Begna, Kebede H.

Chronic myeloid leukemia (CML) is defined by the presence of Philadelphia chromosome resulting from a reciprocal translocation between chromosomes 9 and 22 [t9;22] that gives rise to a BCR::ABL1 fusion gene. CML occurs in 3 different phases (chronic, accelerated, and blast phase) and is usually diagnosed in the chronic phase in developed countries. Tyrosine kinase inhibitor (TKI) therapy is a highly effective treatment option for patients with chronic phase–CML. The primary goal of TKI therapy in patients with chronic phase–CML is to prevent disease progression to accelerated phase–CML or blast phase–CML. Discontinuation of TKI therapy with careful monitoring is feasible in selected patients. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with chronic phase–CML.

SummaryAmong 301 newly diagnosed patients with acute myeloid leukaemia receiving venetoclax and a hypomethylating agent, 23 (7.6%) experienced major cardiac complications: 15 cardiomyopathy, 5 non‐ST elevation myocardial infarction and/or 7 pericarditis/effusions. Four patients had more than one cardiac complication. Baseline characteristics included median age ± interquartile range; 73 ± 5 years; 87% males; 96% with cardiovascular risk factors; and 90% with preserved baseline ejection fraction. In multivariate analysis, males were more likely (p = 0.02) and DNMT3A‐mutated cases less likely (p < 0.01) to be affected. Treatment‐emergent cardiac events were associated with a trend towards lower composite remission rates (43% vs. 62%; p = 0.09) and shorter survival (median 7.7 vs. 13.2 months; p < 0.01). These observations were retrospectively retrieved and warrant further prospective examination.

SummaryAmong 210 patients with myelodysplastic syndromes (MDSs) with del(5q), molecular information was available at diagnosis or at least 3 months before leukaemic transformation in 146 cases. Multivariate analysis identified therapy‐related setting (p = 0.02; HR 2.3) and TP53 variant allele frequency (VAF) ≥22% (p < 0.01; HR 2.8), but not SF3B1 mutation (p = 0.65), as independent risk factors for survival. Median survival was 11.7 versus 4 years (5/10‐year survival 73%/52% vs. 42%/14%) in the absence (N = 112) versus presence (N = 34) of ≥1 risk factors; leukaemia‐free survival was affected by TP53 VAF ≥22% (p < 0.01). Such information might inform treatment decision‐making in MDS‐del(5q) regarding allogeneic stem cell transplant.

Abstract Venetoclax + hypomethylating agent (Ven‐HMA) is currently the standard frontline therapy for older/unfit patients with newly diagnosed acute myeloid leukemia (ND‐AML). Our objective in the current retrospective study of 301 adult patients (median age 73 years; 62% de novo) with ND‐AML was to identify molecular predictors of treatment response to Ven‐HMA and survival; European LeukemiaNet (ELN) genetic risk assignment was favorable 15%, intermediate 16%, and adverse 69%. Complete remission, with (CR) or without (CRi), count recovery, was documented in 182 (60%) patients. In multivariable analysis, inclusive of mutations only, “favorable” predictors of CR/CRi were NPM1 (86% vs. 56%), IDH2 (80% vs. 58%), and DDX41 (100% vs. 58%) and “unfavorable” TP53 (40% vs. 67%), FLT3‐ ITD (36% vs. 63%), and RUNX1 (44% vs. 64%) mutations; significance was sustained for each mutation after adjustment for age, karyotype, and therapy‐related qualification. CR/CRi rates ranged from 36%, in the presence of unfavorable and absence of favorable mutation, to 91%, in the presence of favorable and absence of unfavorable mutation. At median follow‐up of 8.5 months, 174 deaths and 41 allogeneic stem cell transplants (ASCT) were recorded. In multivariable analysis, risk factors for inferior survival included failure to achieve CR/CRi (HR 3.4, 95% CI 2.5–4.8), adverse karyotype (1.6, 1.1–2.6), TP53 mutation (1.6, 1.0–2.4), and absence of IDH2 mutation (2.2, 1.0–4.7); these risk factors were subsequently applied to construct an HR‐weighted risk model that performed better than the ELN genetic risk model (AIC 1661 vs. 1750): low ( n = 130; median survival 28.9 months), intermediate ( n = 105; median 9.6 months), and high ( n = 66; median 3.1 months; p < .001); survival in each risk category was significantly upgraded by ASCT. The current study identifies genotype signatures for predicting response and proposes a 3‐tiered, CR/CRi‐based, and genetics‐enhanced survival model for AML patients receiving upfront therapy with Ven‐HMA.

Background: The 2022 European LeukemiaNet (ELN) genetic-risk stratification for acute myeloid leukemia (AML), assigns favorable prognosis to t(8;21)(q22;q22.1)/ RUNX1:: RUNX1T1, inv(16)(p13.1q22) or t(16;16)(p13.1;q22)/ CBFB:: MYH1, NPM1 mutations without FLT3-ITD or adverse karyotype, and bZIP in-frame CEBPA mutations (Döhner , Blood, 2022 ). This risk stratification was derived from intensively treated patients; accordingly, prognostication in ELN favorable genetic risk AML, following venetoclax and hypomethylating agent (VEN-HMA) therapy, remains unclear and was the subject of the current study. Methods: Under an institutional review board approved minimum risk protocol, the Mayo Clinic database was searched to identify AML patients with favorable genetic risk, who received treatment with VEN-HMA in the frontline setting. All patients received at least one cycle of either azacitidine 75 mg/m 2 days 1-7 or decitabine 20 mg/m 2 days 1-5 with VEN dose adjusted based on azole antifungal prophylaxis. Genetic risk stratification and treatment response were assessed according to the 2022 ELN criteria. Survival was estimated from the time of VEN-HMA treatment start to last follow-up or death. Results: Patient characteristics A total of 46 newly-diagnosed AML patients with ELN 2022 favorable genetic risk [ NPM1 mutation, n=36 (78%), CEPBA bZIP mutation, n=7 (15%) and t(8;21)(q22;q22.1)/ inv(16)(p13.1q22), n=4 (9%)] received a median of 4 cycles (range 1-32) of VEN-HMA. Median age was 71 years, with 63% males, and 87% de novo AML. Additional mutations frequently involved TET2 in 17/43 (40%), DNMT3A in 14/45 (31%), SRSF2 in 10/43 (23%), K/NRAS in 10/45 (22%), IDH1 in 8/46 (17%), FLT3-TKD in 7/46 (15%), ASXL1 in 6/43 (14%) and IDH2 in 6/46 (13%),of informative cases.Myelodysplasia (MDS)-related gene mutations ( ASXL1, RUNX1, BCOR, EZH2, SRSF2, U2AF1, SF3B1, STAG2, and/or ZRSR2) were present in 15 of 40 (38%) of patients (93% males). Predictors of response Of the 39 (85%) patients that achieved complete remission, with (CR) ( n=24; 52%), or without count recovery (CRi) ( n=15; 33%); CR/CRi rates were not significantly higher in patients with NPM1 mutations (89%), t(8;21)(q22;q22.1)/ inv(16)(p13.1q22) (75%), or CEPBA bZIP mutations (67%) ( p=0.37). Among patients achieving CR/CRi, measurable residual disease by multiparametric flow cytometry was negative in 15 of 16 (94%) of evaluable cases after cycles 1 or 2. In addition, NPM1 qPCR was negative in 15 of 24 (63%) informative patients. Median time to response was 1.2 months with median response duration of 9.4 months. CR/CRi rates were significantly higher in females vs males (100% vs 76%, p=0.01), and in the absence vs presence of MDS-related gene mutations (96% vs 60%, p=0.004). Multivariable analysis confirmed superior response in the absence of MDS-related gene mutations ( p=0.04). Predictors of survival At a median follow-up of 10.6 months (range; 1.1-51 months), 21 patients (46%) have died, 9 relapsed (23% of those achieving CR/CRi), and 6 (13%) underwent allogeneic hematopoietic stem cell transplant. Median overall survival was 21 months with 1/2/3-year survival rates of 65%/41%/41% (Figure 1a); median relapse-free survival (RFS) was not reached; 1/2/3-year RFS rates were 81%/66%/57% (Figure 1b). Overall survival was superior in patients achieving CR/CRi (23 months vs 5.6 months; p&lt;0.01), in females vs males (not reached vs 9.7 months; p&lt;0.01), and in the absence of MDS-related gene mutations (not reached vs 5.6 months; p=0.01) (Figure 1c). Subsequent multivariable analysis identified female gender ( p=0.01), and absence of MDS-related mutations ( p=0.17) as independent predictors of superior survival. Similar results were obtained when analysis was restricted to NPM1 mutated patients. Conclusions: In the current retrospective study, VEN-HMA therapy in elderly/unfit AML patients with ELN 2022 favorable genetic risk, resulted in response rates that were comparable to those previously appreciated from published reports of patients receiving intensive induction therapy; however, follow-up in the current study was too short to accurately assess long-term overall and relapse-free survival impact. Our study also highlights the adverse prognosis retained by MDS-related gene mutations.

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

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

Background: The anti-apoptotic protein Mcl-1 contributes to the pathophysiology of certain B-cell malignancies and AML, and dependence on Mcl-1 is associated with resistance to venetoclax. Efforts to target Mcl-1 through direct inhibition have faced challenges due to cardiovascular toxicities. Voruciclib, a potent oral CDK9 inhibitor (CDK9i), was shown to indirectly downregulate Mcl-1 protein levels and synergize with venetoclax in preclinical models in lymphoid and myeloid malignancies. In solid tumors, voruciclib maximum tolerated dose (MTD) was defined as 350 mg with continuous daily dosing, and 600 mg when used on days 1-14 on a 21-day cycle. This phase 1 study is the first to evaluate the safety, dose-limiting toxicities (DLT), preliminary efficacy, pharmacokinetics, and pharmacodynamics of voruciclib in R/R hematologic malignancies (NCT03547115). Methods: Patients (pts) with relapsed B-cell NHL, CLL, or AML aged ≥18 years who had ECOG performance status ≤1, disease progression after standard therapies, adequate hepatic and renal function, and no prior CDK9i were eligible. The study followed a 3+3 design and DLTs were assessed in Cycle 1. Voruciclib was administered daily continuously at a starting dose of 50 mg on a 28-day cycle (Cohort I). After 2 DLTs were observed at 100 mg in AML pts, dosing was changed to daily on days 1-14 on a 28-day cycle (Cohort II). Also, pts with prior allogeneic transplant were excluded and dose escalation (100, 150, 200 mg) proceeded separately in AML and B-cell malignancies. Disease response was assessed by investigators using the Lugano, 2008 iwCLL, and 2017 ELN criteria. Results: 40 pts were enrolled: 21 AML, 19 NHL (9 DLBCL, 3 CLL, 3 MCL, 3 FL and 1 MZL). Cohort I enrolled 16 pts, 8 each at 50 mg and 100 mg. Cohort II enrolled 24 pts (17 AML and 7 B-cell malignancies), including 6 at 100 mg, 7 at 150 mg, and 11 at 200 mg. Dose escalation in Cohort II did not reach the MTD and was stopped at 200 mg, a dose that achieved plasma concentrations sufficient for target inhibition. Median age was 70 years (range 40-90), 72.5% of pts were ≥65 years, and 77.5% had ECOG performance status = 1. Pts had a median of 3 prior therapies (range, 1-8). Median duration on drug was 5 weeks (range 1-22). Drug-related serious adverse events (AEs) were reported in Cohort I only. Two pts with AML had a DLT of Grade (Gr) 3 interstitial pneumonitis at 100 mg; both had had allogeneic transplant and active graft versus host disease, one of whom also had a concurrent Gr 3 differentiation syndrome. One pt with DLBCL at 50 mg had Gr 3 hypoxemic respiratory failure in Cycle 4. In Cohort II, no DLTs were observed and there were no non-hematologic Gr 3-5 drug-related AEs. In the overall population, the most common AEs were diarrhea (30%), nausea (25%), anemia (22.5%), fatigue (22.5%), constipation (17.5%), dizziness (15%) and dyspnea (15%) [Table 1). One pt with AML had Gr 3 hyperbilirubinemia. There was no evidence of drug-related neutropenia in pts with NHL. No significant cardiovascular AEs were observed. One pt with AML in Cohort I achieved a morphologic leukemia-free state. At 200 mg, 5 of 10 AML pts (50%) had stable disease. Voruciclib pharmacokinetics was dose proportional, mean accumulation ratio was 2.4, mean T max was 4 hours, and at 200 mg, steady state C max was 925 ng/mL and mean C trough was 442 ng/mL (~1 microM). Analysis of Mcl-1 protein expression in normal lymphocytes by flow cytometry showed a trend of decrease in on-treatment samples compared to pre-treatment. Consistent with this, RNA-Seq analysis of 3 paired CLL samples confirmed rapid (after 6 hours) downregulation of Mcl-1 mRNA transcript in the malignant B-cells. Furthermore, scRNA-Seq analysis of 2 longitudinal AML samples demonstrated downregulation of MYC transcriptional program and oxidative phosphorylation in circulating AML blasts, both evident 24 hours after start of voruciclib and ongoing at C1D15. Conclusions: Voruciclib at doses up to 200 mg administered on 14 consecutive days on a 28-day cycle was well tolerated, with no DLTs observed, and no cardiovascular toxicities. There was no significant myelosuppression in pts with B-cell malignancies. As the safety profile suggested non-overlapping toxicities with venetoclax, the study is now evaluating voruciclib in combination with venetoclax in pts with R/R AML to exploit dual inhibition of Bcl-2 and Mcl-1.