Untreated Acute Myeloid Leukemia Research Articles

Efficacy and safety of venetoclax-based combination therapy for previously untreated acute myeloid leukemia: a meta-analysis

ABSTRACT Purpose: To explore the efficacy and safety of venetoclax-based combination therapy for older patients with newly diagnosed acute myeloid leukemia (AML). Methods: We performed a systematic review and meta-analysis of clinical trials comparing venetoclax plus hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) with mono-HMAs or LDAC. The random or fixed effects model was applied to the studies based on heterogeneity. Dichotomous data were summarized using the risk ratio (RR) and 95% confidence interval (CI). Continuous variable data were reported as weighted mean differences (WMDs). Results: Nine studies, including a total of 1232 patients, were included in this meta-analysis. Thec complete remission (CR)/complete remission with incomplete hematological recovery (CRi) rate of the venetoclax (Ven) + azacytidine (Aza) group was significantly greater than that of the Aza monotherapy group (RR: 2.42; 95% CI: 1.85–3.15; P < 0.001). Similarly, the CR/CRi rate of the Ven + LDAC group was also significantly greater than that of the LDAC monotherapy group (RR: 2.57; 95% CI: 1.58–4.17; P = 0.00). The same results were observed for OS among these groups. However, the incidence of febrile neutropenia was greater in the Ven + Aza group than in the Ven + Decitabine (Dec) or monotherapy Aza group (RR: 0.69; 95% CI: 0.53–0.90; P = 0.006 and RR: 2.19; 95% CI: 1.58–3.03; P < 0.001, respectively). In addition, the Ven + LDAC group had significantly greater rates of constipation, diarrhea, nausea, and vomiting than the LDAC monotherapy group, with RRs and CIs of 0.61 (95% CI 0.44–0.83, P = 0.002), 1.81 (95% CI 1.22–2.67, P = 0.003), 1.39 (95% CI 1.06–1.82, P = 0.016), and 1.80 (95% CI 1.19–2.72, P = 0.005), respectively. Conclusion: Venetoclax combined with azacitidine, decitabine, or LDAC significantly improved the CR/CRi and OS of patients with previously untreated AML. However, venetoclax plus azacitidine or LDAC was more likely to lead to increased febrile neutropenia and gastrointestinal toxicity.

Efficacy of Venetoclax and Azacitidine in Acute Myeloid Leukemia Compared to Azacitidine Monotherapy: Real-World Experience.

The combination of venetoclax (VEN) and azacitidine (AZA) (VEN+AZA) leads to higher complete remission rates and longer overall survival (OS) in patients with untreated acute myeloid leukemia (AML) who are ineligible for intensive combination chemotherapy. In practice, the doses of VEN and AZA are reduced at the attending physician's discretion to avoid adverse events; however, the impact of dose and duration reductions has not been fully clarified. We analyzed whether the efficacy was maintained with reduced VEN+AZA compared to AZA monotherapy in the real world. A total of 33 patients were included; 17 (10 newly diagnosed, 7 primary refractory or relapsed) received VEN+AZA, and 16 (7 newly diagnosed, 9 primary refractory or relapsed) received AZA. We analyzed complete remission (CR) and CR with incomplete hematologic recovery (CRi) rates, OS, and the incidence of adverse events. CR/CRi were achieved in 7/17 (41.2%) and 11/17 (64.7%) patients in the VEN+AZA group and 0/15 (0%) and 2/15 (6.7%) patients in the AZA group, respectively. The CR/CRi rate was higher in the VEN+AZA group than in the AZA group (p=0.001). OS was longer in the VEN+AZA group than in the AZA group (p=0.03), with a median of 506 days [95% confidence interval (CI)=234-585 days] and 208 days (95% CI=52-343 days), respectively. The doses of the VEN+AZA combination were reduced at the attending physician's discretion, resulting in a higher CR/CRi rate and longer OS than AZA monotherapy and is considered useful for AML in the real world.

Glasdegib with intensive/nonintensive chemotherapy in Japanese patients with untreated acute myeloid leukemia or high-risk myelodysplastic syndromes.

Glasdegib is a potent, selective, oral inhibitor of the hedgehog signaling pathway. In this phase I study, previously untreated Japanese patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes were treated with glasdegib (100 mg once daily) combinations: low-dose cytarabine (20 mg twice daily; cohort 1, n = 6; expansion cohort, n = 15); daunorubicin and cytarabine (60 mg/m2 i.v.; cohort 2, n = 6); or azacitidine (100 mg/m2 i.v.; cohort 3, n = 6). Patients, except cohort 2, were ineligible for intensive chemotherapy. The primary end-point was dose-limiting toxicity in cohorts 1-3 and disease-modifying response in the expansion cohort. Disease-modifying response rate was tested with the null hypothesis of 6.8%, which was set based on the results from the phase II BRIGHT AML 1003 study (NCT01546038). No dose-limiting toxicities were observed in cohorts 1 or 3; one patient in cohort 2 experienced a dose-limiting toxicity of grade 3 erythroderma. The most common grade ≥3 treatment-related adverse events were neutropenia and thrombocytopenia (66.7% each) in cohort 1 and thrombocytopenia (60.0%) in the expansion cohort. In the expansion cohort, the disease-modifying response rate was 46.7% (90% confidence interval, 24.4-70.0; p < 0.0001), with all patients achieving either a complete response or complete response with incomplete blood count recovery. Median overall survival was 13.9 months. In this study, the primary disease-modifying response end-point with glasdegib plus low-dose cytarabine was met. The study confirms the safety and efficacy of glasdegib plus low-dose cytarabine in Japanese patients with AML ineligible for intensive chemotherapy.

Differential co-expression network analysis elucidated genes associated with sensitivity to farnesyltransferase inhibitor and prognosis of acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous disease and the most common form of acute leukemia with a poor prognosis. Due to its complexity, the disease requires the identification of biomarkers for reliable prognosis. To identify potential disease genes that regulate patient prognosis, we used differential co-expression network analysis and transcriptomics data from relapsed, refractory, and previously untreated AML patients based on their response to treatment in the present study. In addition, we combined functional genomics and transcriptomics data to identify novel and therapeutically potential systems biomarkers for patients who do or do not respond to treatment. As a result, we constructed co-expression networks for response and non-response cases and identified a highly interconnected group of genes consisting of SECISBP2L, MAN1A2, PRPF31, VASP, and SNAPC1 in the response network and a group consisting of PHTF2, SLC11A2, PDLIM5, OTUB1, and KLRD1 in the non-response network, both of which showed high prognostic performance with hazard ratios of 4.12 and 3.66, respectively. Remarkably, ETS1, GATA2, AR, YBX1, and FOXP3 were found to be important transcription factors in both networks. The prognostic indicators reported here could be considered as a resource for identifying tumorigenesis and chemoresistance to farnesyltransferase inhibitor. They could help identify important research directions for the development of new prognostic and therapeutic techniques for AML.

Venetoclax-Based Therapy before Allogeneic Hematopoietic Cell Transplantation for Acute Myeloid Leukemia

Introduction The BCL-2 inhibitor venetoclax (VEN) is effective in older patients with untreated acute myeloid leukemia (AML). Few reports exist on the use of VEN as a bridging therapy for allogeneic hematopoietic cell transplantation (HCT) for AML. Previous studies have shown that NPM1 and IDH2 gene mutations are associated with high response rates to VEN therapy. We performed a retrospective cohort study to analyze the efficacy of VEN-based bridging therapy before HCT. Methods We included 46 patients who were eligible for HCT and received bridging therapy combined with VEN between April 2021 and June 2023 at our center. We evaluated response rates to VEN and HCT outcomes. None of the patients received VEN prior to the study. The response rate to VEN was evaluated using the 2022 European LeukemiaNet (ELN) criteria. We estimated overall survival (OS) using the Kaplan-Meier method, log-rank test, and Gray's test for univariate analysis of cumulative incidence of relapse (CIR) and non-relapse mortality (NRM). We used the Cox proportional hazards model for a multivariate analysis of OS. We extracted DNA from the bone marrow or peripheral blood, and analyzed gene mutations using next-generation sequencing (NGS), targeting 70 genes known to be recurrently mutated in myeloid malignancies. Results Of the 46 patients, 32 had de novo AML, 7 had de novo MDS/AML, 5 had secondary AML, 1 had secondary MDS/AML, and 1 had myeloid sarcoma. The median age was 59 (21-70) years. Nineteen were women and 7 had a history of HCT. The regimens combined with VEN were azacitidine in 39 cases and low-dose cytarabine in 7. According to the 2022 ELN risk classification by genetics at diagnosis, 7 were favorable, 11 were intermediate, and 27 were at adverse risk. Nine patients were in hematological complete remission (CR) / CR with incomplete count recovery (CRi) while 37 were not, when VEN was initiated. The maximum response rates among the patients who started VEN treatment in the non-CR group were: 18 with CR/CRi (49%) and no response in 19 (51%). The median time from the first dose of VEN to HCT was 70 (27-315) days. Forty-one patients underwent HCT and 19 (43%) were in CR/CRi at HCT. The reasons for discontinuation of VEN were HCT in 34 cases, failure in 9, and adverse events in 4 (hematological toxicity in 3 cases and infection in 1). Sixteen patients died due to primary disease (n=9), infection (n=5), thrombotic microangiopathy (n=1), and multi-organ failure (n=1). The median post-HCT observation period of survivors was 156 (25-775) days, and at 1-year after HCT, OS was 49.6% (95% CI: 28.0-67.9), CIR was 40.6% (95% CI: 24.1-56.6) and NRM was 15.2% (95% CI: 5.5-29.5). At 1-year after HCT, outcomes of the patients who were in CR/CRi at HCT was better than that of those who were not (OS, 80.8% vs. 26.4%, p=0.002; CIR, 13.4% vs. 61.8%, p&amp;lt;0.01; NRM, 0% vs. 26.7%, p&amp;lt;0.05). In 35 of the patients who underwent the first HCT, the 1-year OS was 88.9% in those who were in CR and 36.5% in those who were not (p=0.015). Thirty cases were non-CR at the start of the VEN regimen prior to their first HCT. This group had a 1-year OS of 57.8% (95% CI, 27.4-79.3). In 11 patients who achieved CR before HCT and 18 others who did not, the 1-year OS rates were 83.3% and 39.9%, respectively (p=0.10). Genetic analysis was performed by NGS in 37 patients before starting VEN, revealing mutations in TP53 (n=9), RUNX1 (n=7), IDH1 (n=6), ASXL1 (n=6), and DNMT3A (n=6) (Fig. 1A). Alterations in MDS-related genes (n=20) and kinase-related genes ( KIT, PTPN11, FLT3, KRAS, n=11) were frequent. Among the patients receiving their first HCTs, the 1-year OS was 0% in the group with TP53 mutations, and 63.9% in the wild-type TP53 group (p=0.04). The OS was worse in patients with mutated TP53 or kinase-related genes (n=19) than those without either mutation (n=15) (Fig. 1B, 1-year OS 28.7% vs. 72.9%, p=0.029). A multivariate analysis of OS revealed that patients who were not in CR at HCT (HR, 25.01 [95% CI, 2.406-259.9], p=0.007), those who previously underwent HCT (HR, 36.81 [95% CI, 4.599-294.7], p=0.035), and those with TP53 or kinase-related gene mutations (HR, 6.311 [95% CI, 1.137-350.0], p=0.035) had significantly lower OS rates. There was no significant difference in OS between the different ELN risk categories. Conclusions Non-CR at the time of HCT, a history of HCT, and mutations in TP53 or kinase-related genes were found to be independent poor prognostic factors for OS after VEN-based bridging treatment followed by HCT.

Safety, Pharmacodynamic, and Anti-Tumor Activity of SL-172154 As Monotherapy and in Combination with Azacitidine (AZA) in Relapsed/Refractory (R/R) Acute Myeloid Leukemia (AML) and Higher-Risk Myelodysplastic Syndromes/Neoplasms (HR-MDS) Patients (pts)

Background: CD47 blocking antibodies and SIRPα-Fc fusion proteins have demonstrated activity in combination with azacitidine (AZA) in previously untreated (UnTx) HR-MDS and AML pts. SL-172154 (SIRPα-Fc-CD40L), a hexameric, bi-functional fusion protein consisting of SIRPα domains linked to CD40L domains through an inert Fc linker demonstrated improved anti-tumor activity in comparison to naked CD47 blocking antibodies in pre-clinical studies [de Silva et al. Cancer Immunol Res 2020]. SL-172154, as a CD47 inhibitor, requires combination with AZA to enhance pro-phagocytic signals on leukemic stem cells/blasts thereby potentiating macrophage phagocytosis in AML/HR-MDS. Here we report the results from the Phase 1 Dose Escalation. cohorts for SL-172154 monotherapy [SL-mono] and for SL-172154 + AZA combination [SL-AZA] in pts with HR-MDS or AML. Methods: The objectives of the dose escalation cohorts include evaluation of safety, dose-limiting toxicity (DLT), recommended phase 2 dose, pharmacokinetic and pharmacodynamic effects and efficacy per IWG 2006 for MDS and ELN 2017 for AML. SL-172154 was administered IV weekly of a 28-day cycle as monotherapy or with AZA 75 mg/m 2 for 7 days per cycle. mTPI-2 was used for dose escalation with a DLT threshold of 20%. Pts ≥ 18 years old with R/R HR-MDS or R/R AML were eligible for dose escalation cohorts. In addition, UnTx pts with TP53 mutant (TP53m)-MDS were eligible for SL-AZA cohorts. Results: As of May 25, 2023, 37 pts were enrolled (19 in SL-mono; 18 in SL-AZA cohorts): 14 women; median age 70 years [range 44-81]. 27 pts had R/R AML (16 de novo; 11 secondary), 5 had R/R MDS, and 5 were UnTx TP53m-MDS. 23 (85%) of 27 R/R AML pts had adverse genetic abnormalities per 2017 ELN classification, including 9 (33%) with TP53m or del 17. The median number of prior lines of AML therapy was 2 [range 1-4]; 25 (93%) had received venetoclax (VEN) and 23 (85%) had received a hypomethylating agent (HMA). All 5 pts with R/R MDS had previously received HMA and 2 pts were previously treated with VEN. SL-172154 was dose escalated as monotherapy or with AZA as shown in Table 1. Infusion-related reactions (IRRs) were the most common SL-172154-related treatment-emergent AEs (TEAEs) reported in 13 (68%) and 8 (44%) pts in SL-mono and SL-AZA cohorts, respectively. IRRs (51 events) were Grade (G) 1 or 2 except for 3 G3 events (1 each at 6 mg/kg SL-mono and SL-AZA; 1 at 3 mg/kg SL-mono). Other SL-172154-related TEAEs observed in ≥ 3 pts were AST increased (4; 21%), ALT increased (3; 16%) and nausea (3; 17%) in SL-mono cohorts, and nausea (3; 17%) in SL-AZA cohorts. All events of AST/ALT increased were transient. Only one DLT (G3 IRR in the 6 mg/kg SL-AZA cohort) was reported, which required a dose reduction to 3 mg/kg. As of July 10, 2023, in SL-mono cohorts, 1 pt with R/R AML post 7+3, FLAG and VEN/AZA achieved Morphologic Leukemia-Free State (blast reduction from 19% to &amp;lt;5%) after 1 cycle of 6 mg/kg SL-172154 and proceeded to allogeneic hematopoietic cell transplant (allo-HCT) after cycle 2. In 12 evaluable pts with R/R AML receiving SL-AZA, although no objective responses (OR) were observed, relative reduction in bone marrow (BM) blasts from baseline was reported in 2/5 pts at 1 mg SL-AZA (-50%, -75%) and 5/7 pts at 3 mg SL-AZA (ranging from -35% to -90%). One pt underwent an allo-HCT. In 4 evaluable pts with UnTx TP53m-MDS, the ORs were 1 complete remission (CR), 1 marrow CR, and 2 stable disease. 2 of them proceeded to allo-HCT. SL-172154 induced elevations in serum IL-12p40, IP-10, IL-8, IL-10, MIP3α and MCP1: greater response at 3 mg/kg compared to 1 mg/kg while similar between 3 and 6 mg/kg. In the BM, SL-172154 induced a dose-dependent increase in phagocytic cells (CD11b, HLA-DR, CD16, CD36 and CD64) within mature myeloid immune cell compartments (CD45highCD34-). Reduction in leukemic blasts (CD45lowCD34+) was associated with an increase in mature myeloid and phagocytic cell phenotypes (3 mg/kg SL-AZA &amp;gt; 1 mg/kg SL-AZA). Conclusions: SL-172154 was well tolerated up to 3 mg/kg as monotherapy and in combination with AZA. Preliminary efficacy signals were detected in UnTx TP53m-MDS and R/R AML. A response to SL-172154 monotherapy, dose-dependent increases in serum cytokines and accumulation of mature myeloid cells in BM suggest a potential role for CD40 stimulation. Based on the safety, preliminary efficacy and pharmacodynamic activity, 3 mg/kg SL-172154+ AZA is being evaluated in treatment naïve pts with TP53m AML and HR-MDS.

Venetoclax Plus Azacitadine for Middle Aged and Elderly Patients with Newly Diagnosed Acute Myeloid Leukemia: Interim Analysis of a Prospective, Multicenter, Single-Arm, Phase 2 Trial

Background: “7+3” induction is the standard regimen in newly diagnosed young patients (pts) with acute myeloid leukemia (AML) fit for intensive chemotherapy with 60-80% complete remission rate. However, middle aged and elderly pts may experience more severe complications during induction therapy and overall survival is shorter than that of younger pts. Recently, venetoclax with azacitadine as induction therapy was approved as the first line therapy for pts with aged more than 75 years or unfit pts with composite complete remission (CRc) of 60-70%. We hypothesize that venetoclax with azacitadine as induction therapy in fit middle aged and elderly pts may have similar CRc rate and less complications. This study aims to evaluate the safety and efficacy of venetoclax plus azacitadine as induction therapy in fit middle aged and elderly newly diagnosed AML pts. Methods: This is an interim analysis of an ongoing phase 2 clinical trial (NCT05471700) of a planned 40 untreated AML pts aged 45-65 who were fit for intensive chemotherapy according to Ferrara Criteria. In cycle 1, pts received azacitadine 75mg/m2/day on d1-7 and venetoclax escalated from 100mg to 200mg to 400mg until 28-day cycle was finished. For pts with FLT3-ITD positive, sorafenib was optional administered at a dose of 400mg twice daily. Bone marrow assessments were performed on d28. Pts who achieved CRc (defined as complete remission[CR] and CR with incomplete hematologic recovery[CRi]) with intermediate or adverse risk groups received 1 or 2 cycles of consolidation with venetoclax plus azacitadine or center-specific cytarabine-based consolidation. Allogeneic stem cell transplantation (HSCT) was performed if a donor was available. Pts in favorable risk gruop received 3 to 4 cycles of center-specific intermediate or high dose cytarabine-base consolidation. Non-responders or pts who achieved partial remission received 1 more cycle of venetoclax plus azacitadine. Who could not get CRc after 2 cycles of induction would be withdrawn from the study. The primary objective is to determine the CRc rate. The secondary objective is safety, MRD negative rate, duration of remission (DOR), the rate of allo-HSCT, event free survival (EFS), and overall survival (OS). The endpoint is to show that venetoclax plus azacitadine is not inferior to “3+7” induction in fit pts with newly diagnosed AML aged 45-65. Results: From 10/9/2022 to 6/30/2023, a total of 32 pts was enrolled to this study, comprising 18 males and 14 females. There were 27 (84%) pts with de novo AML, 2(6%) pts were secondary AML, 3 pts (9.4%) were therapy-related AML. Median age was 58 years (range, 45-64 years). There were 2(6%), 14(44%) and 16(50%) pts were in the favorable, intermediate and adverse risk group, respectively. The baseline patient characteristics are summarized in Table 1. Outcome data were updated as of June 30, 2023, for a median follow-up of 2.2(0.2-8.8) months. Among 27 evaluable pts, 21(77.8%) achieved CRc with 11(40.8%) in CR and 10(37.0%) in CRi, 2(7.4%) achieved PR in cycle1, while 23(85.2%) achieved CRc with 14(51.9%) in CR and 9(33.3%) in CRi, 4(14.8%) got induction failure after 2 cycles(Figure 1). A total of 16 (61.5%) pts got MRD negative among the pts with CRc after cycle1, and 17 (65.4%) after cycle2. CRc rate after 2 cycles in ELN2017 favorable, intermediate, adverse risk group was 100%, 83.3% and 85.0%, respectively, and MRD negative rate was 100%, 88.9% and 55.6%, respectively. The regimen was well tolerated. No mortality occurred during induction therapy. The most common non-hematological grade 3/4 AE were febrile neutropenia (n=13, 40.6%)，followed by pneumonia (n=3, 9.4%).Sepsis occurred in 1 (3.1%) pt. With a median follow-up of 2.2(0.2-8.8) months, the median remission duration, EFS and OS have not been reached. Conclusions: Preliminary results indicate that venetoclax plus azacitadine as an induction regimen for fit middle aged and elderly pts with newly diagnosed AML is promising with high CRc and low toxicity. Recruitment of adults with newly diagnosed aged 45-65 AML pts for this trial is ongoing.

Correlation between Number of Molecular Mutations and Outcomes in De Novo Acute Myeloid Leukemia

Introduction Genomic sequencing of cancer has led to a deeper genetic understanding of the pathogenesis of acute myeloid leukemia (AML). Studies in myelodysplastic syndrome have shown that as the number of oncogenic mutations increases, patient outcomes progressively worsen. We hypothesized that patients with AML may also have a worse prognosis if they have a higher number of somatic mutations. To test this hypothesis, we examined the somatic mutational profile of 225 patients with previously untreated AML. Methods A single-center retrospective analysis was done utilizing the Kentucky Cancer Registry (KCR) and evaluated patients with de novo AML diagnosed between January 2015 to January 2021. Patient characteristics, cytogenetics, and molecular data were collected by chart review. Patients with available cytogenetic and somatic mutations profile from next-generation sequencing (NGS) were included. Clinically significant (CS) mutations for AML were detected by NGS performed on the diagnostic bone marrow specimen. The list of clinically significant mutations was obtained from My Cancer Genome and was compared to the mutations present in our patients. Statistical analysis was done using the Mann-Whitney U test for continuous variables and proportions were compared using Chi-square test. Overall survival (OS) was calculated by the Kaplan-Meier method and compared using a log-rank test. P value was considered significant if &amp;lt; 0.05. Results A total of 225 De Novo AML patients met inclusion criteria. The median age at diagnosis was 61 (range, 21-86). The population was fairly distributed among males (52%) and females (48%). Approximately 51% (n=115) of patients had 0-2 CS mutations, 43% (n=97) had 3-5 mutations, and 6 % (n=13) had &amp;gt; 5 CS mutations. The median number of CS mutations for the entire cohort was 2 (range: 0-9). Survival was worse in the group with &amp;gt;5 mutations when compared to those with 5 or less mutations (23 vs 7 months, p= 0.012, Figure 1). When analyzing the number of CS mutations per cytogenetic group, those with intermediate risk cytogenetics had a higher median number of CS mutations compared to the favorable and adverse risk group combined (3 versus 1, p &amp;lt; 0.001). In patients with &amp;gt; 5 CS mutations, 11/13 had a mutation associated with an adverse prognosis. To determine whether overall survival was impacted by the presence of an adverse mutation, a subgroup analysis was done using 43 patients with a normal karyotype and at least 1 adverse mutation. The cohort with &amp;gt; 5 CS mutations had a significantly shorter OS compared to patients with ≤ 5 CS mutations (43 vs 9 months, p= 0.001, Figure 2). Conclusion In summary, we found that patients with intermediate-risk cytogenetics have a high number of CS mutations. When patients were stratified by number of mutations, we found that a higher number of mutations (&amp;gt;5) led to statistically significant difference in survival compared to those with ≤5 mutations. To determine whether this difference in survival was a result of the presence of adverse risk mutations vs. number of mutations alone, we analyzed our patients who had normal karyotype with at least one adverse genetic mutation and stratified them based on number of mutations. The presence of more than 5 CS mutations was associated with a worse OS compared to ≤ 5 mutations. It appears that the number of clinically significant mutations may be an independent predictor of overall survival in AML. This can serve as another tool in stratifying AML risk with normal karyotype. This finding will need to be validated in a large prospective clinical trial.

A Randomized Phase 2 Trial of 28-Day (Arm A) Versus 14-Day (Arm B) Schedule of Venetoclax + Azacitidine in Newly Diagnosed Acute Myeloid Leukemia Patients ≥ 60 Years

Background: Treatment options for older, less fit acute myeloid leukemia (AML) patients continue to be challenging, with toxicities and limited efficacy. The combination therapy of azacitidine (Aza) and the bcl-2 inhibitor venetoclax (Ven) showed superior benefit in response rates and overall survival compared to Aza alone, leading to the combination's FDA approval in newly diagnosed AML patients ≥ 75 years and younger patients ineligible for intensive chemotherapy. While Ven-Aza is a very effective and potent therapy, the 28-day continuous dosing of Ven combined with 7 days of Aza resulted in interrupted dosing or shortened dosing schedules due to persistent cytopenias in more than 50% of treated patients in the VIALE-A trial and subsequent real-world data. Furthermore, investigation of novel agents in combination with Ven-Aza has been challenging due to prolonged cytopenias even when monotherapy with the new agent shows no myelosuppression. Given that Ven-Aza is not curative, successful integration of other agents with this standard of care remains important in AML. The growing knowledge of Ven-Aza toxicities prompted attention to developing a safer dosing regimen while maintaining similar efficacy. Our study will examine the FDA label of 28 days of Ven, versus 14 days, in combination with Aza for newly diagnosed AML patients ≥ 60 years who are not candidates for intensive chemotherapy. The primary objective of this study is to compare complete remission (CR) rates with an abbreviated schedule of Ven (14 days) versus the current package insert approved schedule (28 days). We hypothesize that reducing the dosing duration of Ven would reduce the associated toxicities while maintaining a comparable response rate. Study Design and Methods: This protocol is a sub-study of the Beat AML Master Trial (NCT03013998) in which untreated AML patients age ≥ 60 are assigned an investigational therapy based on cytogenetic and central genomic analysis. Patients are randomized onto Arm A (28-day Ven-Aza schedule) or Arm B (14-day Ven-Aza schedule) stratified by age (60-74 vs. 75+ years). The primary objective is to determine the complete remission (CR) rate of patients treated in each randomized arm for up to 2 cycles. The secondary objectives will include assessments of composite complete remission (CR, CR with hematologic improvement, CR with incomplete count recovery), duration of remission, survival, and incidence of treatment-related and non-related toxicities. Additionally, the overall incidence of febrile neutropenia, grade ≥3 infections, transfusions, days of hospitalization and time to neutrophil recovery will be determined. In both arms of the study, patients will be assessed for response at day 21-28 of cycles 1 and 2. Patients who have marrow remission (&amp;lt; 5% blasts) will wait for count recovery of absolute neutrophil count ≥ 0.5x10 9/L and platelets ≥ 50x10 9/L before initiating the next cycle of therapy. Patients will then be followed for survival. With the exception of the Ven dosing schedule (14 vs. 28 days), the FDA approved package insert for Ven, including dose modifications for concurrent azole therapy, will be followed in both arms. The intent of the analysis is to demonstrate that the 14-day Ven-Aza regimen is at least as effective as the standard 28-day regimen. A total of 166 patients (83 per group) will provide 80% power to detect a 10% non-inferiority margin at the one-sided 5% significance level, assuming that the CR rate is 36% for the 28-day regimen, as observed in VIALE-A, and 25% higher (45%) for the 14-day regimen. In addition to assessing the frequency of adverse events such as cytopenias, safety monitoring will include an assessment of response rates after at least 25% of patients have completed 2 cycles of treatment, with consideration for stopping the study if data suggest the 14-day regimen is inferior to the standard regimen. Correlative studies will include measurement of MRD and a focus on identifying properties of leukemic cells that respond, do not respond and become resistant to therapy.

Acute Myeloid Leukemia Driven IL-3 Dependent Upregulation of BCL-2 in Non-Malignant Hematopoietic Progenitor Cells Increases Venetoclax Induced Cytopenias

The BH3 mimetic venetoclax, in combination with low dose cytarabine, decitabine or azacitidine has shown clinical efficacy in newly diagnosed acute myeloid leukemia (AML) (1, 2). This has been a significant advance, particularly in the treatment of older AML patients, and those who are ineligible for intensive chemotherapy, who historically have been difficult to treat. Venetoclax selectively inhibits the BCL-2 protein which is overexpressed in AML in order to activate intrinsic apoptosis. However, this treatment regime is associated with cytopenias including neutropenia, febrile neutropenia, and thrombocytopenia which leaves patients immunocompromised (3). The underlying cause of cytopenias in the context of venetoclax-treated AML remains unexplained. Here we describe a mechanism for venetoclax-induced cytopenias in AML. Two established AML models were used to assess BCL-2 expression profile in HPCs. Isolated LSK cells were co-cultured with mouse AML (HOXA9/Meis1 or MN1 overexpressing cells). RT-qPCR analysis identified BCL-2 upregulation in LSKs co-cultured with both AML cell types. To understand the significance of this in vivo, MN1 cells were engrafted into C57BL/6 mice and LSKs were FACS purified. Analysis confirmed increased BCL-2 gene and protein expression by RT-qPCR and flow cytometry when compared to control LSKs. Next, to recapitulate the clinical cytopenias, MN1 engrafted mice or control mice were treated with venetoclax for 7 days by oral gavage. Flow cytometry analysis of bloods and bone marrow in venetoclax-treated AML mice determined neutrophil depletion and reduced numbers of HPCs, namely LSK, MPP, HSC and GMP, compared to untreated AML mice . Todetermine the mechanism of BCL-2 upregulation in LSKs we explored various signalling pathways using targeted inhibitors on LSKs cultured with MN1 conditioned media. Using this method, we established that interleukin 3 (IL-3) activates BCL-2 transcription in LSKs leading to a dependency on pro-survival BCL-2 protein. Furthermore, treatment of LSKs, cultured in MN1 conditioned media with IL-3 neutralising antibody MP2-8F8 reduced BCL-2 gene and protein expression in LSKs. Finally, MN1 engrafted mice were treated with venetoclax and IL-3 neutralising antibody in combination which restored neutrophil levels to numbers observed in untreated AML mice. Here, we demonstrate that BCL-2 is overexpressed in non-malignant HPCs during AML progression using two AML models. In addition, using our syngeneic mouse model we show that venetoclax induces HPC depletion. In vitro studies confirm that IL-3 mediates BCL-2 upregulation in HPCs - this sensitises HPCs to venetoclax and causes cytopenias. We also demonstrate that neutrophils can be recovered using IL-3 neutralisation in combination with venetoclax in AML engrafted mice. Taken together, these findings provide biologic insight for IL-3 inhibition alongside venetoclax to reduce the incidence of cytopenias observed in elderly AML patients.

Serum Amyloid A1 (SAA1) Secreted By the Stromal Microenvironment Drives Malignant Clonal Proliferation in Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML)

Drivers of malignant hematopoietic stem cell clonal proliferation from age-related clonal hematopoiesis (ARCH) to Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) are not well understood. However, a pro-inflammatory and immune tolerant aging bone marrow (BM) microenvironment is thought to contribute to disease development. Serum Amyloid A1 (SAA1) has been identified as a novel pro-inflammatory oncoprotein the levels of which progressively increase with MDS and AML progression. SAA1 also selectively promotes growth of patient-derived MDS and AML cells independent of cytogenetic or mutational profile. We aimed to characterize the mechanism by which SAA1 drives oncogenesis within the microenvironment. Herein we further stratified the disease marking properties of SAA1 by clarifying the association of its BM levels with disease progression in MDS and AML. SAA1 levels were significantly elevated in BM aspirates from MDS and AML patients as compared to those from healthy age-matched subjects (p=0.0002 and p=0.0052, respectively). The effects of SAA1 on mutated hematopoietic cells were assessed in a model of age-related clonal hematopoiesis (ARCH). Utilizing a CRISPR-Cas9 system, ASXL1-mutant CD34+ hematopoietic stem cells (HSCs) were generated; the replating capacity of both mutated and healthy CD34+ cells were assessed in the presence or absence of SAA1. Notably, SAA1 increased the replating capability assessed by an increase in the number of colonies formed on serial replating of ASXL1-mutant CD34+ cells, but not those of SAA1-treated healthy CD34+ or vehicle treated ASXL1-mutated CD34+ cells, suggesting that the presence of SAA1 favors stemness of mutated HSCs, and implicating SAA1 as a driver of malignant clonality. To investigate the mechanism of action of SAA1 BM mononuclear cells from AML patients or healthy age-matched subjects were treated with SAA1 or vehicle overnight and single-cell RNA sequencing analysis was performed. Seurat and cell cluster annotation analysis showed that AML samples treated with SAA1 had increased numbers of hematopoietic stem and progenitor cells (HSPCs) and plasmacytoid dendritic cells as compared to matched untreated AML samples. Further, Enrichr analysis showed that pathways upregulated by SAA1 in AML samples included pro-inflammatory molecules, anti-apoptotic, and antiviral defense mechanisms (p&amp;lt;0.0001). Shared genes upregulated in these pathways in HSPCs include interferon-induced signals including JAK2, STAT1, and OAS3, and genes implicated in resistance to chemotherapy, including CD44 and CD36, as well as the anti-phagocytosis signal CD47. Lastly, we initiated the development of a blocking monoclonal antibody against SAA1 as a means of inhibiting its potent oncogenic effects on malignant HSCs and examining its potential therapeutic activity. Utilizing a RAW 264.7 NFκB-luciferase reporter cell line, we screened 51 clones for their ability to selectively block SAA1-mediated NFκB activation. 7 optimal candidates were identified which demonstrated dose-dependent reduction in NFκB activity upon SAA1 challenge. Importantly, these candidate clones were specific for SAA1 and did not affect NFκB activation mediated by lipopolysaccharide (LPS)-mediated activation. We observed up to an 85% reduction of SAA1-mediated activity using supernatants from further subcloning of previously selected candidates. Moreover, cell proliferation of a human AML cell line (OCI-AML3) stimulated by SAA1 was markedly reduced in the presence of candidate antibodies, suggesting anti-proliferative activity. Our findings show that SAA1 levels correlates with disease severity in MDS and AML progression, selectively promotes stemness and proliferative potential of ASXL1-mutant cells, and demonstrates unique immune-related mechanisms selecting for malignant clonality. Further development and purification of a novel inhibitory antibody against SAA1 for future in vivo and ex vivo testing is underway as a promising novel target to reduce SAA1-mediated, niche-driven effects with broad implications in the treatment of hematological malignancies.

Type 3 Innate Lymphoid Cells Promote Acute Myeloid Leukemia Immune Evasion and Expansion

Acute Myeloid Leukemia (AML) is an aggressive myeloid malignancy originated in the bone marrow with poor overall survival rates of less than 30%. The immune system has been shown to play an important role in detecting and eliminating leukemic cells. Recent studies have described a population of immune cells termed Innate lymphoid cells (ILCs). ILCs are known to regulate both innate and adaptive immunity in an antigen-independent manner and are believed to be among the first immune cells to interact with malignantly transformed cells. Natural killer (NK) cells are a subset of ILCs and are known to inhibit AML progression, however the impact of other ILCs is not yet fully understood. Type 3 ILCs (ILC3s) have key roles in maintaining homeostasis in mucosal immunity through their ability to secrete cytokines including IL-17, IL-22, TNFα and GM-CSF (pro-myeloid). An expansion of ILC3s has recently been observed in solid tumors, however the overall functional impact of ILC3s in the setting of AML remains poorly understood and warrants further investigation. We first utilized an MLL-partial tandem duplication and FLT3-internal tandem duplication Flt3-ITD double knock-in mutation murine model of AML that recapitulates two clinically relevant mutations in human AML. Using this AML model, we discovered an expansion of ILC3s in the bone marrow of leukemic mice compared to wild-type control mice (2.364% +/- 0.40% AML vs 0.045% +/- 0.40% WT, n=5, p&amp;lt;0.0001). We also observed an increase in ILC3s in the bone marrow of untreated AML patients relative to age matched donor controls (7.013% +/- 2.6% vs. 2.328% +/- 2.6%). Our published data have previously shown AML blasts secrete aryl hydrocarbon receptor (AHR) ligands, which can bind and activate the transcription factor AHR in ILC precursors and mature ILCs. AHR is an important transcription factor in ILC3 development. Therefore, we hypothesized that the ILC3 increase was due at least in part to AHR-mediated increased ILC3 differentiation. To address this hypothesis, we isolated the ILC precursor (ILCP) from normal human donors and co-cultured with AML cells. By regulating AHR activity in this system, we showed that ILC3s are expanded in AML in part due to AML-mediated AHR activation (28.02% +/- 3.89% without AML, 60% +/- 5.5% with AML and 27% +/- 5% AML+AHR inhibitor, n=15, p&amp;lt;0.001). Next, we sought to determine the direct impact of ILC3s on AML proliferation and differentiation that could contribute to AML relapse. We utilized a colony forming assay (CFU) assay in the presence or absence of ILC3s. Bone marrow from primary untreated AML patients was cultured alone or with ILC3s (Lin-CD94-NKp44+). AML samples co-cultured with ILC3s had significantly increased colony formation relative to AML alone (69.4 CFU AML+ILC3 vs 42.7 CFU AML alone, n=8, p&amp;lt;0.05). Post-culture, we observed significant increases in the transcript of GM-CSF and TNFα in ILC3s co-cultured with AML marrow as compared to ILC3s alone. Furthermore, in our immunocompetent murine AML model, we observed significantly higher production of GM-CSF and TNFα by ILC3s in the bone marrow of leukemic mice relative to nonleukemic controls (GM-CSF: 11.08% +/- 1.6 AML vs 1.128% +/- 1.6 WT, n=10, p&amp;lt;0.0001; TNFα: 5.456% +/- 1.3 AML vs 1.307% +/- 1.3 WT, n=10, p&amp;lt;0.05), suggesting a potential mechanism of ILC3-mediated increased colony formation. Lastly, to determine if ILC3 expansion impacted NK cell immune surveillance, we co-cultured normal donor human ILC3s with AML cells, separated by transwell, for 48 hours before subjecting the AML cells to an NK cell cytotoxicity assay. We observed significantly reduced NK cell killing of AML cells when co-cultured with ILC3s compared to controls, suggesting ILC3s protect AML cells from NK cell-mediated killing (24.3% killing +/- 3.81% AML alone vs 14.57% +/- 1.35% AML with ILC3, n=18, p&amp;lt;0.01). Collectively, these data support a model in which AML-mediated AHR activation promotes ILC3 expansion to both support AML proliferation and protect AML blasts from immune surveillance. Future studies will focus in exploring how to target these interactions to design effective therapeutic approaches and improve patient clinical outcomes.

Trial in Progress: An Open Label Phase I/II, Multicenter Study Evaluating Safety, Pharmacokinetics and Efficacy of S65487, a BCL-2 Inhibitor Combined with Azacitidine in Adults with Previously Untreated Acute Myeloid Leukemia Ineligible for Intensive Treatment

Preclinical and clinical data support combining Bcl-2 inhibitors (Bcl-2i) with hypomethylating agents (HMAs) in the treatment of acute myeloid leukemia (AML). S65487, a potent intravenous Bcl-2i, has shown promising synergistic activity when combined with azacitidine against in vitro AML models. Based on those data, we initiated a Phase I/II multicenter study of S65487 combined with azacitidine for newly diagnosed patients aged 18 years or older with de novo or secondary AML ineligible for intensive chemotherapy in 6 countries in Europe and Asia (NCT04742101). Secondary AML was defined as those related to previous leukemogenic therapies or transformed from a myelodysplastic syndrome. Patients with AML originating from myeloproliferative disorders were excluded. Ineligibility to intensive chemotherapy was defined as age of at least 75 years or the presence of significant co-morbidities. Previous use of HMA was allowed in the first six dose levels tested in the Phase I portion of the study, but was excluded afterwards, including during the Phase II part. Other eligibility criteria were standard for this patient population. Each cycle of therapy lasts for 28 days. Subcutaneous or intravenous azacitidine is administered at a dose of 75mg/m 2 in 7 consecutive administrations per cycle starting on day (D) 1 with a 2-day interval during weekends. Three schedules of S65487 are planned to be tested during the Phase I part to increase its concurrent administration with azacitidine and their synergism. Schedule 1 consists of weekly administrations (doses on D1, 8, 15, and 22). Two more intensified schedules consist of S65487 administration on D1, D3, D5, D8 (schedule 2) or D1 through D5, D8, and D9 (schedule 3) on the same days of azacitidine dosing. S65487 is administered over 30 minutes. When administered on the same day, S65487 is given first followed by azacitidine within 30 to 60 minutes. Treatment should be discontinued due to disease progression, or if other standard withdrawal criteria are met. The Phase I portion of the study follows a standard design guided by an adaptive Bayesian Logistic Regression Model with overdose control to estimate the maximum tolerated dose (MTD) based on the occurrence of dose-limiting toxicities during cycle 1. Patient accrual for the Phase I portion of this study is ongoing. The planned testing of schedule 1 is limited due to the expected low synergism with azacitidine. Once the recommended Phase II dose (RP2D) or MTD are established for schedules 2 and 3, the Phase II part will start and will be comprised of a maximum of two cohorts, each containing up to 27 patients. A Bayesian optimal design based on complete remission rate will guide the Phase II. Interim futility analyses are planned after enrollment of 10 and 20 evaluable patients. Randomization will not be used to allocate patients to one of the two cohorts planned during the Phase II portion of the study. The primary objective during the Phase I is to determine the safety, tolerability, and the RP2D or MTD of S65487 in combination with azacitidine. The primary objective of the Phase II is to assess the efficacy of this therapy. Pharmacokinetic analyses are included as secondary objectives in both parts of the study. Measurable residual disease will be assessed as a secondary objective in the Phase II part using a well validated, standard flow-cytometry panel. Pharmacodynamic analyses are conducted as exploratory objectives in both parts of the study. In particular, the disruption of the BCL2/BIM complex is followed in peripheral-blood mononuclear cells to guide the estimation of the RP2D.

Tumor Lysis Syndrome in Patients with AML Initiated on Venetoclax-Based Treatment without a Dose Ramp-up

Introduction Treatment with the combination of a hypomethylating agent (HMA) and venetoclax (VEN) is the standard of care for older patients (pts) with acute myeloid leukemia (AML). Venetoclax, an oral BCL-2 inhibitor, was initially approved for the treatment of chronic lymphocytic leukemia (CLL). In the early, pivotal studies assessing VEN safety, tumor lysis syndrome (TLS) was found to be a dose-limiting, potentially fatal toxicity. Dosing modifications were made to allow for safer initiation of the drug and, ultimately, a dose ramp-up was included in the dosing recommendation for CLL. Given the risk for TLS with VEN initiation for CLL, it was hypothesized that the risk would be the same, or potentially greater, when treating pts with AML. Therefore, studies of VEN in AML have included a dose ramp-up. Although reported rates of tumor lysis syndrome in these studies have been much lower than expected, a dose ramp-up for pts with AML is included in the package insert for VEN and continues to be utilized in clinical trials. Methods We conducted a retrospective analysis of pts ≥18 years of age with newly diagnosed or relapsed/refractory AML treated with a standard dose hypomethylating agent (HMA), either azacitidine or decitabine, and VEN without a dose ramp-up (initiated at 400mg daily or 100mg daily if on concomitant voriconazole or posaconazole) at Thomas Jefferson University Hospital from January 1, 2018- August 1, 2021. The primary objective of this study was to determine the rate of laboratory and clinical TLS within 72 hours after chemotherapy initiation, as defined by the Cairo-Bishop criteria (Table 1). The secondary objectives were (1) to identify clinical and laboratory risk factors for the development of TLS in pts with AML who were treated with HMA-VEN without a VEN dose ramp-up and (2) to compare rates of TLS in pts with AML who were treated with HMA-VEN without a VEN dose ramp-up to historical rates of TLS in pts who underwent a VEN dose ramp-up. In the Phase 3 study of azacitidine and venetoclax the rate of TLS during the VEN dose ramp-up period (days 1-3 of treatment) was 1% (DiNardo CD, Jonas BA, Pullarkat V, et al. Azacitidine and venetoclax in previously untreated acute myeloid leukemia. N Engl J Med. 2020;383(7):617-629.). Results Ninety pts were included in the analysis. Seventy-one pts had newly diagnosed AML and 19 had relapsed/refractory disease. The majority of pts (58/90, 64%) had adverse risk disease by 2017 European LeukemiaNet Criteria. Median baseline white blood cell count at the time of therapy initiation was 3.25 (range 0.5-161.4). Sixty-one pts (68%) were receiving allopurinol prophylaxis at the time of HMA-VEN administration. Eighteen pts (20%) had a history of underlying renal disease. Fifteen pts (17%) were on medications, such as thiazide diuretics, aspirin, or levodopa, that can increase the risk of TLS at the time of treatment. Zero pts met the defined criteria for laboratory or clinical TLS. One pt developed acute kidney injury and one pt developed a cardiac arrhythmia (atrial fibrillation) but neither had concomitant evidence of laboratory TLS. Discussion In this retrospective study of 90 pts with newly diagnosed or relapsed/refractory AML who were treated with HMA-VEN without a VEN dose ramp-up no pts developed clinical or laboratory tumor lysis syndrome. This is comparable to the rate of TLS (1%) seen in the registration trial of HMA-VEN where pts were treated with VEN 100 mg on day 1, 200 mg on day 2, and 400 mg on day 3 and thereafter. Starting pts with AML on full dose VEN on day 1, regardless of white blood cell count, renal function, or concomitant medications, appears safe and could be implemented in clinical practice and clinical trials moving forward. This would simplify dosing for pts, pharmacists, and providers and allow for easier initiation of therapy.

Ibrutinib Combined with Venetoclax in Patients with Relapsed/Refractory Mantle Cell Lymphoma: Primary Analysis Results from the Randomized Phase 3 Sympatico Study

Background: Ibrutinib (Ibr) is a once-daily Bruton tyrosine kinase (BTK) inhibitor approved in multiple regions for patients (pts) with mantle cell lymphoma (MCL) who have received ≥1 prior therapy. Venetoclax (Ven) is a BCL-2 inhibitor approved in the US for pts with chronic lymphocytic leukemia and previously untreated acute myeloid leukemia. Ibr and Ven have distinct and complementary modes of action, and the combination has shown promising clinical activity in early phase studies in MCL (Tam, N Engl J Med 2018; Wang, J Hematol Oncol 2021). Here, we report the primary analysis results from the multinational, randomized, double-blind, phase 3 SYMPATICO (NCT03112174) study comparing Ibr+Ven vs Ibr + placebo (Pbo) in pts with relapsed/refractory (R/R) MCL. Methods: Pts aged ≥18 y with R/R MCL after 1-5 prior therapies were randomly assigned 1:1 to receive oral Ibr 560 mg once daily concurrently with oral Ven (standard 5-wk ramp-up to a target dose of 400 mg once daily) or Pbo for 2 y, followed by single-agent Ibr until progressive disease (PD) or unacceptable toxicity. Randomization was stratified based on ECOG PS, prior lines of therapy, and tumor lysis syndrome (TLS) risk based on tumor burden and CrCl. The primary endpoint was progression-free survival (PFS) by investigator (INV) assessment using Lugano criteria; pts without PD or death were censored at the last non-PD assessment (per global censoring rules). Additional sensitivity analyses included PFS assessment by independent review committee (IRC) and censoring per US FDA rules (Table). Key secondary endpoints were tested hierarchically in the following order: complete response (CR) rate by INV assessment, time to next treatment (TTNT), overall survival (OS, interim analysis), and overall response rate (ORR) by INV assessment. Results: A total of 267 pts were enrolled and randomly assigned to receive Ibr+Ven (n=134) or Ibr+Pbo (n=133). Median age was 68 y; 96% of pts had an ECOG PS of 0-1, 17% had ≥3 prior lines of therapy, and 22% were at increased risk for TLS. At baseline, pts in the Ibr+Ven vs Ibr+Pbo arms had median ages 69 vs 67 y, high-risk simplified MCL International Prognostic Index score 38% vs 31%, bulky disease ≥5 cm 46% vs 40%, bone marrow involvement 46% vs 41%, splenomegaly 31% vs 25%, and TP53 mutated 30% vs 28%; other baseline characteristics were generally similar between arms. With a median time on study of 51.2 mo, median PFS by INV assessment was significantly longer with Ibr+Ven vs Ibr+Pbo (31.9 vs 22.1 mo), with a hazard ratio (HR) of 0.65 (95% CI, 0.47-0.88; stratified log-rank P=0.0052) (Figure). PFS rates at 24 mo were 57% and 45% with Ibr+Ven and Ibr+Pbo, respectively. PFS benefit with Ibr+Ven vs Ibr+Pbo was generally consistent across prespecified subgroups, including those with blastoid variant or TP53-mutated MCL. Sensitivity analyses of PFS were consistent with the primary analysis (Table). Ibr+Ven significantly improved CR rates (54% vs 32%) and TTNT (median not reached [NR] vs 35.4 mo); at the current 51.2 mo median follow-up, median OS was 44.9 mo with Ibr+Ven vs 38.6 mo with Ibr+Pbo (HR 0.85 [95% CI, 0.62-1.19]) (Table). Median duration of treatment was 22.2 mo for the Ibr+Ven arm and 17.7 mo for the Ibr+Pbo arm; at the time of analysis, 30% of pts in the Ibr+Ven arm and 20% of pts in the Ibr+Pbo arm remained on single-agent Ibr. Grade ≥3 adverse events (AEs) occurred in 84% of pts with Ibr+Ven vs 76% with Ibr+Pbo; the most frequent (occurring in ≥5% of pts) were neutropenia (31% vs 11%), pneumonia (13% vs 11%), thrombocytopenia (13% vs 8%), anemia (10% vs 3%), diarrhea (8% vs 2%), leukopenia (7% vs 0%), MCL (7% vs 12%), atrial fibrillation (5% vs 5%), COVID-19 (5% vs 1%), and hypertension (4% vs 9%). Serious AEs occurred in 60% of pts in each arm. No clinical TLS occurred; laboratory TLS occurred in 5% and 2% of pts in the Ibr+Ven and Ibr+Pbo arms, respectively. COVID-19 deaths occurred in 10 pts in each arm and had no meaningful impact on PFS or OS HRs. Conclusion: The Ibr+Ven combination demonstrated a statistically significant improvement in PFS compared with Ibr+Pbo in pts with R/R MCL; CR rates and TTNT were also significantly improved with Ibr+Ven. OS was numerically but not significantly improved at this interim analysis. The safety profile of Ibr+Ven was consistent with known AEs for each agent, with no new safety signals observed. Overall, these results demonstrate a favorable benefit-risk profile for Ibr+Ven in pts with R/R MCL.

Cusatuzumab plus azacitidine in newly diagnosed acute myeloid leukaemia ineligible for intensive chemotherapy (CULMINATE): part one of a randomised, phase 2, dose optimisation study

Cusatuzumab, a high-affinity anti-CD70 antibody, has shown preliminary activity as a treatment for acute myeloid leukaemia when combined with azacitidine. We aimed to determine the optimum dose for future trials of cusatuzumab in combination with azacitidine in patients with previously untreated acute myeloid leukaemia who are not eligible for intensive chemotherapy. In this randomised, phase 2, open-label, dose-optimisation study we enrolled adult patients aged 18 years or older with newly diagnosed acute myeloid leukaemia not eligible for intensive chemotherapy, and with Eastern Cooperative Oncology Group scores of 0-2, from 40 hospitals and centres across seven countries. In part one of the trial, participants were randomly allocated 1:1 to 10 mg/kg or 20 mg/kg intravenous cusatuzumab on days 3 and 17, combined with subcutaneous or intravenous azacitidine 75 mg/m2 on days 1-7 in 28-day cycles. The primary efficacy outcome was the rate of complete remission in the intention-to-treat group. The two dose cohorts were evaluated independently without between-cohort statistical comparison. Safety analyses were performed in all patients who received one dose of study drug. Part two of the trial was planned to be a single-arm expansion to evaluate cusatuzumab plus azacitidine at the cusatuzumab dose level selected in part one (primary hypothesis ≥35% rate of complete remission vs null hypothesis of 20%); however, changes in the acute myeloid leukaemia treatment landscape during this trial made it unlikely that enrolment to part two of the study would be clinically feasible, so the study stopped at the end of part one. The trial was registered at ClinicalTrials.gov, NCT04023526. 103 patients were enrolled between Aug 30, 2019, and Feb 25, 2020, and randomly assigned to either cusatuzumab 10 mg/kg (n=51) or 20 mg/kg (n=52). Median follow-up was 7·2 months (IQR 10·7 months). 57 of 103 (55%) patients were male and 46 (45%) patients were female, 78 (76%) were White, one (1%) was Asian, and 24 (23%) did not report their race. In the 10 mg/kg group, complete remission rate was 12% (six of 51 patients; 95% CI 6-23) and in the 20 mg/kg group was 27% (14 of 52; 17-40). Grade 3 or worse treatment-emergent adverse events (TEAEs) were similar between the cusatuzumab 10 mg/kg (n=51) and 20 mg/kg (n=51) cohorts and included thrombocytopenia (24 patients [47%] vs 29 [57%]), anaemia (24 [47%] vs 17 [33%]), and neutropenia (20 [39%] in both cohorts). Serious TEAEs were also similar in the two cohorts (44 [86%] vs 40 [78%]). Treatment-related TEAEs leading to death were reported in both groups (three patients [6%] in the 10 mg/kg group vs one patient [2%] in the 20 mg/kg group); the reported causes of death were pneumonia (n=2) and septic shock (n=2). Although part one of this study was not designed to formally compare the two dose cohorts for efficacy, the totality of clinical data for cusatuzumab studies performed to date indicate that cusatuzumab 20 mg/kg plus azacitidine represents the optimal dose for further studies. A phase 1b study investigating the triple combination of cusatuzumab with venetoclax and azacitidine is underway (NCT04150887). Janssen Research & Development and argenx.

Comparative Efficacy of Venetoclax-Based Combination Therapies and Other Therapies in Treatment-Naive Patients With Acute Myeloid Leukemia Ineligible for Intensive Chemotherapy: A Network Meta-Analysis

ObjectivesThis network meta-analysis (NMA) assessed the efficacy of venetoclax (VEN) + azacitidine (AZA) and VEN + low-dose cytarabine (LDAC) compared with AZA, LDAC, and decitabine monotherapies and best supportive care (BSC) in adults with untreated acute myeloid leukemia ineligible for intensive chemotherapy. MethodsA systematic literature review and feasibility assessment was conducted to select phase III randomized controlled trials for inclusion in the NMA. Complete remission + complete remission with incomplete blood count recovery and overall survival (OS) were compared using a Bayesian fixed-effects NMA. Treatments were ranked using surface under the cumulative ranking curves (SUCRAs) with higher values indicating a higher likelihood of being effective. ResultsA total of 1140 patients across 5 trials were included. VEN + LDAC (SUCRA 91.4%) and VEN + AZA (87.5%) were the highest ranked treatments for complete remission + complete remission with incomplete blood count recovery. VEN + LDAC was associated significantly higher response rates versus AZA (odds ratio 5.64), LDAC (6.39), and BSC (23.28). VEN + AZA was also associated significantly higher response rates than AZA (5.06), LDAC (5.74), and BSC (20.68). In terms of OS, VEN + AZA (SUCRA: 95.2%) and VEN + LDAC (75.9%) were the highest ranked treatments. VEN + AZA was associated with significant improvements in OS compared with AZA (hazard ratio 0.66), LDAC (0.57), and BSC (0.37), and VEN + LDAC was associated with significant improvements in OS compared with LDAC (0.70) and BSC (0.46). ConclusionsVEN + AZA and VEN + LDAC demonstrated improved efficacy compared with alternative therapies among treatment-naive patients with acute myeloid leukemia ineligible for intensive chemotherapy.

Phase 1/2 Study of Sorafenib Added to Cladribine, High-Dose Cytarabine, G-CSF, and Mitoxantrone in Untreated AML.

The multikinase inhibitor sorafenib improves event-free survival (EFS) when used with 7+3 in younger adults with newly diagnosed acute myeloid leukemia (AML) irrespective of FLT3 mutation status. Here, we evaluated adding sorafenib to CLAG-M (cladribine, high-dose cytarabine, G-CSF, mitoxantrone) in a phase 1/2 trial of 81 adults age ≤60 years with newly diagnosed AML or high-grade myeloid neoplasm. Forty-six patients were treated in phase 1 with escalating doses of sorafenib and mitoxantrone. No maximum tolerated dose was reached, and a regimen including mitoxantrone at 18 mg/m2/day and sorafenib 400 mg twice daily was declared the recommended phase 2 dose (RP2D). Among 41 patients treated at the RP2D, a measurable residual disease-negative complete remission (MRDneg CR) rate of 83% (95% confidence interval [CI]: 68-93%) was obtained. Four-week mortality was 2% (95% CI: 0-13%). One-year overall survival (OS) and EFS were 80% (95% CI: 69-94%) and 76% (95% CI 64-90%), without significant difference in MRDneg CR rates, OS, or EFS between patients with or without FLT3-mutated disease. Comparing outcomes with CLAG-M/sorafenib to a matched cohort of 76 patients treated with CLAG-M alone, multivariable adjusted survival estimates were improved for the 41 patients receiving CLAG-M/sorafenib at RP2D (OS: hazard ratio [HR]=0.24 [95% CI: 0.07-0.82], P=0.023; EFS: HR=0.16 [95% CI: 0.05-0.53], P=0.003). Statistically significant benefit was limited to patients with intermediate-risk disease (in univariate analysis, P=0.01 for OS and P=0.02 for EFS). These data suggest CLAG-M/sorafenib is safe and improves OS and EFS relative to CLAG-M alone, with benefit primarily for patients with intermediate-risk disease. The trial is registered on clinicialtrials.gov as NCT02728050.

Glasdegib plus intensive or non-intensive chemotherapy for untreated acute myeloid leukemia: results from the randomized, phase 3 BRIGHT AML 1019 trial

This is the primary report of the randomized, placebo-controlled phase 3 BRIGHT AML 1019 clinical trial of glasdegib in combination with intensive chemotherapy (cytarabine and daunorubicin) or non-intensive chemotherapy (azacitidine) in patients with untreated acute myeloid leukemia. Overall survival (primary endpoint) was similar between the glasdegib and placebo arms in the intensive (n = 404; hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.782–1.408; two-sided p = 0.749) and non-intensive (n = 325; HR 0.99; 95% CI: 0.768–1.289; two-sided p = 0.969) studies. The proportion of patients who experienced treatment-emergent adverse events was similar for glasdegib versus placebo (intensive: 99.0% vs. 98.5%; non-intensive: 99.4% vs. 98.8%). The most common treatment-emergent adverse events were nausea, febrile neutropenia, and anemia in the intensive study and anemia, constipation, and nausea in the non-intensive study. The addition of glasdegib to either cytarabine and daunorubicin or azacitidine did not significantly improve overall survival and the primary efficacy endpoint for the BRIGHT AML 1019 phase 3 trial was not met. Clinical trial registration: ClinicalTrials.gov: NCT03416179.

Social determinants of health as a primary driver in outcomes in acute myeloid leukemia: An urban academic center experience.

e18659 Background: Healthcare disparities are pervasive in the treatment of cancer. Black patients with acute myeloid leukemia (AML) have shorter survival and inferior outcomes compared to White patients. Lack of insurance coverage decreases survival further. However, outcomes with respect to individual chemotherapy regimens remain unclear. Methods: We analyzed 306 patients with untreated AML that received front-line induction with an anthracycline and cytarabine (7+3) at VCU Massey Cancer Center between January 1, 2013 and January 1, 2022 in this single-center, retrospective analysis. We stratified patients into two cohorts: those that had private insurance or Medicare and those that had no insurance or Medicaid. We recorded baseline demographics, performance status, disease characteristics, response, receipt of allogeneic stem cell transplant (alloSCT), and survival. Patients who were alive at the end of the study period or were lost to follow-up were censored at the date of last contact. Results: There were 243 patients with private insurance or Medicare (Pi/M) and 63 patients with no insurance or Medicaid (Ni/M). The median age was 60 years (range, 18-77) in the Pi/M cohort and 52 years (range, 22-71) in the Ni/M cohort ( p &lt; 0.001). Most patients with private insurance or Medicare tended to be White (72.7% for Pi/M versus 36.1% for Ni/M, p &lt; 0.0001). There were no differences in sex (p = 0.778), the median ECOG score (1 versus 1, p = 0.096), or the median CCI score (4 versus 3, p = 0.607). There were no differences in the distribution of ELN 2017 risk, secondary AML ( p = 0.619), or procession to alloSCT ( p = 0.145). There was no difference in the composite complete remission (CRc; CR + CRi) rate between the Pi/M [44.5% (95% CI, 38.5-51.0)] and Ni/M cohorts (52.6% [95% CI, 39.9-65.0], p = 0.301). The median overall survival significantly favored the patients with private insurance or Medicare (21.7 months versus 15.2 months; log-rank, p = 0.030). Conclusions: AML patients with Medicaid or without insurance tend to be younger minorities. Despite no difference in fitness, disease characteristics, or even response to first-line chemotherapy, the median overall survival significantly favors patients with private insurance or Medicare. Our data clearly illustrates the primary role of social determinants of health in overall outcomes. Policymakers and physicians should push for improved access to care and more affordable insurance coverage. [Table: see text]