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PURPOSE Magrolimab is a monoclonal antibody that blocks cluster of differentiation 47, a don't-eat-me signal overexpressed on cancer cells. Cluster of differentiation 47 blockade by magrolimab promotes macrophage-mediated phagocytosis of tumor cells and is synergistic with azacitidine, which increases expression of eat-me signals. We report final phase Ib data in patients with untreated higher-risk myelodysplastic syndromes (MDS) treated with magrolimab and azacitidine (ClinicalTrials.gov identifier: NCT03248479 ). PATIENTS AND METHODS Patients with previously untreated Revised International Prognostic Scoring System intermediate-/high-/very high-risk MDS received magrolimab intravenously as a priming dose (1 mg/kg) followed by ramp-up to a 30 mg/kg once‐weekly or once‐every-2-week maintenance dose. Azacitidine 75 mg/m2 was administered intravenously/subcutaneously once daily on days 1-7 of each 28-day cycle. Primary end points were safety/tolerability and complete remission (CR) rate. RESULTS Ninety-five patients were treated. Revised International Prognostic Scoring System risk was intermediate/high/very high in 27%, 52%, and 21%, respectively. Fifty-nine (62%) had poor-risk cytogenetics and 25 (26%) had TP53 mutation. The most common treatment-emergent adverse effects included constipation (68%), thrombocytopenia (55%), and anemia (52%). Median hemoglobin change from baseline to first postdose assessment was −0.7 g/dL (range, −3.1 to +2.4). CR rate and overall response rate were 33% and 75%, respectively. Median time to response, duration of CR, duration of overall response, and progression-free survival were 1.9, 11.1, 9.8, and 11.6 months, respectively. Median overall survival (OS) was not reached with 17.1-month follow-up. In TP53-mutant patients, 40% achieved CR with median OS of 16.3 months. Thirty-four patients (36%) had allogeneic stem-cell transplant with 77% 2-year OS. CONCLUSION Magrolimab + azacitidine was well tolerated with promising efficacy in patients with untreated higher-risk MDS, including those with TP53 mutations. A phase III trial of magrolimab/placebo + azacitidine is ongoing (ClinicalTrials.gov identifier: NCT04313881 [ENHANCE]).

The acquisition of a multidrug refractory state is a major cause of mortality in myeloma. Myeloma drugs that target the cereblon (CRBN) protein include widely used immunomodulatory drugs (IMiDs), and newer CRBN E3 ligase modulator drugs (CELMoDs), in clinical trials. CRBN genetic disruption causes resistance and poor outcomes with IMiDs. Here, we investigate alternative genomic associations of IMiD resistance, using large whole-genome sequencing patient datasets (n = 522 cases) at newly diagnosed, lenalidomide (LEN)-refractory and lenalidomide-then-pomalidomide (LEN-then-POM)-refractory timepoints. Selecting gene targets reproducibly identified by published CRISPR/shRNA IMiD resistance screens, we found little evidence of genetic disruption by mutation associated with IMiD resistance. However, we identified a chromosome region, 2q37, containing COP9 signalosome members COPS7B and COPS8, copy loss of which significantly enriches between newly diagnosed (incidence 5.5%), LEN-refractory (10.0%), and LEN-then-POM-refractory states (16.4%), and may adversely affect outcomes when clonal fraction is high. In a separate dataset (50 patients) with sequential samples taken throughout treatment, we identified acquisition of 2q37 loss in 16% cases with IMiD exposure, but none in cases without IMiD exposure. The COP9 signalosome is essential for maintenance of the CUL4-DDB1-CRBN E3 ubiquitin ligase. This region may represent a novel marker of IMiD resistance with clinical utility.

The safety and efficacy of combining the IDH1 inhibitor ivosidenib (IVO) with the BCL2 inhibitor venetoclax (VEN; IVO+VEN) +/- azacitidine (AZA; IVO+VEN+AZA) was evaluated in four cohorts of patients with IDH1-mutated myeloid malignancies (n=31). Most (91%) adverse events were grade 1 or 2. The maximal tolerated dose was not reached. Composite complete remission with IVO+VEN+AZA vs. IVO+VEN was 90% vs. 83%. Among MRD-evaluable patients (N=16) 63% attained MRD-negative remissions; IDH1 mutation clearance occurred in 64% of patients receiving ≥5 treatment cycles (N=14). Median EFS and OS were 36 (95% CI: 23-NR) and 42 (95% CI: 42-NR) months. Patients with signaling gene mutations appeared to particularly benefit from the triplet regimen. Longitudinal single-cell proteogenomic analyses linked co-occurring mutations, anti-apoptotic protein expression, and cell maturation to therapeutic sensitivity of IDH1-mutated clones. No IDH isoform switching or second-site IDH1 mutations were observed, indicating combination therapy may overcome established resistance pathways to single-agent IVO.

Supplementary Table 1. Study stratification and dosing regimen; Supplementary Table 2. p53 target genes examined in this study; Supplementary Table 3. Characteristics of evaluable patients treated at the MTD; Supplementary Table 4. Patient demographic data by cohort; Supplementary Table 5. Adverse events by grade observed in > 10% of the patients/stratum; Supplementary Table 6. Stratum pharmacokinetic parameters based on RG7112 dose regimen and formulation; Supplementary Table 7. Summary of steady state AUC for AML patients treated at the MTD; Supplementary Table 8. Clinical activity for patients with p53 mutations

Table S3. Variants detected by NGS targeted re-sequencing

The following information describes additional study design criteria and safety considerations used in the phase 1 clinical trial of RG7112 in patients with hematological malignancies

Supplementary Fig. 1. Day 10 dose-mean PK profiles in patients with leukemia; Supplementary Figure 2. RG7112 induces p53-mediated apoptosis in circulating lymphoma cells from a patient with SLL/CLL (810 mg to 1500 mg BID)

Table S1. Details for NGS amplicons

Purpose: RG7112 is a small-molecule MDM2 antagonist. MDM2 is a negative regulator of the tumor suppressor p53 and frequently overexpressed in leukemias. Thus, a phase I study of RG7112 in patients with hematologic malignancies was conducted.Experimental Design: Primary study objectives included determination of the dose and safety profile of RG7112. Secondary objectives included evaluation of pharmacokinetics; pharmacodynamics, such as TP53-mutation status and MDM2 expression; and preliminary clinical activity. Patients were divided into two cohorts: Stratum A [relapsed/refractory acute myeloid leukemia (AML; except acute promyelocytic leukemia), acute lymphoblastic leukemia, and chronic myelogenous leukemia] and Stratum B (relapsed/refractory chronic lymphocytic leukemia/small cell lymphocytic leukemia; CLL/sCLL). Some Stratum A patients were treated at the MTD to assess clinical activity.Results: RG7112 was administered to 116 patients (96 patients in Stratum A and 20 patients in Stratum B). All patients experienced at least 1 adverse event, and 3 dose-limiting toxicities were reported. Pharmacokinetic analysis indicated that twice-daily dosing enhanced daily exposure. Antileukemia activity was observed in the 30 patients with AML assessed at the MTD, including 5 patients who met International Working Group (IWG) criteria for response. Exploratory analysis revealed TP53 mutations in 14% of Stratum A patients and in 40% of Stratum B patients. Two patients with TP53 mutations exhibited clinical activity. p53 target genes were induced only in TP53 wild-type leukemic cells. Baseline expression levels of MDM2 correlated positively with clinical response.Conclusions: RG7112 demonstrated clinical activity against relapsed/refractory AML and CLL/sCLL. MDM2 inhibition resulted in p53 stabilization and transcriptional activation of p53-target genes. We provide proof-of-concept that MDM2 inhibition restores p53 function and generates clinical responses in hematologic malignancies. Clin Cancer Res; 22(4); 868–76. ©2015 AACR.

Table S2. Details of Exons covered Table S4. Details of antibodies/ streptavidin used Table S5. Summary of longitudinal progenitor LSC quantitation by FACS Table S6. Overview of toxicities Figure S1. Progenitor LSC FACS gating strategy Figure S2. Kaplan-Meier plot for duration of response Figure S3. Forest plot of sub group analysis in overall response rate and overall survival.

Purpose: Azacitidine (AZA) is a novel therapeutic option in older patients with acute myeloid leukemia (AML), but its rational utilization is compromised by the fact that neither the determinants of clinical response nor its mechanism of action are defined. Co-administration of histone deacetylase inhibitors, such as vorinostat (VOR), is reported to improve the clinical activity of AZA, but this has not been prospectively studied in patients with AML.Experimental Design: We compared outcomes in 259 adults with AML (n = 217) and MDS (n = 42) randomized to receive either AZA monotherapy (75 mg/m2 × 7 days every 28 days) or AZA combined with VOR 300 mg twice a day on days 3 to 9 orally. Next-generation sequencing was performed in 250 patients on 41 genes commonly mutated in AML. Serial immunophenotyping of progenitor cells was performed in 47 patients.Results: Co-administration of VOR did not increase the overall response rate (P = 0.84) or overall survival (OS; P = 0.32). Specifically, no benefit was identified in either de novo or relapsed AML. Mutations in the genes CDKN2A (P = 0.0001), IDH1 (P = 0.004), and TP53 (P = 0.003) were associated with reduced OS. Lymphoid multipotential progenitor populations were greatly expanded at diagnosis and although reduced in size in responding patients remained detectable throughout treatment.Conclusions: This study demonstrates no benefit of concurrent administration of VOR with AZA but identifies a mutational signature predictive of outcome after AZA-based therapy. The correlation between heterozygous loss of function CDKN2A mutations and decreased OS implicates induction of cell-cycle arrest as a mechanism by which AZA exerts its clinical activity. Clin Cancer Res; 23(21); 6430–40. ©2017 AACR.

Induction of differentiation is a promising therapeutic strategy against acute myeloid leukemia. However, current differentiation therapies are effective only to specific patient populations. To identify novel differentiation agents with wider efficacy, we developed a phenotypic high-throughput screen with a range of genetically diverse cell lines. From the resulting hits, one chemical scaffold was optimized in terms of activity and physicochemical properties to yield OXS007417, a proof-of-concept tool compound, which was also able to decrease tumor volume in a murine in vivo xenograft model.

Context: Pivekimab sunirine (PVEK, IMGN632) is a first-in-class ADC comprising a CD123 high-affinity antibody, a cleavable linker, and an IGN (indolinobenzodiazepine pseudodimer) payload. PVEK with azacitidine (AZA) and venetoclax (VEN) is a novel triplet that has demonstrated anti-leukemia activity in relapsed/refractory AML patients. Objective: Evaluate the anti-leukemia activity in genetic subgroups of AML and safety of the triplet. Intervention: Patients with relapsed/refractory AML received PVEK+AZA+VEN in a three-drug escalation over a 28-day cycle: PVEK 0.015 or 0.045 mg/kg day 7, AZA 50 or 75 mg/m2 days 1–7, and VEN 400 mg for 8, 14, or 21 days. Results: Twenty-nine patients (median age 67 y, ELN adverse 62%, prior VEN 48%) were in higher-intensity cohorts (PVEK 0.045 mg/kg and/or VEN for 14 or 21 days). The overall response rate (ORR) was 59% (4 CR, 6 CRh, 1 CRp, 6 MLFS) and the composite complete remission rate (CCR, CR+CRh+CRp+CRi) was 38%. Higher rates are seen in patients with FLT3-ITD (n=9, ORR 89%, CCR 78%), IDH2 (n=4, ORR 75%, CCR 75%), and WT1 (n=7, ORR 57%, CCR 43%) mutations. Lower rates are seen in patients with monosomy 7/abn7q (n=6, ORR 17%, CCR 17%), TP53 (n=4, ORR 25%, CCR 25%), and ASXL1 (n=6, ORR 67%, CCR 17%) deletions or mutations. The safety profile for the PVEK triplet is similar to AZA+VEN. No VOD, TLS, or CRS was reported. IRRs were reported in 33% (n=17, one grade 4) of patients given 1 dose of dexamethasone (8 mg) as premedication (n=51); these IRRs were most frequently tachycardia and chills, with no anaphylactic reactions reported. Following the data cut-off, there was a second grade 4 IRR, and the prophylactic regimen was increased with two additional doses of dexamethasone on the day prior to the PVEK dose. The IRR rate has dropped to 8% (3 of 38), with no grade 3+; all were grades 1–2 that resolved with limited intervention (P Conclusions: The PVEK triplet with AZA+VEN demonstrates anti-leukemic activity across multiple high-risk genetic subsets of relapsed/refractory AML. Prophylactic steroids added on day –1 have significantly reduced IRRs. Expansion cohorts are now enrolling for untreated and relapsed AML patients (NCT04086264).

BACKGROUND: IDH2 mutations occur in 8-19% of patients (pts) with AML. ENA is an oral, selective IDH2 inhibitor and AZA is a hypomethylating agent. In a phase 1b/2 trial, combination therapy with ENA + SC AZA significantly improved overall response rate (ORR) and complete remission (CR) rate vs AZA monotherapy (AZA-only) (P = 0.0064 and P = 0.0001, respectively) in pts with newly diagnosed (ND), mutant-IDH2 (m IDH2) AML not eligible for IC (DiNardo, 2020). Injectable AZA has shown to maintain pt-reported health-related quality of life (HRQoL) in ND-AML (Dombret, 2014); the effect of ENA on HRQoL has not been reported. While morphologic responses are associated with improved HRQoL, combining active agents could increase toxicity, which could diminish HRQoL. OBJECTIVE: Assess pt-reported HRQoL outcomes during treatment (Tx) with ENA + AZA and AZA-only in the phase 1b/2 AG-221-AML-005 trial (NCT02677922). METHODS: Adult pts with ECOG PS ≤ 2 and intermediate- or poor-risk cytogenetics were enrolled. In the phase 2 portion, pts were randomized 2:1 to ENA 100-mg QD (continuous) + AZA 75 mg/m 2/day (d) SC × 7d, or to AZA-only, in repeated 28d cycles (C). Pt-reported HRQoL was assessed during Tx using the EORTC QLQ-C30 and EQ-5D-5L instruments, each completed at baseline (BL [C1D1]), on d1 of each Tx cycle, and end of Tx (EOT). The primary HRQoL measures were observed mean changes from BL (CFB) in 5 QLQ-C30 domains-Global Health status (GHS)/QoL, Physical Functioning (PF), Role Functioning (RF), Fatigue, and Dyspnea-each scored from 0-100, with higher scores indicating better QoL or functioning but worse symptomology. Changes in the remaining 10 QLQ-C30 domains, and in the EQ-5D-5L utility index (UI) score (derived via cross-walk to EQ-5D-3L based on UK population weights) and EQ-5D visual analogue scale (VAS) score (0-100) were secondary outcomes. Changes are reported for Tx cycles with ≥ 10 evaluable pts in each Tx arm. Clinically meaningful changes were defined as mean CFB of ≥ 10 points on any QLQ-C30 domain, ≥ 0.08 point on the EQ-5D-5L UI, and ≥ 7 points on the EQ-5D VAS. HRQoL-evaluable pts had an evaluable assessment (≥ 15 items on the QLQ-C30; all 5 EQ-5D-5L items; non-missing EQ-5D VAS) at BL and at ≥ 1 post-BL visit. RESULTS: The HRQoL-evaluable population comprised ~75% of pts randomized to either ENA+AZA (51/68) or AZA-only (25/33); 25 pts were not evaluable due to missing data at BL (n = 16) and/or no post-BL visit (n = 19). QLQ-C30 data were missing for ~20%-30% of eligible pts at almost all post-BL visits through C9D1 (the last visit with ≥ 10 pts in each Tx arm), and for ≥ 50% of pts at the EOT visit; similar rates were observed on the EQ-5D-5L. BL characteristics for HRQoL-evaluable pts were generally comparable between arms and similar to those of the ITT population. At BL, mean QLQ-C30 scores in each Tx arm were meaningfully worse than general population normative scores across the majority of QLQ-C30 domains, including all 5 domains of primary interest, and on the EQ-5D VAS. During early ENA+AZA Tx cycles, observed mean QLQ-C30 scores remained similar to BL in the GHS/QoL and Dyspnea domains, and were worsened from BL in the PF, RF, and Fatigue domains-but reached the threshold for meaningful worsening only in the RF domain and only at C3D1 (Figure). Domain scores then trended toward improvement over time, with clinically meaningful improvements from BL from C4-C9 in the Dyspnea domain, C5-C9 in the GHS/QoL and Fatigue domains (except at C7 for Fatigue), and from C8-C9 in the RF domain; mean scores also improved from BL in the PF domain but were not clinically meaningful at any visit. Similar trends were observed in the AZA-only arm but without the early worsening seen with ENA+AZA (Figure). There were no clinically meaningful or statistically significant differences between Tx arms in mean CFB for any of the primary QLQ-C30 domains through C9. In both Tx arms, mean score CFB in the secondary QLQ-C30 domains, EQ-5D-5L UI, and EQ-5D VAS followed similar trends of improvement over time among pts who remained on Tx. CONCLUSIONS: At BL, these pts with AML reported meaningfully worse HRQoL scores across the majority of the QLQ-C30 domains and the EQ-5D VAS compared with the general population, indicating substantial impairment in HRQoL, functioning, and symptoms. HRQoL scores generally worsened during early ENA+AZA Tx cycles, but then improved with continued Tx, with meaningful improvement across multiple measures during later Tx cycles. Figure 1 Figure 1. Disclosures DiNardo: Agios/Servier: Consultancy, Honoraria, Research Funding; Foghorn: Honoraria, Research Funding; AbbVie: Consultancy, Research Funding; Forma: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Celgene, a Bristol Myers Squibb company: Honoraria, Research Funding; Novartis: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Takeda: Honoraria; Notable Labs: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; ImmuneOnc: Honoraria, Research Funding. Dohner: Pfizer: Research Funding; Roche: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; GEMoaB: Honoraria; Janssen: Honoraria; Helsinn: Honoraria; Gilead: Honoraria; Berlin-Chemie: Honoraria; Astex Pharmaceuticals: Honoraria; Astellas: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Agios: Honoraria, Research Funding; AstraZeneca: Honoraria; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Oxford Biomedica: Honoraria; Abbvie: Honoraria, Research Funding. Zeidan: Agios: Consultancy; AstraZeneca: Consultancy; BioCryst: Other: Clinical Trial Committees; Daiichi Sankyo: Consultancy; Genentech: Consultancy; Cardiff Oncology: Consultancy, Other: Travel support, Research Funding; Incyte: Consultancy, Research Funding; Janssen: Consultancy; Novartis: Consultancy, Other: Clinical Trial Committees, Travel support, Research Funding; Pfizer: Other: Travel support, Research Funding; Amgen: Consultancy, Research Funding; Ionis: Consultancy; Gilead: Consultancy, Other: Clinical Trial Committees; Astellas: Consultancy; BMS: Consultancy, Other: Clinical Trial Committees, Research Funding; Geron: Other: Clinical Trial Committees; Acceleron: Consultancy, Research Funding; Loxo Oncology: Consultancy, Other: Clinical Trial Committees; Kura: Consultancy, Other: Clinical Trial Committees; Boehringer Ingelheim: Consultancy, Research Funding; Aprea: Consultancy, Research Funding; Jasper: Consultancy; Epizyme: Consultancy; Jazz: Consultancy; ADC Therapeutics: Research Funding; BeyondSpring: Consultancy; Astex: Research Funding; AbbVie: Consultancy, Other: Clinical Trial Committees, Research Funding. Schuh: Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics: Research Funding; Kite/Gilead: Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vyas: Gilead: Honoraria; Jazz: Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Takeda: Honoraria; Astellas: Consultancy, Honoraria; Pfizer: Honoraria; Daiichi Sankyo: Honoraria; Janssen: Honoraria; AbbVie: Consultancy, Honoraria. Stein: Janssen Pharmaceuticals: Consultancy; Abbvie: Consultancy; Gilead Sciences, Inc.: Consultancy; Blueprint Medicines: Consultancy; Foghorn Therapeutics: Consultancy; Jazz Pharmaceuticals: Consultancy; Bristol Myers Squibb: Consultancy; Celgene: Consultancy; PinotBio: Consultancy; Daiichi Sankyo: Consultancy; Syros Pharmaceuticals, Inc.: Consultancy; Genentech: Consultancy; Syndax Pharmaceuticals: Consultancy; Agios Pharmaceuticals, Inc: Consultancy; Astellas: Consultancy; Novartis: Consultancy. Wei: Novartis, Abbvie, Celgene/BMS: Speakers Bureau; Abbvie, Amgen, Astellas, AstraZeneca, Celgene/BMS, Genentech, Janssen, MacroGenics, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees; Former employee of Walter and Eliza Hall Institute: Patents & Royalties: Prof. Andrew Wei is a former employee of the Walter and Eliza Hall Institute and is eligible for a fraction of the royalty stream related to Venetoclax; Abbvie, Amgen, AstraZeneca, Celgene/BMS, Novartis, Servier and F. Hoffmann-La Roche: Research Funding; Abbvie, Amgen, Astellas, AstraZeneca, Celgene/BMS, Genentech, Janssen, MacroGenics, Novartis, Pfizer, and Servier: Honoraria; Servier: Consultancy. de Botton: Celgene: Consultancy; Agios: Consultancy, Honoraria; Forma: Consultancy, Honoraria; Astellas: Consultancy; Abbvie: Consultancy; Daiichi: Consultancy; Novartis: Consultancy; Jazz: Consultancy; Pfizer: Consultancy. Chen: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Lord-Bessen: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Martin-Regueira: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Lersch: Celgene, a Bristol-Myers Squibb Company: Current Employment. Gong: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Guo: Bristol Myers Squibb: Consultancy; Daiichi Sankyo: Consultancy; UCB: Consultancy; Janssen: Consultancy; Gilead: Consultancy; EMD Serono: Consultancy; Evidera: Current Employment. Shi: Bristol Myers Squibb: Consultancy. Montesinos: Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Stemline/Menarini: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Glycomimetics: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau.

Background: Magrolimab (Hu5F9-G4) is an antibody blocking CD47, a macrophage immune checkpoint and "don't eat me" signal on cancer cells, that eliminates leukemia stem cells by inducing tumor phagocytosis. Hypomethylating agents synergize with magrolimab by inducing "eat me" signals on leukemic blasts, thereby enhancing phagocytosis. Magrolimab with azacitidine (AZA) has shown encouraging activity in frontline acute myeloid leukemia (AML) unfit for intensive chemotherapy and myelodysplastic syndrome. In TP53-mutant (TP53m) AML, it demonstrated an objective response rate of 69%, complete response (CR) rate of 45%, and median overall survival (OS) of 12.9 months. The TP53 gene mutation is observed in approximately 10-15% of newly diagnosed AML and is associated with poor survival. The published first-line median OS in TP53m AML is 5-7 months, regardless of whether patients are treated with intensive chemotherapy or non-intensive approaches, such as a hypomethylating agent with venetoclax (VEN). AML patients harboring the TP53 gene mutation represent a significant unmet medical need. Aims: To evaluate the efficacy, safety, and tolerability of magrolimab+AZA vs physician's choice of VEN+AZA or "7+3" chemotherapy in patients with previously untreated TP53m AML. Design and Methods: This is a phase 3, randomized, open-label, multicenter study. Approximately 346 patients will be randomized (1:1) to magrolimab+AZA (investigational arm) or physician's choice of VEN+AZA or 7+3 chemotherapy, based on patient fitness (NCT04778397). Randomization will be stratified by appropriateness for non-intensive vs intensive therapy, geographic region (US vs non-US sites), and age ( Status: Patients will be enrolled at approximately 140 centers globally. Accrual is ongoing. Disclosures Daver: Gilead Sciences, Inc.: Consultancy, Research Funding; ImmunoGen: Consultancy, Research Funding; Glycomimetics: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding; Novimmune: Research Funding; Genentech: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Sevier: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Hanmi: Research Funding; Trovagene: Consultancy, Research Funding; FATE Therapeutics: Research Funding; Trillium: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy, Other: Data Monitoring Committee member; Dava Oncology (Arog): Consultancy; Celgene: Consultancy; Syndax: Consultancy; Shattuck Labs: Consultancy; Agios: Consultancy; Kite Pharmaceuticals: Consultancy; SOBI: Consultancy; STAR Therapeutics: Consultancy; Karyopharm: Research Funding; Newave: Research Funding. Vyas: Novartis: Honoraria; AbbVie: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Gilead: Honoraria; Jazz: Honoraria; Janssen: Honoraria; Pfizer: Honoraria; Daiichi Sankyo: Honoraria; Takeda: Honoraria. Chao: Gilead Sciences, Inc.: Current Employment; TigaTx: Membership on an entity's Board of Directors or advisory committees; Stanford University: Patents & Royalties; Hepatx Inc: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Iconovir Bio: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; Stanford University Medical School: Membership on an entity's Board of Directors or advisory committees; Foresite capital: Consultancy; Bioverge: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Chimera Bioengineering: Current equity holder in publicly-traded company. Xing: Gilead Sciences, Inc.: Current Employment. Renard: Gilead Sciences, Inc.: Current Employment, Current holder of individual stocks in a privately-held company; Alphabet: Current Employment, Current equity holder in publicly-traded company. Ramsingh: Gilead Sciences, Inc.: Current Employment, Current holder of individual stocks in a privately-held company. Sallman: Syndax: Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Speakers Bureau; Aprea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Magenta: Consultancy; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees; Intellia: Membership on an entity's Board of Directors or advisory committees. Wei: Prof. Andrew Wei is a former employee of the Walter and Eliza Hall Institute and is eligible for a fraction of the royalty stream related to Venetoclax: Patents & Royalties; MacroGenics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche AG: Research Funding; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: Magrolimab is an investigational therapy