are part of the Consortium on Myeloid Malignancies and Neoplastic Diseases (COMMAND). Methods: Retrospective chart review was done to identify pts who were treated with IC with AML harboring inv(16)/t(16;16) or t(8;21) identified on cytogenetics, from January 2010 through April 2023, and were treated across 5 geographically-diverse academic institutions. Pt clinical characteristics, cytogenetics, molecular mutations, treatment, relapse, and OS data were collected. Relapse-free survival (RFS) and OS were both analyzed using Kaplan-Meier analysis. Results: One-hundred forty-nine consecutive pts with CBF-AML were identified, 76 (51%) with inv(16) and 73 (49%) with t(8;21). Median age of pts was 47 years (yrs) (range 18-80yrs), with 64% male pts, and 106 (71%) pts had an ECOG performance status of 0-1. One-hundred seven (72%) pts identified as non-Hispanic White, 22 (15%) identified as non-Hispanic Black, and 12 (8%) identified as Hispanic. Molecular testing via next-generation sequencing was available for 124 pts (83%); 49 (33%) pts had adverse-risk ELN cytogenetics or mutations when excluding CBF status, and 27 (18%) pts harbored KIT mutations. Other baseline pt characteristics are listed in Table 1A. All pts underwent induction with IC; 44 (30%) pts received IC + GO, 21 (14%) received IC + KIT inhibitor (14 received dasatinib, 7 received midostaurin), and the remaining 84 (56%) received IC without a targeted agent. One-hundred fourteen (77%) pts achieved a complete response (CR) to induction therapy, and 1 pt experienced induction-related mortality. Fluorescence in-situ hybridization (FISH) data was available in 82 pts at end of induction with 83% achieving FISH negativity. Measurable residual disease (MRD) testing was done by polymerase chain reaction (PCR) in 62 pts with 76% achieving MRD-negativity. One-hundred forty pts underwent consolidation with a median of 3 cycles of chemotherapy; 21 (15%) pts received GO with consolidation and 17 (12%) received a KIT inhibitor with consolidation. Forty-four (30%) pts underwent allogeneic stem cell transplantation (alloSCT), with 17 in first CR, and 27 after second-line or beyond therapy. With a median follow-up of 22.5 months, the observed 3-yr RFS was 51% (95% CI: 43-61%) and the 3-yr OS was 69% (95% CI: 61-78%). Pts treated with IC + KIT inhibitor had significantly improved 3-yr RFS of 85% (95% CI: 70-100%) compared to other pts, including those who received IC + GO who had a 3-yr RFS of 51% (95% CI: 37-70%) and those who received IC without targeted therapy who had a 3-yr RFS of 45% (95% CI: 35-58%) ( p = 0.02) ( Figure 1). Full survival statistics are shown in Table 1B and Figure 1. Conclusions: In this multi-center retrospective study of pts with CBF-AML undergoing induction with IC regimens with diverse national treatment practices, we find that the addition of GO to IC is not associated with improved outcomes. Pts treated with IC + KIT inhibitor had significantly improved RFS; of note, pts receiving a KIT inhibitor oftentimes continued on maintenance even after consolidation. These data suggest that there may be a role for targeted therapies other than GO to be explored in randomized prospective studies of intensive induction chemotherapy for CBF-AML.

Background : Allogeneic hematopoietic cell transplant (alloHCT) is the only potentially curative therapy for patients (pts) with relapsed or refractory (R/R) AML. Only a minority undergo alloHCT as they typically have dismal outcomes due to high relapse rates, especially those with TP53 mutations and active disease. Additionally, older pts cannot tolerate intensive treatment and hence are not eligible for alloHCT. 131I-apamistamab, an anti-CD45 radioimmunoconjugate, delivers high dose targeted radiation to hematopoietic cells, allowing for myeloablation and eradication of leukemic cells. 131I-apamistamab led induction and conditioning can thus provide these pts access to alloHCT potentially leading to better disease control and outcomes even in pts with the TP53 mutation. Methods: The SIERRA trial (NCT02665065) is a multi-center, randomized, controlled Phase 3 study comparing the rate of durable complete remission (dCR) lasting ≥6 months (mos) after complete remission with/without platelet recovery (CR/CRp) between two groups: 131I-apamistamab led induction and conditioning followed by alloHCT vs physician's choice of conventional care (CC). Pts were randomized (1:1) to CC or 131I-apamistamab with fludarabine and total body irradiation (2 Gy) followed by alloHCT. CR/CRp assessment was 28-56 days post alloHCT or 28-42 days post initiation of therapy in the CC group. Pts in the CC group not achieving leukemia-free state could crossover (CO) to 131I-apamistamab. We report the characteristics and outcomes of all pts with TP53 mutation who were enrolled in the SIERRA trial. Results: In total, 153 pts were randomized (CC, n=77; 131I-apamistamab, n=76). All pts who received the therapeutic dose of 131I-apamistamab (n=66) underwent HCT vs 14 (18.2%) in the CC group. Of evaluable pts, dCR rates at 6 months were 22% in the 131I-apamistamab group vs 0% in the CC group (95% CI;12.29, 34.73; p<0.0001). A total of 37 pts with TP53 mutation were enrolled (CC=20; 131I-apamistamab =17) with a prevalence of 24.2%. Table 1 shows the baseline characteristics of these pts. Median overall survival (OS) for pts in the 131I-apamistamab group, who were TP53 negative was 6.37 mos compared to 5.72 mos for the TP53 mutation positive pts (HR=0.66; 95% CI [0.37, 1.18]; p=0.16). In the CC group (including CO pts), the median OS for TP53 positive pts was 2.96 mos. When the CC group without CO were analyzed, the median OS was 6.51 mos and 1.66 mos for the TP53 mutation negative and positive groups respectively (HR=0.28; 95% CI [0.12, 0.67]; p=0.0022). For TP53 mutation positive pts who received 131I-apamistamab ( 131I-apamistamab plus CO pts), the median OS was 5.49 mos compared to a median 1.66 mos in pts who did not receive 131I-apamistamab (CC pts without CO) [(HR=0.23; 95% CI [0.10, 0.52]; p=0.0002) (Figure 1)]. Conclusion: Pts with TP53 mutated R/R AML have a dismal prognosis and are seldom offered alloHCT due to high post-transplant relapse rates. 131I-apamistamab led alloHCT significantly improves survival outcomes in pts with TP53 mutations, commensurate with rates observed in pts with wildtype TP53, thereby overcoming the negative impact of this mutation. These data clearly support the use of 131I-apamistamab led induction and conditioning and alloHCT in R/R AML, including in patients with a TP53 mutation.

INTRODUCTION: The Stromal Antigen 2 ( STAG2), on Xq25, is the most common cohesin complex gene mutated in myeloid neoplasms (MN) (5-10%). STAG2 mutations ( STAG2m) were incorporated in the ELN2022 as AML-MDS defining genetic mutations inferring poor prognosis and is a genetic marker in IPSS-M risk stratification. The PHD-finger protein 6 ( PHF6) gene, on Xq26.3, is a tumor suppressor gene, mutated in 3% of MN, and is more common in T-ALL. PHF6m is believed to be a late event in MN with little data on its prognostic implications in MN. Both STAG2m and PHF6m are more prevalent in males, but their implications on the clinical presentation of MN have not been compared prior. METHOD: Our study is a multicenter study at Mayo Clinic (Rochester, Florida, Arizona). After IRB approval, we retrospectively analyzed charts of 7935 patients who had NGS between 2016-2022. STAG2m was found in 96 patients, and PHF6m in 116 (including 3 with concurrent STAG2m and PHF6m). We excluded 4 PHF6m patients who had T-ALL. Data was captured at time of NGS. MDS risk stratification was by IPSS-M and AML by ELN2022. Overall survival (OS) was calculated from date of NGS to date of last follow-up. BlueSky Software was used for statistical analysis. RESULTS: Characteristics: We compared 96 STAG2m vs 112 PHF6m MN patients. Of STAG2m cases, 78% were male vs 76% in PHF6m MN. Median age was 72 vs 73 years, respectively. Diagnoses included AML (29% of STAG2m vs 34% of PHF6m MN), MDS (54% vs 28%), MDS/MPN (10% vs 21%) and MPN (3% vs 9%). MDS was more common among STAG2m MN (p<.001) while MDS/MPN was more common among PHF6m MN (=.05). MDS-IB was the most common subtype in both (69% vs 52% in STAG2m vs PHF6m MDS). MDS-LB and 5q subtypes were only found in PHF6m MDS, and there was more PHF6m MDS-RS (13% vs 2%). Median IPSS-M score was 0.9 vs 0.8 in STAG2m vs PHF6m MDS (both high-risk). Majority of STAG2m AML were adverse risk (96%) while PHF6m AML were intermediate (79%) (p<.001). AML cases included 43% vs 30% secondary AML (sAML) in STAG2m vs PHF6m AML. Among STAG2m and PHF6m MN, 17% of each were tMN. Cytogenetic abnormalities were more common in PHF6m MN (50% vs 31%, p=.005). The median bone marrow (BM) blasts count among STAG2m MN was 7% vs 4% in PHF6m MN (p=.03). Genetic characteristics: STAG2m were nonsense, frameshift and splice site (54%, 36% and 11%). PHF6m were nonsense, frameshift, splice site, missense and start loss variant mutations (44%, 33%, 12%, 10% and 1%). The median variant allele frequency (VAF) of STAG2m MN was 50% compared to 32% in PHF6m MN (p=.008). Co-mutations: The median number of co-mutations was 3 in STAG2m and 4 in PHF6m MN (p=.04). The most common were TET2m (37% in STAG2m MN vs 45% in PHF6m MN), RUNX1m (31% in both), SRSF2m (39% vs 20%), ASXL1m (66% vs 38%), BCORm (19% vs 6%), U2AF1m (13% vs 14%) and IDH2m (18% vs 7%). ASXL1m, SRSF2m, BCORm, IDH2m and SF3B1m were more common among STAG2m MN (p=<.001, .003, .006, .02, .09). JAK2m, IDH1m are more common among PHF6m MN (p=.02, .06). Survival: Of STAG2m and PHF6m MN, 70% and 72% of patients received treatment. HSCT was performed in 23 (24%) and 23 (21%) of STAG2m and PHF6m patients, including AML (n=9, n=10), MDS (n=12, n=8), MDS/MPN (n=2, n=2). OS among STAG2m and PHF6m MN was 20.5 and 22.1 months, respectively. OS among AML cases was 13.5 vs 21 months (p=.6) in STAG2m vs PHF6m, was NR vs 22 months (p=.4) in MDS, 11.7 vs 17.6 months in MDS/MPN (p=.4), and 10.4 vs 27.4 months (p=.5) in MPN. There was no difference between males and females in either STAG2m or PHF6m MN. HSCT led to longer OS among both STAG2m (NR vs 19.9 months, p=.01) and PHF6m MN patients (NR vs 17.6 months, p=.07). Among AML patients, HSCT did not significantly impact OS (18 vs 9.6 months, p=.3 and 25.1 vs 21 months, p=.2, in STAG2m and PHF6m). HSCT improved OS in STAG2m MDS (NR vs 20.5 months, p=.03). In PHF6m MDS, OS was 22.1 vs 13.1 months in HSCT vs non-HSCT (p=.3). CONCLUSION: STAG2m and PHF6m are 2 X-linked mutations that occur in MN. Both commonly occur in elderly males. MDS was the most common diagnosis in STAG2m MN. STAG2m co-occurred particularly with SRSF2m ASXL1m and BCORm, which are associated with poor prognosis. In our cohort, STAG2m AML carried a poorer prognosis than PHF6m AML. Our study confirms the ELN2022 AML risk stratification. MDS risk classification and OS did not differ between STAG2m and PHF6m in our cohort. A larger cohort is required to confirm our findings and may provide stronger validation.

Background: It has been recently demonstrated that altered lipid metabolism involving increased free fatty acids (FFAs) uptake supports the growth and proliferation of MM cells (Panaroni et al. Blood 2022; Farell et al. Elife 2023). Whether the availability of FFAs in the bone marrow (BM) microenvironment is associated with the pathogenesis of MM from MGUS has not been previously evaluated. Thus, we evaluated if individual species of FAs or FA-containing lipids such as triacylglycerols (TAGs), diacylglycerols (DAGs), and monoacylglycerols (MAGs) are differentially present between the BM microenvironment of MGUS and MM patients. Methods: Lipid profiles of BM plasma samples (reflective of the BM microenvironment) from patients with a spectrum of plasma cell disorders (22 MGUS and 24 MM (15 newly diagnosed and 9 relapsed/refractory)) were acquired by liquid chromatography (LC)/tandem mass spectrometry (MS), and individual lipid species were quantified based on single-point quantification using 55 isotopically labeled internal standards. Concentration-based lipid species data was analyzed by the web-based tool MetaboAnalyst 5.0. Data was normalized by quantile normalization, log transformed and scaled by Pareto scaling. p values <0.05 were considered significant. Results: A total of 993 distinct lipid species were quantified by the MS-based targeted lipidomics assessment. Of these lipid species, the levels of individual mid-chain (≤50 carbon chain length) and long-chain (≥52 carbon chain length) polyunsaturated TAGs were the most differentially present in the BM plasma of MM compared to MGUS patients (Figure 1A). Even though a principal component analysis (PCA) involving all lipid species showed moderate separation of MM from MGUS patients, five MGUS patients (categorized as MGUS-other (MGO)) who clustered more towards MM patients compared to the remaining MGUS patients had a distinct pattern of individual mid and long-chain polyunsaturated TAG levels that were comparable to MM patients (Figure 1B). Furthermore, the proliferation rate of clonal plasma cells in the BM of these MM and MGUS as measured by the S-phase% was found to be directly correlated with the level of long-chain polyunsaturated TAGs. Conclusions: Mid and long-chain polyunsaturated TAGs are present in lower and higher levels, respectively, in the BM microenvironment of MM compared to MGUS patients. These findings continue to support the importance of FA-containing TAGs and other lipids in the pathogenesis of MM. Future confirmatory studies evaluating the biological significance of these differences are required to determine if they can be exploited for diagnostic and therapeutic purposes.