The Growing Role of the BH3 Mimetic Drug Venetoclax in the Therapy of Acute Myeloid Leukemia

Elvira Pelosi, Germana Castelli and Ugo Testa.

Department of Oncology, Istituto Superiore di Sanità, Rome, Italy.

Introduction

Apoptosis is an important biological process in health and disease and is regulated by BCL-2 family proteins.
BCL-2 was identified as an oncogene resulting from a translocation between chromosomes 14 and 18 that promotes malignant lymphomagenesis. In the early ’90s, BCL-2 was identified as a pro-survival protein preventing apoptotic cell death.
These proteins exert either a pro-apoptotic or anti-apoptotic effect, and their activity balance is crucial for controlling cell viability.[1] The main activity of these proteins consists in controlling the activation of caspases, the proteolytic enzymes executioner of the apoptotic process.[1] BCL-2 is a member of the anti-apoptotic protein family expressing BCL-2-like homology domains 1-4, which includes, in addition to BCL-2, BCL-XL, BCL-W, BCL2-A1, and MCL-1.[1] The BCL-2 family protein also comprises some proteins with pro-apoptotic activity, including the pro-apoptotic activators (BID, BIM, and PUMA), the pro-apoptotic effectors (BAK and BAX), and the sensitizer effector (NOXA).[1] All these proteins form the intrinsic apoptotic pathway. Intrinsic apoptosis is executed in response to cellular damage and most anti-cancer agents (Figure 1).

---

Figure 1. Members of the BCL-2 family subdivided according to their function in proapoptotic sensitizers, proapoptotic activators, proapoptotic effectors and antiapoptotic proteins and their role in the intrinsic apoptotic pathway. The effect of BH3 mimetics, such as Venetoclax, is also shown.

---

BH domains play a key role in controlling the activity of BCL-2 proteins and the apoptotic process. BH3 domains are expressed by all the members of the BCL-2 family; BAX and BAK proteins express all four BH domains; the activator (BIM and BID) and sensitizer (NOXA) proteins contain only BH3 domains. BH3 domain-mediated interactions between apoptotic and anti-apoptotic BCL-2 family members play an essential role in the control of apoptotic response: thus, the interaction of the sensitizer and anti-apoptotic BCL-2 family members triggers apoptosis by enabling activator proteins, not more bound to anti-apoptotic BCL-2 family members, to interact with BAK/BAX effectors on the outer mitochondrial membrane, resulting in the damage of this membrane with pore formation and membrane permeabilization, the release of cytochrome C from mitochondria, caspase activation and full induction of the apoptotic machinery.[1]
Several BH3 mimetic drugs have been synthesized, including venetoclax (VEN, ABT-199), navitoclax (ABT-263), and ABT-737. These drugs selectively bind to the BH3 domain present on anti-apoptotic proteins and, through this mechanism, induce the release of bound pro-apoptotic proteins and apoptosis. Navitoclax binds to BCL-2, BCL-X_L, and BCL-W and, for this reason, induces in vivo platelet lowering; this side effect is not observed with VEN that selectively binds to BH3 expressed on BCL-2, thus sparing platelets.[2]
Preclinical studies have supported the clinical evaluation of VEN as a potential anti-leukemic drug. These studies have shown that AML bulk cells and leukemic stem cells (LSCs) depend on BCL for their survival and BCL-2 inhibition causes cell death in AML cells.[3,4] In vitro studies have shown that AML cell lines, primary patient AML samples, and primary murine xenografts are very sensitive to treatment with VEN, with induction of cell death.[3] Furthermore, mitochondrial studies using BH3 profiling showed that VEN treatment acts at the mitochondrion level, correlating with leukemic cell cytotoxicity.[3] Other studies have provided evidence that VEN's cytotoxic effect is also exerted at the level of LSCs, the cells that initiate and maintain the leukemic process.[4] In fact, it was shown that LSCs are present in a condition of quiescence, with a low energy state and reactive oxygen species *ROS; these cells are thus dependent on oxidative phosphorylation, whose activity is dependent on oxidative phosphorylation and thus vulnerable to BCL/2 inhibition using VEN.[4]
In initial clinical studies, VEN was evaluated in monotherapy, but due to its limited effects, it was evaluated in association with current anti-leukemic treatments in subsequent studies.

Venetoclax in newly diagnosed AML

The use of venetoclax in the treatment of newly diagnosed AMLs (ND-AMLs) was mainly tested in patients with comorbidities precluding intensive chemotherapy or in those older than 65-70 years. In these studies, VEN was used in association with azacytidine (AZA) or decitabine (DEC), or low-dose Ara C (LDAC). All these regimens have shown a good safety profile and low 30-day mortality (Table 1).

---

Table 1. Clinical studies evaluating Venetoclax-based regimens in newly diagnosed AML patients.

---

Combination with hypomethylating agents. DiNardo and coworkers have explored two groups of ND elderly AMLs, one of 23 patients treated with 7-day AZA+VEN and the other of 22 patients treated with 5-day DEC+VEN: in both treatment arms, a CR+Cri, with incomplete count recovery (CRi), rate of 60% was observed.[5] Subsequently, the same authors reported the exploration of a large number of patients (145 ND-AML patients at least 65 years old). In this group of patients, two VEN doses were explored, 400 mg and 800 mg, showing better results for the 400 mg dosage at the level of safety profile and therapeutic efficacy; using the 400 mg VEN dosage, a global CR+CRi rate of 73% was observed; patients with high-risk cytogenetics showed a CR+CRi rate of 60%. In addition, the median duration of CR+Cri was 11.3 months, and the mean OS was 17.5 months for all patients and was not reached for those treated with VEN at 400 mg.[6]
The low-dose Ara-C (LDAC) regimen based on LDAC and VEN was explored in a group of 82 older AML patients not eligible for IC (49% of these patients had s-AML and 32% had poor-risk cytogenetic features): 54% of these patients achieved a CR+CRi, with a median OS of 10.1 months and DOR of 8.1 months.[7] In patients without previous hypomethylating agents (HMA) exposure, CR+CRi was 62%, with a mean overall survival of 13.5 months.[7]
Two randomized clinical trials showed the superiority of the combined 7-day AZA+VEN compared to 7-dayAZA+placebo and LDAC+VEN compared to LDAC+placebo. Thus, a large phase III clinical trial (VIALE-A trial) involved the study of 431 elderly AML patients randomized to receive 7-day AZA+VEN or 7-day AZA+placebo: CR+CRi rate was 66% vs. 28%, and the median OS was 14.7 months vs. 9.6 months in 7-day AZA+VEN and 7-day AZA+placebo, respectively, thus showing a consistent benefit deriving from AZA+VEN administration compared to AZA alone.[8] In the second trial, 211 elderly AML patients were randomized to receive LDACc+VEN of LDAC+placebo: CR+CRi were 48% and 13% for LDAC+VEN and LDAC+placebo, respectively; median OS was 7.2 months for LDAC+VEN compared to 4.1 months for LDAC+placebo.[9] Interestingly, 164 patients of the VIALE-A trial with CR+CRi were explored for MRD status as assessed by multiparametric flow cytometry: with a cut-off of <10^-3, 41% of patients displayed an MRD-negative condition, and 59% were MRD-positive; in MRD-negative patients after a follow-up of 12 months DoR, EFS and OS were not reached, whereas in MRD-positive patients DoR, EFS and OS were 81%, 83% and 94%.[10]
Winters et al. have reported a “real-world” experience of VEN with AZA in 33 newly diagnosed AML patients; these patients received the same treatment as another group of AML patients enrolled in phase I/II study.[11] The CR+CRi rate was 63% for out-trial patients, compared to 85% of the trial patients; the mOS was 381 days for out-trial patients, compared to 880 days for trial patients.[11] Prior exposure to hypomethylating agents was associated with poor outcomes. On 14 patients out-trial, the MRD was evaluated after treatment: 4/14 were MRD-negative and displayed sustained remission; 10/14 were MRD-positive, and 6 of these patients showed sustained remission, while the 4 other patients relapsed.[11]
Pollyea et al. reported the results of a phase Ib study of VEN with azacitidine (84 patients) or decitabine (31 patients): the CR+Cri rate was 71% for VEN+AZA and 74% for VEN+DEC; the median duration of CR/Cri was 21.9 months and 15.0 months, and the median OS was 16.4 months and 16.2 months, respectively.[12]
In order to improve the rate and the duration of responses, more intensive treatments were associated with VEN. DiNardo et al. have explored the safety and the therapeutic impact of the administration of DEC 20mg/m² for 10 days and VEN 400 mg daily for induction, followed by DEC for 5 days with oral VEN 400 mg for consolidation in a group of 70 elderly ND-AML patients and 15 untreated s-AML patients: ORR was 89% and 80% for ND-AML and s-AML patients, respectively; OS was 18.1 months for ND-AML and 7.8 months for s-AML.[13] A more comprehensive report on these patients, including 80 ND-AML and 20 untreated s-AML treated with 10-day DEC+VEN, explored the therapeutic responses in genomic subgroups of patients: patients bearing NPM1, FLT3, IDH1/IDH2, TP53, RUNX1, N/KRAS mutations shower CR+CRi rates ranging from 70 to 88%; patients with ASXL1 and TP53 mutations displayed 55% and 50% of CR+CRi.[14] Median OS values for ND-AML patients were not-reached for NPM1-mutant, 29.6 months for IDH1/IDH2-mutant, 24.5 months for FLT3-mutant, 24.5 months for ASXL1-mutant, 16.1 for RUNX1-mutant, 12.1 months for N/KRAS-mutant and 5.4 months for TP53-mutant AMLs. A propensity score-matched analysis of DEC10-VEN vs. intensive chemotherapy stratified by risk of treatment-related mortality (TRM) showed that DEC10-VEN offers better outcomes compared to intensive chemotherapy in terms of CR+CRi rate, lower rate of relapse, and longer overall survival.[15]
Combination with Reduced Intensity Regimens. Kadia et al. have evaluated in a group of 60 older (≥60 years) AML patients a peculiar therapeutic regimen based on VEN added to cladribine (CLAD) plus LDAC, alternating with AZA; after treatment, 93% of patients had CR+CRi, 84% were MRD-negative, and after 22 months of follow-up the median OS and DFS were not reached.[16] These results support the conclusion that VEN+CLAD/LDAC alternating with VEN+AZA is an effective regimen in older or unfit patients with ND-AML.
A recent study reported the initial evaluation of AZA+VEN in combination with the anti-CD47 mAb magrolimab in a small cohort of 17 ND-AML patients older/unfit or high-risk (14/17).[17] 94% of treated patients achieved a CR+CRi condition, with 55% of MRD negativity. Although these observations involve few patients, the results observed in these patients are promising given their frequent TP53 mutant status (50% of cases) and high-risk condition.
Combination with Intensive Chemotherapy. Other studies have explored the safety and efficacy of VEN administered with intensive chemotherapy. In this context, the first study by Chua et al. explored VEN in association with a modified intensive chemotherapy protocol (CAVEAT, an attenuated 7+3 regimen consisting of 5 days of cytarabine and 2 days of idarubicin, 5+2) in 51 AML patients with a median age of 72 years; the overall CR+CRi rate among both de novo and secondary AML (sAML) patients was 72%; CR+CRi rate was 97% in ND-AML.[18] After a median follow-up of about 2 years, mOS for the overall study population was 11.2 months; markedly longer mOS was observed among de novo AMLs (31.3 months) compared to sAMLs (6.1 months).[18] The safety profile for the patients receiving up to 400 mg VEN was usually good, with a number of infectious adverse events for their frequency and grade, expected for AML patients of this age undergoing intensive chemotherapy treatment; thus, these results showed that therapy with VEN in combination with intensive chemotherapy is feasible in an elderly AML population.[18] A phase I/II clinical study enrolled 29 ND-AML patients of a wide range of ages, suitable for intensive chemotherapy, who were treated with FLAG-IDA (fludarabine, cytarabine, G-CSF, and idarubicin) combined with VEN with an ORR of 97%, 90% of CR+CRi, 96% of MRD negativity; 69% of these patients proceeded to allo-HSCT.[19] A recent study reported the results of an expanded cohort of ND-AML patients enrolled in the FLAG-IDA+VEN study; the results on response rate, CR rate, and MRD status confirmed those previously observed.[20] Estimated 24-months EFS and OS were 64% and 76%, respectively.[20] A post-hoc propensity score-matched analysis of prospective clinical trials in patients of the Texas University supported the conclusion that VEN plus intensive chemotherapy improved event-free survival; however, overall survival did not differ significantly compared to that observed in patients treated with intensive chemotherapy alone.[21]
Other studies have explored VEN in association with standard 7+3 induction chemotherapy. In an initial study, Stone et al. reported the preliminary results on 10 DN-AML patients treated with 7+3 chemotherapy (cytarabine at days 1-7 and daunorubicin at days 2-4) In association with VEN (400 mg was the maximum tolerated dose): the ORR was 100%, and 75% of the patients achieved MRD-negative remissions.[22,23] Very recently, Wang et al. reported the results of phase II, a single-arm trial enrolling 33 ND-AML patients aged 18-60 years treated with 7+3 induction chemotherapy and VEN at 400 mg.[24] After one cycle of therapy, a CR rate of 91% was observed; 97% of these patients in CR had an MRD-negative status; after 11 months of follow-up, 97% of OS and 1-year EFS was 72%.[24]
Recent studies have explored the combination of VEN with CPX-351; CPX-351 is a dual-drug liposomal encapsulation of cytarabine (ara-C) and daunorubicin at 5:1 molar ratio that is approved for the treatment of newly diagnosed therapy-related AML or AML with myelodysplasia-related changes. Drug synergism/additivity in preclinical studies provided a rationale for combining CPX-351 + VEN clinically. A first study based on only 5 newly diagnosed AML patients with adverse prognosis showed a CR/CRi rate of 80%; 80% of these patients were transitioned to hematopoietic stem cell transplantation.[25] The second study explored 31 patients with de novo AML, with a median age of 74 years, predominantly with poor-risk disease; CR+CRi was observed in 57 of patients; MRD-negativity was observed in 75% of patients who achieved CR or CRi; survival data are not yet mature.[26]

Venetoclax in refractory/relapsing AMLs

About sixty percent of newly diagnosed patients with AML receiving frontline induction/consolidation chemotherapy achieve a complete response, but 30-40% of these patients relapse. Relapsed or refractory AMLs (R/R-AMLs) remain a population with very adverse prognosis and necessitate improved therapeutic options. The successful use of Venetoclax as frontline treatment supported the exploration of its possible use for the treatment also of R/R-AML patients (Table 2).

---

Table 2. Clinical studies evaluating Venetoclax-based regimens in relapsing/refractory AML patients.

---

Combination with Hypomethylating Agents or Reduced-Intensity Chemotherapy. In an initial phase II study, VEN was tested as a single agent in 32 R/R-AML patients and produced a limited CR+Cri rate of 19%.[27]
An initial study by DiNardo and coworkers reported the clinical results of treatment based on VEN+HMA or VEN+LDAC AML patients, using protocols like those used in elderly de novo AML patients, in 39 R/R-AML patients, showing objective responses in 21% of cases, including patients with IDH1/2, RUNX1 and TP53 mutations.[28] In another initial study, Aldoss et al. reported a “real-world” analysis of 33 R/R-AML patients treated with either VEN+AZA or VEN+DEC, reporting a CR+CRi rate of 51%.[29] 53% of CR+CRi responders were MRD-negative by multicolor flow cytometry.[29] Higher responses to the treatment were observed among patients with refractory de novo AMLs and therapy-related AMLs, compared to those with secondary AMLs.[29] The 1-year overall survival for all patients was 53% and was longer for patients with de novo than with secondary or therapy-related AMLs.[29]
Subsequent studies have been performed using two different strategies: (i) some studies explored standard VEN-based regimens using this agent in combination with HMAs or with LDAC; (ii) other studies have evaluated new VEN-based regimens. The first type of study involved, in most instances, the limited experience of single centers and did not imply controlled clinical trials. In this context, the study involving the largest number of R/R-AML patients (86) was performed by Stahl et al.[30] In this study, 86 R/R-AML patients were treated either with VEN+AZA or with VEN+LDAC: VEN+AZA resulted in higher response rates than VEN+LDAC (49% vs. 15%) and in a significantly longer OS (25 vs. 3.9 months). In addition, mutations in NMP1 were associated with higher response rates, whereas adverse cytogenetics and mutations in TP53, KRAS/NRAS and SF3B1 were associated with worse OS.[30]
Other studies largely confirmed these findings. Labrador et al. reported the results observed in 51 AML patients in the context of the PATHEMA group who were treated with either VEN+AZA or VEN+DEC, or VEN+LDAC: the frequency of responders (CR+PR) patients was higher for VEN+AZA (32%) compared to VEN+DEC (13%) or VEN+LDAC (0%).[31] The patients enrolled in this study had very poor risk features and were heavily pre-treated.[31] Feld et al. reported the results of their single-institution experience in the treatment of 39 R/R-AML patients treated with VEN+HMA; 39% of these patients achieved a CR/CRi, with an OS of 8.1 months; responders to treatment were enriched for TET2, IDH1/IDH2 mutations, while non-responders were associated with FLT3 and RAS mutations.[32] Wang reported the results on 40 R/R AML patients treated with VEN-based therapy, showing 22% of CRs; patients with RUNX1 mutations showed a significantly longer OS; patients with intermediate-risk cytogenetics had better outcomes compared to those with adverse-risk cytogenetics.[33]
Combination with New Therapeutic Regimens. The type 2 studies were based on the development of new therapeutic regimens more appropriate for the treatment of a high-risk AML population, such as R/R-AML. DiNardo et al. have developed a therapeutic regimen involving a longer 10-day administration of decitabine; it was hypothesized that VEN with 10-day DEC could lead to an enhanced therapeutic response in both ND-AMLs and R/R-AMLs.[13] Thus, patients with R/R-AML received DEC 20mg/m² for 10 days with oral VEN 400 mg daily for induction, followed by DEC for 5 days with daily VEN consolidation. The overall response rate was 62%, with a median overall survival of 7.8 months and a duration of response of 16.8 months.[13] The most significant rates of response and the longer OS were observed in patients with diploid cytogenetics, NPM1, and IDH1/IDH2 mutations.[14] Maiti et al. recently reported the long-term outcomes of major genomic subgroups of these RR-AML patients treated with DEC10-VEN: CR/CRi rates in patients with mutations of NPM1 were 68%, of IDH1/IDH2 50%, of FLT3 42%, of RUNX1 45%, of TP53 30% and of KRAS/NRAS 26%; the longer OS was observed in patients with mutated IDH1/IDH2 (16.9 months), RUNX1 (13.7 months) and NPM1 (12.4 months), but shorter in patients with mutant ASXL1 (9.0 months), FLT3 (6.4 months), KRAS/NRAS (6.0 months) and TP53 (4.5 months).[15] Maiti et al. have compared the outcomes of 64 R/R-AML patients treated with DEC10-VEN to a cohort of 130 patients comparable for age and other baseline characteristics treated with standard intensity chemotherapy regimens commonly used for these patients: DEC10-VEN displayed significantly higher responses compared to the IC cohort, including ORR (60% vs. 36%) (MRD negativity assessed by multiparametric flow cytometry (28% vs. 13%) and CR+CRi (19% vs. 6%). Multivariate analysis supported a longer median event-free survival (5.7 vs. 4.5 months) and median overall survival (6.8 months vs. 4.7 months) for DEC10+VEN compared to IC.[34]
A phase I/II clinical study enrolled 39 R/R-AML patients suitable for intensive chemotherapy treatment who were treated with FLAG-IDA (fludarabine, cytarabine, G-CSF, and idarubicin) combined with VEN: an overall response rate of 70-75% and a CR+CRi rate of 61-75% was observed.[19] After a median follow-up of 12 months, median OS was not reached; 46% of patients proceeded to allogeneic HSCT with a one-year survival post-HSCT of 78%.[19] Wolach et al. have performed a real-world analysis of 24 R/R-AML patients undergoing treatment with FLAG-IDA+VEN and reported a CR+Cri rate of 72% (91% for patients post-HSCT) and with an OS of 50% at 12 months.[35] A registry-based study with FLAG-IDA+VEN corroborated the results observed in the other studies with CR/CRi rate of 69%, MDR negativity in 22% of patients, and 6-months OS of 10.5 months.[36]
A recent study reported the preliminary results of a phase I/II clinical trial based on the administration of AZA+VEN in association with an anti-CD47 mAb (Magrolimab) in older ND-AMLs and in R/R-AMLs. Phase II of the study involved 8 VEN-naïve R/R-AML patients and 13 VEN-treated R/R-AML patients: in the former, a CR of 63% and an OS not reached were observed; in the latter ones, a CR of 27% and an OS of 3.1 months were observed.[17]
Ravandi and coworkers reported the preliminary data on the safety and efficacy of combination therapy based on DEC+VEN+ASTX727 (cytidine deaminase inhibitor cedazuridine) in 13 R/R-AML patients: ORR was 45%, with 30% of CR+CRi and an OS of 7.2 months.[37]
A recent study evaluated the safety and the clinical efficacy of CPX-351 in combination with VEN, using an approach similar to that adopted for newly diagnosed AML patients. 26 R/R-AMl patients were treated with CPX-351 and VEN, achieving a CR+CRi rate of 46%, with an MRD negativity by flow cytometry of 75% and with an mOS of 7.1 months (in the responding patients, the mOS was 26.9 months) and a 1-year OS of 39%.[25] In addition, achieving measurable residual disease (MRD) absence was associated with better OS in these patients, with an mOS of 26.9 months in MRD-negative compared to 2.6 months in MRD-positive patients.[25]
The treatment of IDH-mutant AMLs changed in the last years due to the introduction in the therapy of IDH1 and IDH2-specific pharmacologic inhibitors. A recent phase III trial in elderly IDH1-mutant AML patients, who were ineligible for intensive induction chemotherapy, showed a consistent clinical benefit deriving from the administration of ivosidenib (an inhibitor of mutant IDH1) and azacytidine, with a mean OS of 24 months.[38] Lachowicz et al. have performed a phase I/II clinical study involving the administration of ivosidenib with VEN, with or without AZA, to a group of either ND-AMLs or s-AMLs or R/R-AMLs.[39] The available results are relative to 8 R/R-AML patients: IDH1 mutation clearance following treatment was achieved in 50% of these patients; at 24 months, 50% of these patients survived and MRD negativity correlated with improved survival.[39] A clinical study reported the results of the clinical activity of EC10-VEN on a small cohort of 11 IDH2-mutant R/R-AML patients, with an ORR of 82%, a CR-CRi rate of 54%, MRD-negativity as assessed by Flow cytometry of 54% and by PCR of 36%; after a follow-up of 21 months, 1-year OS was 59% and the mean overall survival 14.7 months.[40] A preliminary report on 7 IDH2-mutant R/R-AML patients showed the therapeutic efficacy of the triplet based on the administration of AZA+VEN+Enasidenib: 86% of these patients displayed CR+CRi, including those with prior exposure to AZA or Enasidenib; the median OS was not reached, and the 1-year OS was 67%.[41]

Venetoclax as Maintenance Therapy

Outcomes of Selected AML Subtypes Following Venetoclax-Based Therapy

Safety Profile of Venetoclax

Venetoclax Metabolism and Drug Interactions

Venetoclax Resistance

The most consistent limitation of the therapy of AMLs with VEN is the short duration and the development of resistance.[127] Therefore, understanding the mechanisms of resistance to this drug is of fundamental importance for the development of new strategies able to bypass these therapeutic blocks and for the definition of new drug combinations.[127] Various mechanisms of resistance to VEN-based regimens have been identified in AML cells. However, the two most important are represented by dependencies on alternative anti-apoptotic BCL-2 family members and the selection of activating kinase mutations.[127]
The mechanism related to the development of dependencies on alternative anti-apoptotic BCL-2 proteins seems to be particularly relevant. These alternative dependencies include different anti-apoptotic mediators, such as BCL-2-A1, MCL-1, and BCL-XL and are involved in primary and adaptive VEN resistance mechanisms (Figure 2).

---

Figure 2. Mechanism of action of and resistance to Venetoclax. In the absence of overexpression of MCL-1, BCL-XL and BCL2-A1, binding of the BH3 mimetic Venetoclax to BCL-2 determines the release of bound BH3-only proteins, such as BIM, inducing the interaction between these displaced BH3-only proteins and BAK/BAX with consequent activation of a BAK/BAK complex (BAK/BAX oligomerization); this activated BAK/BAX complex determines an increase of the mitochondrial outer membrane permeability (MOMP) with consequent release of cytochrome c from the mitochondria into the cytoplasm and activation of the apoptotic process through caspase activation. In the presence of increased levels of the antiapoptotic proteins MCL-1, BCL-XL and BCL2-A1, the proapoptotic effect of Venetoclax in inhibited through a mechanism involving sequestration of displaced BH3-only proteins, thus preventing the capacity of these proteins to bind and to activate BAK/BAX and thus blocking the proapoptotic effect of Venetoclax.

---

In this context, a role particularly relevant is played by MCL-1 as the main mechanism of VEN resistance. A fundamental study by Bhatt and co-workers explored the mechanisms of acquired resistance to BH3 mimetic antagonists of BCL-2 and MCL-1 using AML patient-derived xenograft (PDX) models: these models involved AML cells that have acquired resistance to VEN following treatment with this drug and AML cells that were constitutively resistant to VEN.[128] BH3 profiling studies showed that BH3 mimetic resistance is characterized by decreased mitochondrial apoptotic priming, as measured both in primary AML samples and in PDX models, due to alterations at the level of BCL-2 family proteins, variable from one case to another.[126] In VEN-resistant AML cells, BCL-2 sequestration of pro-apoptotic proteins, necessary to confer BCL-2 dependence, was reduced. This phenomenon was not due to a decreased expression of BCL-2 or BIM after the acquisition of resistance but to the sequestration of BIM at the level of MCL-1; an opposite phenomenon is observed in cells resistant to MCL-1 antagonists, with BIM sequestration at the level of BCL-2.[128] This finding has considerable implications for therapy based on combinations of BCL-2 and MCL-1 antagonists since it implies that the concurrent rather than the sequential administration of these inhibitors is more effective.[128]
Two initial studies showed that MCL-1 upregulation renders leukemic cells resistant to VEN. Thus, Pan et al. provided evidence that a pan-BCLK-2 inhibitor (-)BI97D6 potently induced apoptosis through intrinsic pathway activation by disrupting MCL-1/BIM and BCL-2/BAX interactions; importantly, this pan-BCL-2 inhibitor, as a single agent, effectively overcame AML cell apoptosis resistance mediated by MCL-1 in AML cells.[129]
The exploration of VEN-resistant AML cell lines derived through chronic exposure to VEN showed that the upregulation of MCL-1 and BCL-XL drives drug resistance; targeting MCL-1 and/or BCL-X_L restored the sensitivity of these leukemic cells to VEN.[130]
A consistent number of studies supported the role of MCL-1 in VEN resistance mechanisms.
Ewold and coworkers reported a side-by-side comparison of three different BH3-mimetics targeting BCL-2 or MCL-1, or BCL-X_L; they drove the conclusion that MCL-1 may be a more prevalent therapeutic target than BCL-2 in AML. Interestingly, MCL-1 BH3-mimetics induced displacement of the BH3-only protein BIM and BAK, resulting in BAK-dependent apoptosis; in contrast, VEN-induced cell death was mediated by BAX rather than BAK.[131] This finding supports distinct non-redundant molecular functions of BCL-2 and MCL-1 in AML cells.
The analysis in vitro of a large panel of AML cell lines and of primary AML samples co-cultured with bone marrow mesenchymal stromal cells showed that inhibition of MCL-1, whose expression is weak compared to that of BCL-2, induces apoptosis of AML cells and strongly synergizes with VEN.[132]
VU661013 is a selective and potent MCL-1 inhibitor that destabilizes the association between BIM and MCL-1, induces AML c ells apoptosis, and is active in VEN-resistant and patients-derived xenografts.[133] Importantly, BH3 profiling of patient samples and ex vivo drug-sensitivity assays predicted sensitivity to BCL-2 or MCL-1 inhibitors and showed the benefit deriving from the combination of the two types of inhibitors.[133]
Studies in pre-clinical models of AMLK supported the double targeting of MCL-1 and BCL-2. Particularly, the analysis of primary AML samples, including those with poor risk genotypes, showed the efficacy of the contemporaneous MCL-1 and BCL-2 targeting in the induction of leukemic cell apoptosis.[134] Furthermore, co-targeting of MCL-1 and BCL-2 was more effective against the leukemic compartment compared to normal hematopoietic stem/progenitor cells, thus supporting a therapeutic window of activity and a tolerable safety profile at the level of the hematopoietic system.[134] Importantly, BCL-2 and MCL-1 co-targeting prolonged animal survival in xenograft models of AML and suppressed patient-derived leukemia but not normal hematopoietic cells in the bone marrow of engrafted animals.[134]
A recent study showed that co-targeting of BCL-2 and MCL-1 was highly effective in inhibiting leukemic stem cells derived from AMLs resistant to VEN or relapsed after VEN-based therapy, irrespective of genetic alterations and cytogenetic alterations.[127] Interestingly, enhanced antileukemia activity was also observed in a PDX model of monocytic leukemia, a leukemia subtype known to be resistant to VEN-based therapy.[135]
Importantly, a recent study provided evidence that the BCL-2 and MCL-1 co-targeting was effective not only against VEN-resistant AML cells but also against chemotherapy-resistant cells. Accordingly, S63845, an MCL-1 inhibitor, in combination with VEN, effectively inhibits AML cells that have acquired resistance to cytarabine, thus supporting an evaluation of this drug combination in relapsed/refractory AML patients.[136]
Proteasome inhibition may represent a new strategy to antagonize MCL-1 activity in cancer cells via transactivation of the MCL-1 antagonist NOXA.[137] Interestingly, proteasome inhibitors strongly synergize with VEN in inducing apoptosis of cancer cells.[137] However, this synergistic combination was not yet evaluated in preclinical models of AML.
The increased dependency on MCL-1 observed constitutively in some AMLs or following VEN treatment may be related to activation of the MAPK signaling pathway, which induces stabilization of MCL-1 protein and prevents its degradation.[138-139] RAS-MAPK activation is a major mechanism of acquired VEN resistance, mediated by MCL-1 upmodulation and that can be abrogated by MCL-1 inhibition; rapid clonal selection of RAS-mutated clones was observed in some AML patients treated with VEN-containing regimens and represented an important mechanism underlying development of VEN resistance.[140]
RAS pathway mutations, such as those occurring at the level of KRAS and PTPN11 genes, induce VEN resistance to AML cells, related to a mechanism involving MCL-1 and BCL-X_L upmodulation; these AML subtypes are sensitive to MCL-1 inhibitors.[138] Studies in AML cell lines have shown that VEN resistance was reproduced through transduction of G12D KRAS or A72D PTPN11 mutants; G12D KRAS-transduced cells displayed decreased BCL-2 and BAX levels, associated with increased MCL-1 and BCL2-A1 levels.[138] Only MCL-1 inhibitors, but not BCL-2 or BCL-X_L inhibitors, could reduce the viability of these leukemic cells.[138] The combination of VEN+MCL-1 inhibitors showed synergy in inducing apoptosis of leukemic cells.[138]
RAS pathway activation, observed in RAS- and PTPN11-mutated cases, induces the activation of multiple sources of energy for cell survival, including fatty acid and amino acid metabolism, glycolysis and upregulation of OXPHOS.[141] Furthermore, AMLs harboring a PTPN11 mutation frequently display a monocytic differentiation phenotype,[142] usually associated with dependency on MCL-1 and thus scarcely sensitive to VEN-mediated BCL-2 inhibition.[143]
In line with these findings, inhibition of the MAPK signaling pathway using MEKK/MEK2 inhibitors synergizes with VEN to induce apoptosis of AML cells.[144] Furthermore, this drug combination induced downregulation of MCL-1 levels and disrupted the binding of BIM to both MCL-1 and BCL-2, thus releasing BIM that was able to initiate the apoptotic process.[144] The observations provided a rationale for the combinatorial blockade of MEK and BCL-2 pathways in AML subsets characterized by KRAS, NRAS, PTPN11, and FLT3-ITD mutations.
Ongoing phase I clinical trials are evaluating different MCL-1 inhibitor-based treatments for AML patients, including the combination therapies with VEN (NCT03672695, NCT02979366, and NCT04629443).
Interestingly, a recent phase It study showed that VEN with low-dose Navitoclax was well tolerated and had promising efficacy in patients with relapsed/refractory acute lymphoblastic leukemia or lymphoblastic lymphoma.[145] Therefore, an ongoing clinical study is evaluating the combination of VEN, Navitoclax, and Decitabine in relapsed/refractory AML patients previously treated with VEN (NCT05222984).

Conclusions

1. Kale J, Osterlund EJ, Andrews DW. BCL-2 family proteins: changing partners in the dance towards death. Cell Death Differ 2018; 25: 65-80. https://doi.org/10.1038/cdd.2017.186 PMid:29149100 PMCid:PMC5729540
   
2. Soners AJ, Lavenon JD, Boghaert ER, et al. ABT-199, a potent and selective BCL-2 inhibitor, achieves antitumor activity while sparing platelets. Nature Med 2013; 19: 202-208. https://doi.org/10.1038/nm.3048 PMid:23291630
   
3. Pan R, Hogdal LJ, Benito JM, Bucci D, Han L, Borthakur G, Cortes J, DeAngelo DJ, Debose L, et al. Selective BCL-2 inhibition by ABT-199 causes on-target cell death in acute myeloid leukemia. Cancer Discov 2014; 4: 362-375. https://doi.org/10.1158/2159-8290.CD-13-0609 PMid:24346116 PMCid:PMC3975047
   
4. Laagdinou ED, Sach A, Callahan K, Rossi RM, Neering SJ, Minhajuddin M, Ashton JM, Pei S, Grose V, O'Dwyer KM, et al. BCL-2 inhibition targets oxidative phosphorylation and selectively eradicates quiescent humabn leukemic stem cells. Cell Stem Cell 2013; 12: 329-341. https://doi.org/10.1016/j.stem.2012.12.013 PMid:23333149 PMCid:PMC3595363
   
5. DiNardo CD, Pratz KW, Letai A, Jonas BA, Wei AH, Thirman M, Arellano M, Frattini MG, Kantarjian H, Popovic R, et al. Safety and preliminary efficacy of venetoclax with decitabine or azacytidine in elderly patients with previously untreated acute myeloid leukemia: a non-randomized, open-label, phase 1b study. Lancet Oncol 2018; 19(2): 216-228. https://doi.org/10.1016/S1470-2045(18)30010-X
   
6. DiNardo CD, Pratz K, Pullarkat V, Jonas BA, Arellano M, Becker PS, Frankfurt O, Konopleva M, Wei AH, Kantarjian HM, et al. Venetoclax combined with decitabine or azacytidine in treatment-naïve, elderly patients with acute myeloid leukemia. Blood 2019; 133(1): 7-17. https://doi.org/10.1182/blood-2018-08-868752 PMid:30361262 PMCid:PMC6318429
   
7. Wei AH, Strickland SA, Hou JZ, Fiedler W, Lin TL, Walter RB, Enjeti A, Tiong IS, Savona M, Lee S, et al. Venetoclax comvined with low-dose cytarabine for previously untreated patients with acute myeloid leukemia: results from a phase Ib/II study. J Clin Oncol 2019; 37(15): 1277-1284. https://doi.org/10.1200/JCO.18.01600 PMid:30892988 PMCid:PMC6524989
   
8. DiNardo CD, Jonas BA, Poullarkat V, Thirman MJ, Garcia JS, Wei AH, Konopleva M, Dohner H, Letai A, Fenaux P, et al. Azacitidine and venetoclax in previously untreated acute myeloid leukemia. N Engl J Med 2020; 383(7): 617-629. https://doi.org/10.1056/NEJMoa2012971 PMid:32786187
   
9. Wei AH, Montesinos P, Ivanov V, DiNardo CD, Novak J, Laribi K,Kim I, Stevens DA, Fiedler W, Pagoni M, et al. Venetoclax plus LDAC for newly diagnosed AML ineligible for intensive chemotherapy: a phase 3 randomized placebo-controlled trial. Blood 2020; 135(24): 2137-2145. https://doi.org/10.1182/blood.2020004856 PMid:32219442 PMCid:PMC7290090
   
10. Pratz KW, Jonas BA, Pullarkat V, Recher C, Schuh AC, Thirman MJ, Garcia JS, DiNardo CD, Vorobyev V, Fracchiolla NS, et al. Measurable residual disease response and prognosis in treatment-naïve acute myeloid leukemia with venetoclax and azacytidine. J Clin Oncol 2022; 40(8): 855-865. https://doi.org/10.1200/JCO.21.01546 PMid:34910556
    
11. Winters AC, Gutman JA, Purev E, Nakic M, Tobin J, Chase S, Kaiser J, Lile L, Boggs C, Halsema K, et al. Real-world experience of venetoclax with azacytidine for untreated patients with acute myeloid leukemia. Blood Adv 2019; 3(20): 2911-2920. https://doi.org/10.1182/bloodadvances.2019000243 PMid:31648312 PMCid:PMC6849960
    
12. Pollyea DA, Pratz K, Letai A, Jonas BA, Wei AH, Pullarkat V, Konopleva M, Thirman MJ, Arellano M,Becker PS, et al. Venetoclax with azacitidine or decitabine in patients with newly diagnosed acute myeloid leukemia: long term follow-up from a phase 1b study. Am J Hematol 2021; 96: 208-217. https://doi.org/10.1002/ajh.26039 PMid:33119898
    
13. DiNardo CD, Maiti A, Rausch CR, Pemmaraju N, Naqvi K, Daver NG, Kadia TM, Borthakur G, Ohanina M, Alvarado Y, et al. 10-day decitabine with venetoclax for newly diagnosed intensive chemotherapy ineligible, and relapsed or refractory acute myeloid leukemia: a single-centre, phase 2 trial. Lancet Hematol 2020; 7(10): e724-e736. https://doi.org/10.1016/S2352-3026(20)30210-6
    
14. DiNardo CD, Rausch CR, Pemmaraju N, Garcia-Manero G, Ohanian M, Daver N, Issa GC, Borthakur G, Ravandi F, Alvarad Y, et al. Phase II trial of ten-day decitabine plus venetoclax (DEC10-VEN) in acute myeloid leukemia: updated outcomes in genomic subgroups. Blood 2021.
    
15. Maiti A, Qiao W, Sasaki K, Ravandi F, Kadia TM, Jabbour EJ, Daver NG, Borthakur EJ, Garcia-Manero G, Pierce SA, et al. Venetoclax with decitabine vs intensive chemotherapy in acute myeloid leukemia: a propensity score matched analysis stratified by risk of treatment-related mortality. Am J Hematol 2021; 96: 282-291. https://doi.org/10.1002/ajh.26061 PMid:33264443 PMCid:PMC8128145
    
16. Kadia TM, Reville PK, Wang X, Rausch CR, Borthakur G, Pemmaraju N, Daver NG, DiNardo CD, Sasaki K, Issa GC, et al. Phase II study of venetoclax added to cladribine plus low-dose cytarabine alternating with 5-azacitidine in older patients with newly diagnosed acute myeloid leukemia. J Clin Oncol 2022; in press. https://doi.org/10.1200/JCO.21.02823 PMid:35704787
    
17. Daver N, Konopleva M, Maiti A, Kadia TM, DiNardo CD, Loghavi S, Pemmaraju N, Jabbour EJ, Montalban-Bravo G, Tang G, et al. Phase I/II study of azacytidine (AZA) with venetoclax (VEN) and magrolimab (Magro) in patients (pts) with newly diagnosed older/unfit or high-risk acute myeloid leukemia (AML) and relapsed/refractory (R/R) AML. Blood 2021; abst 616. https://doi.org/10.1182/blood-2021-153638
    
18. Chua CC, Roberts AW, Reynolds J, Fong CY, Ting SB, Salmon JM, MacRaild S, Ivey A, Tiong IS, Fleming S, et al. Chemotherapy and venetoclax in elderly acute myeloid leukemia trial (CAVEAT): a phase Ib dose-escalation study of venetoclax combined with modified intensive chemotherapy. J Clin Oncol 2020; 38(30): 3506-3517. https://doi.org/10.1200/JCO.20.00572 PMid:32687450
    
19. DiNardo C, Lachowiez CA, Takahashi K, Loghavi S, Xiao L, Kadia T, Daver N, Adeoti M, Short NJ, Sasaki K, et al. Venetoclax combined with FLAG-IDA induction and consolidation in newly diagnosed and relapsed or refractory acute myeloid leukemia. J Clin Oncol 2021; 39(25): 2768-2778. https://doi.org/10.1200/JCO.20.03736 PMid:34043428 PMCid:PMC8407653
    
20. DiNardo CD, Lachowiez CA, Takahashi K, Loghavi S, Kadia T, Daver N, Xiao L, Adeoti M, Short NJ, Sasaki K, et al. Venetoclax combined with FLAG-IDA induction and consolidation in newly diagnosed acute myeloid leukemia. Am J Hematol 2022; 97(8): 1035-1043. https://doi.org/10.1002/ajh.26601 PMid:35583199
    
21. Lachowiezv CA, Reville PK, Kantarjian H, Jabbour E, Bothakur G, Daver N, Loghavi S, Furudate K, Xiao L, Pierce S, et al. Venetoclax combined with induction chemotherapy in patients with newly diagnosed acute myeloid leukemia: a post-hoc, propensity score-matched, cohort study. Lancet Hematol 2022; 9(5): e350-e360. https://doi.org/10.1016/S2352-3026(22)00076-X
    
22. Stone RM, De Angelo DJ, Galinsky I. Phasi I trial of escalating doses of the Bcl-2 inhibitor venetoclax in combination with daunorubicin/cytarabine induction and high dose cytarabine consolidation in previously untreated adults with acute myeloid leukemia (AML). Blood 2019; 134: 3908-3908. https://doi.org/10.1182/blood-2019-124966
    
23. Stone RM, De Angelo DJ, Letai AG. Maximal tolerated dose of the BCL-2 inhibitor venetoclax in combination with daunorubicin/cytarabine induction in previously untreated adults with acute myeloid leukemia (AML). Blood 2020; 136: 40-41. https://doi.org/10.1182/blood-2020-140646
    
24. Wang H, Mao L, Yang M, Qian P, Lu H, Tong H. Ventoclax plus 7+3 daunorubicin and cytarabine therapy as first-line treatment for adults with acute myeloid leukemia: a multicentre, single-arm, phase 2 trial. Lancet Hematol 2022; 9(6): E415-E424. https://doi.org/10.1016/S2352-3026(22)00106-5
    
25. Kim K, Kantarjian H, Borthakur G, Takahashi K, Short NJ, DiNardo CD, Jabbour EJ, Chien K, Daver N, Pemmaraju N, et al. A phase II study of CPX-351 plus venetoclax in patients with relapsed/refractory (R/R) or newly diagnosed acute myeloid leukemia (AML). Blood 2021; 138 (suppl 1): 1275. https://doi.org/10.1182/blood-2021-154148
    
26. Uy GL, Pullarkat VA, Baratam P, Stuart RK, Walter RB, Winer ES. Lowerintensity CPX-351 + venetoclax for patients with newly diagnosed AML who are unfit for intensive chemotherapy. J Clin Oncol 2022; 40, suppl. 16: 7031. https://doi.org/10.1200/JCO.2022.40.16_suppl.7031
    
27. Konopleva M, Pollyea DA, Potluri J, Chyla B, Hogdal L, Busman T, McKeegan E, Hamed Salem A, Zhu M, Ricker JL, et al. Efficacy and biological correlates of response in a phase II study of venetoclax monotherapy in patients with acute myelogenous leukemia. Cancer Discover 2016; 6(10): 1106-1117. https://doi.org/10.1158/2159-8290.CD-16-0313 PMid:27520294 PMCid:PMC5436271
    
28. DiNardo CD, Rausch CR, Benton C, Kadia T, Jain N, Pemmaraju N, Daver N, Covert W, Marx KR, Mace M, et al. Clinical experience with the BCL2-inhibitor venetoclax in combination therapy for relapsed and refractory acute myeloid leukemia and related myeloid malignancies. Am J Hematol 2018; 93(3): 401/407. https://doi.org/10.1002/ajh.25000 PMid:29218851
    
29. Aldoss I, Yang D, Aribi A, Ali H, Sandhu K, Malki M, Mei M, Salhotra A, Khaled S, Nakamura R, et al. Efficacy of the combination of venetoclax and hypomethylating agents in relapsed/refractory acute myeloid leukemia. Haematologica 2018; 103: e405. https://doi.org/10.3324/haematol.2018.188094 PMid:29545346 PMCid:PMC6119155
    
30. Stahl M, Menghrajani K, Derkach A, Chan A, Xia W, Glass J, King AC, Daniyan AF, Famulare C, Cuello Bm, et al. Clinical and molecular predictors of response and survival following venetoclax therapy in relapsed/refractory AML. Blood Adv 2021; 5(5): 1552-1564. https://doi.org/10.1182/bloodadvances.2020003734 PMid:33687434 PMCid:PMC7948282
    
31. Labrador J, Saiz-Rodriguez M, de Miguel D, de Laiglesia A, Rodriguez-Medina C, Vidriales MB, Perez-Encina M, Sanchez-Sanchez MJ, Cuello R, Rodan-Perez A, et al. Use of venetoclax in patients with relapsed or refractory acute myeloid leukemia: the PETHEMA registry experience. Cancers 2022; 14(7): 1734. https://doi.org/10.3390/cancers14071734 PMid:35406512 PMCid:PMC8997036
    
32. Feld J, Tremblay D, Dougherty M, Czaplinska T, Sanchez G, Brady C, Kremyanskaya M, Bar-Natan M, Keyzner A, Marcellino BK, et al. Safety and efficacy: clinical experience of venetoclax in combination with hypomethylating agents in both newly diagnosed and relapsed/refractory advanced myeloid malignancies. Hemasphere 2021; 5(4): e549. https://doi.org/10.1097/HS9.0000000000000549 PMid:33718803 PMCid:PMC7951133
    
33. Wang YW, Tsai CH, Lin CC, Tien FM, Chen YW, Lin HY, Yao M, Lin YC, Lin CT, Cheng CL, et al. Cytogenetics and mutations could predict outcome in relapsed and refractory acute myeloid leukemia patients receiving BCL-2 inhibitor venetoclax. Ann Hematol 2020; 99(3): 501-511. https://doi.org/10.1007/s00277-020-03911-z PMid:31965269
    
34. Maiti A, DiNardo CD, Qiao W, Kadia TM, Jabbour EJ, Rausch CR, Daver NG, Short NJ, Borthakur G, Pemmaraju N, et al. Ten-day decitabine with venetoclax versus intensive chemotherapy in relapsed or refractory acute myeloid leukemia: a propensity score-matched analysis. Cancer 2021; 127(22): 4213-4220. https://doi.org/10.1002/cncr.33814 PMid:34343352
    
35. Wolach O, Frisch A, Shargian L, Yeshurun M, Apel A, Vainstein V, Moshe Y, Shimony S, Amit O, Bar-On Y, et al. Venetoclax in combination with FLAG-IDA-based protocol for patients with acute myeloid leukemia: a real-world analysis. Ann Hematol 2022; in press. https://doi.org/10.1007/s00277-022-04883-y PMid:35732976
    
36. Shahswar R, Beutel G, Klement P, Rehberg A, Gabdoulline R, Koenecke C, Markel D, Eggers H, Eder M, Stadler M, et al. FLAG-IDA salvage chemotherapy combined with a seven-day course of venetoclax (FLAVIDA) in patients with relapsed/refractory acute leukemia. Brit J Haematol 2020; 188: e1-e30A https://doi.org/10.1111/bjh.16268 PMid:31681986 PMCid:PMC7116720
    
37. Ravandi F, Abuasab T, Alvarado Valero Y, Issa GC, Islam R, Short NJ, Yilmaz M, Jain N, Masarova L, Kornblau SM, et al. Phase 2 study of ASTX727 (cedazuridine/decitabine) plus venetoclax (ven) in patients with relapsed/refractory acute myeloid leukemia (AML) or previously untreated, elderly patients (pts) unfit for chemotherapy. J Clin Oncol 2022; 40: 16 suppl.1, abst. 7037. https://doi.org/10.1200/JCO.2022.40.16_suppl.7037
    
38. Montesinos P, Recher C, Vives S, Zarzycka E, Wang J, Bertani G, Heuser M, Calado RT, Schuh AC, Yeh SP, et al. Ivosidenib and azacytidine in IDH1-mutated acute myeloid leukemia. N Engl J Med 2022; 386: 1519-1531. https://doi.org/10.1056/NEJMoa2117344 PMid:35443108
    
39. Lachowiez CA, Suen Garcia J, Borthakur G, Loghavi S, Zeng Z, Tippett GD, Kadia TM, Masarova L, Yilmaz M, Maiti A, et al. A phase Ib/II study of ivosidenib with venetoclax +/- azacytidine in IDH1-mutated hematologic malignancies. J Clin Oncol 2022; 40(16): suppl. Abst. 7018. https://doi.org/10.1200/JCO.2022.40.16_suppl.7018
    
40. Venugopal S, Maiti A, DiNardo CD, Loghavi S, Daver NG, Kadia TM, Rausch CR, Alvarado Y, Ohanian M, Sasaki K, et al. Decitabine and venetoclax for IDH1/2-mutated acute myeloid leukemia. Am J Hematol 2021; 96(5): E154-E157. https://doi.org/10.1002/ajh.26122 PMid:33580980 PMCid:PMC8237705
    
41. Venugopal S, Takahashi K, Daver N, Maiti A, Borthakur G, Loghavi S, Short NJ, Ohanian M, Masarova L, Issa G, et al. Efficacy and safety of enasidenib and azacytidine combination in patients with IDH2 mutated acute myeloid leukemia and not eligible for intensive chemotherapy. Blood Cancer J 2022; 12:10. https://doi.org/10.1038/s41408-021-00604-2 PMid:35078972 PMCid:PMC8789767
    
42. Chua CC, Hammond D, Kent A, Tiong IS, Konopleva MY, Pollyea DA, DiNardo CD, Wei AH. Treatment-free remission after ceasing venetoclax-based therapy in patients with acute myeloid leukemia. Blood Adv 2022; in press. https://doi.org/10.1182/bloodadvances.2022007083 PMid:35511730 PMCid:PMC9278306
    
43. Pollyea DA, Winters A, McMahon C, Schwartz M, Jordan CT, Rabinovitch R, Abbott D, Smith CA and Gutman JA. Venetoclax and azacytidine followed by allogeneic transplant results in excellent outcomes and may improve outcomes versus maintenance therapy among newly diagnosed AML patients older than 60. Bone Marrow Transpl 2022; 57: 160-166. https://doi.org/10.1038/s41409-021-01476-7 PMid:34645926
    
44. Kent A, Pollyea DA. Winters A, Jordan CT, Smith C, Gutman JA. Venetoclax is safe and tolerable as post-transplant maintenance therapy for AML patients at high risk for relapse. Blood 2020; 134: 2410. https://doi.org/10.1182/blood-2020-138832
    
45. Bazinet A, Kantarjian H, Borthakur G, Yilmaz M, Bose P, Jabbour EJ, Alvarado Y, Chien KS, Pemmaraju N, Takahashi K, et al. A phase II study of 5-azacitidine (AZA) and venetoclax as maintenance therapy in patients with acute myeloid leukemia (AML) in remission. Blood 2021; 138: supll.1: 2326. https://doi.org/10.1182/blood-2021-150573
    
46. Bazinet A, Kantarjian H, Borthakur G, Yilmaz M, Bose P, Jabbour EJ, Alvarado Y, Chien KS, Pemmaraju N, Takahashi K, et al. Phase 2 study of azacytidine (AZA) and venetoclax (VEN) as maintenance therapy for acute myeloid leukemia (AML) patients in remission. J Clin Oncol 2022; 40(16). Suppl. Abst. E19018. https://doi.org/10.1200/JCO.2022.40.16_suppl.e19018
    
47. Lachowiez CA, Loghavi S, Kadia TM, Daver N, Borthakur G, Pemmaraju N, Naqvi K, Alardo V, Yilmaz M, Short N, et al. Outcomes of older patients with NPM1-mutated AML: current treatment and the promise of venetoclax-based regimens. Blood Adv 2020; 4(7): 1311-1320. https://doi.org/10.1182/bloodadvances.2019001267 PMid:32251497 PMCid:PMC7160266
    
48. Tiang IS, Dillon R, Ivey A, The TC, Nguyen P, Cummings N, Taussig DC, Latif AL, Potter NE, Runglall M, et al. Brit J Haematol 2021; 192(6): 1026-1030. https://doi.org/10.1111/bjh.16722 PMid:32458446 PMCid:PMC8048658
    
49. Begenberger JM, Kornblau SM, Piercall WE, Lena R, Cow D, Shi CX, Mantel J, Ahmann G, Gonzalez JM, Choudhary A, et al. BCL-2 family proteins and 5-azacytidine-sensitizing targets and determinants of response in myeloid malignancies. Leukemia 2014; 28: 1657-1665. https://doi.org/10.1038/leu.2014.44 PMid:24451410 PMCid:PMC4131248
    
50. Jones CL, Stevens BM, D'Alessandro A, Reisz Á, Culp-Hill R, Nemkov T, Pei S, Khan N, Adane B, Ye H, et al. Inhibition of amino acid metabolism selectively targets human leukemia stem cells. Cancer Cell 2018; 34: 724-740.e4. https://doi.org/10.1016/j.ccell.2018.10.005 PMid:30423294 PMCid:PMC6280965
    
51. Pollyea DA, AStevens BM, Jones CL, Winters A, Pei S, Minhajuddin M, D'Alessandro A, Culp-Hill R, Riemondy KA, Gillen AE, et al. Venetoclax with azacytidine disrupts energy metabolism and targets leukemia stem cells in patients with acute myeloid leukemia. Nat Med 2018; 24: 1859-1866. https://doi.org/10.1038/s41591-018-0233-1 PMid:30420752 PMCid:PMC7001730
    
52. Stevens BM, Jones CL, Pollyea DA, Culp-Hill R, D'Alessandro A, Winters A, Krug A, Abbott D, Goosman M, Pei S, et al. Fatty acid metabolism underlies venetoclax resistance in acute myeloid leukemia stem cells. Nat Cancer 2020; 1(12): 1176-1187. https://doi.org/10.1038/s43018-020-00126-z PMid:33884374 PMCid:PMC8054994
    
53. Jones CL, Stevens BM, Pollyea DA, Culp-Hill R, Reisz JA, Nemkov T, Gehrke S, Gamboni F, Krug A, Winters A, et al. Nicotinamide metabolism mediates resistance to venetoclax in relapsed acute myeloid leukemia stem cells. Cell Stem Cell 2020; 27(5): 748-764.e4. https://doi.org/10.1016/j.stem.2020.07.021 PMid:32822582 PMCid:PMC7655603
    
54. Bisaillon R, Moison C, Thiollier C, Krosl J, Bordeleau ME, Lehnertz B, Lavallée JP, MacRae C, Boucher G, et al. Genetic characterization of ABT-199 sensitivity in human AML. Leukemia 2020; 34: 63-74. https://doi.org/10.1038/s41375-019-0485-x PMid:31300747
    
55. Kontro M, Kumar A, Majumder MM, Eldfors S, Parson A, Pemovska T, et al. HOX gene expression predicts response to BCL-2 inhibition in acute myeloid leukemia. Leukemia 2017; 31: 301-319. https://doi.org/10.1038/leu.2016.222 PMid:27499136
    
56. Chesnokov MS, Borhani S, Halasi M, Arbieva Z, Zhan I, Gartel AL. FOXM1-AKT-positive regulation loop provides venetoclax resistance in AML. Front Oncol 2021; 11: 696532. https://doi.org/10.3389/fonc.2021.696532 PMid:34381718 PMCid:PMC8350342
    
57. Wu HC, Rérolle D, Berthier C, Hleihel R, Sakamoto T, Quentin S, Benhenda S, Morganti C, Wu C, Conte L, et al. Actinomycin D targets NPM1c-primed mitochondria to restore PML-driven senescence in AML therapy. Cancer Discovery 2021; 11(12): 3198-3213. https://doi.org/10.1158/2159-8290.CD-21-0177 PMid:34301789 PMCid:PMC7612574
    
58. Ranieri R, Piangiani G, Perriello VM, Marra A, Cardinali V, Pierangeli S, Milano F, Gianfriddo I, Brunetti L, Martelli MP, Falini B. Current status and future perspectives in targeted therapies of NPM1-mutated AML. Leukemia 2022; in press. https://doi.org/10.1038/s41375-022-01666-2 PMid:36008542 PMCid:PMC9522592
    
59. Fisher MA, Friedlander SY, Arrate MP, Chang H, Gorska AE, Fuller RD, Ramsey HE, Kaskyap T, Argueta C, Debler S, et al. Venetoclax response is enhanced by selective inhibitor of nuclear export compounds in hematological malignancies. Blood Adv 2020; 4(3): 586-598. https://doi.org/10.1182/bloodadvances.2019000359 PMid:32045477 PMCid:PMC7013257
    
60. Pangiani G, Gagliardi A, Mezzaroma F, Rocchio F, Tini V, Bigema B, Sportolketti P, Caruso S, Marra A, Peruzzi S, et al. Prolonged XPO1 inhibition is essential for antileukemic activity in NPM1-mutated AML. Blood Adv 2022; in press. https://doi.org/10.1182/bloodadvances.2022007563 PMid:36037515
    
61. Klossowski S, Miao H, Kempinska K, Wu T, Purohit T, Kim E, Linhares BM, Cghen D, Jih G, Perkey E, et al. Menin inhibitor MI-3454 induces remission in MLL1-rearranged and NPM1-mutated models of leukemia. J Clin Invest 2020; 130(2): 981-997. https://doi.org/10.1172/JCI129126 PMid:31855575 PMCid:PMC6994154
    
62. Uckelmann HJ, Kim SM, Wong EM, Hatton C, Giovinazzo H, Gadrey JY, Krivstov AV, Rucker FG, Dohner K, McGeehan GM, et al. Therapeutic targeting of preleukemia cells in a mouse model of NPM1 mutant acute myeloid leukemia. Science 2020; 367(6477): 586-590. https://doi.org/10.1126/science.aax5863 PMid:32001657 PMCid:PMC7754791
    
63. Carter BZ, Tao W, Mak PY, Ostermann LB, Mak D, McGeehan G, et al. Menin inhibition decreases Bcl-2 and synergizes with venetoclax in NPM1/FLT3-mutated AML. Blood 2021; 138: 1637-1641. https://doi.org/10.1182/blood.2021011917 PMid:34232981
    
64. Fiskus W, Boettcher S, Daver N, Mill CP, Sasaki K, et al. Effective menin inhibitor-based combinations against AML with MLL rearrangement or NPM1 mutation (NPM1c). Blood Cancer J 2022; 12: 5. https://doi.org/10.1038/s41408-021-00603-3 PMid:35017466 PMCid:PMC8752621
    
65. Venugopal S, Maiti A, DiNardo CA, Loghavi S, Daver DG, Kadia TM, Rausch CR, Alvarado Y, Ohanion M, Sasaki K, et al. Decitabine and venetoclax for IDH1/2-mutated acute myeloid leukemia. Am J Hematol 2021; 96(5): E154-E157. https://doi.org/10.1002/ajh.26122 PMid:33580980 PMCid:PMC8237705
    
66. Hammond D, Loghavi S, Konopleva M, Response patterns and MRD by flow cytometry and NGS in patients with mutant-IDH acute myeloid leukemia treated with venetoclax in combination with hypomethylating agents. Blood 2020; 136(suppl. 1): 35-36. https://doi.org/10.1182/blood-2020-141380
    
67. Pollyea DA, DiNardo CA, Arellano ML, Pigneux A, Fiedler W, Konopleva M, Rizzieri DA, Smith D, Shinagawa A, Memoli R, et al. Impact of venetoclax and azacytidine in treatment-naïve patients with acute myeloid leukemia and IDH 1-2 mutations. Cancer Res 2022; 28: 2753-2761. https://doi.org/10.1158/1078-0432.CCR-21-3467 PMid:35046058
    
68. Montesinos P, Recher C, Vives S, Zarzycka E, Wang J, Bertani G, Heuser M, Calado RT, Schuh AC, Yeh SP, et al. Ivosidenib and zacitidine in IDH1-mutated acute myeloid leukemia. N Engl J Med 2022; https://doi.org/10.1056/NEJMoa2117344 PMid:35443108
    
69. Botton S, Chol S, Marchione DM, et al. Molecular characterization of clinical response in patients with newly diagnosed AML treated with ivosidenib + azacytidine compared to placebo + azacytidine. J Clin Oncol 2022; 40(suppl. 16): 7019. https://doi.org/10.1200/JCO.2022.40.16_suppl.7019
    
70. DiNardo CD, Schuh AC, Stein EM, Montesinos P, Wei AH, de Botton S, Zeidan AM, Fathi AT, Kantarjian HM, Bennett JM, et al. Enasidenib plus azacytidine versus azacytidine alone in patients with newly diagnosed, mutant-IDH2 acute myeloid leukemia (AG221-AML-005): a single-arm, phase 1b and randomized phase 2 trial. Lancet Oncol 2021; 22(11): 1597-1608. https://doi.org/10.1016/S1470-2045(21)00494-0
    
71. Lachowiez CA, Bethakur G, Loghavi S, Zeng Z, Kadia TM, Masarova L, Takahashi K, Tippett GD, Smith S, Garcia JS, et al. A phase Ib/II study of ivosidenib with venetoclax +/- azacytidine in IDH1-mutated myeloid malignancies. J Clin Oncol 2021; 39(suppl. 15): 7012. https://doi.org/10.1200/JCO.2021.39.15_suppl.7012
    
72. Lachowiez AC, Garcia JS, Borthakur G, Loghavi S, Zeng Z, Tippett GD, Kadia TM, Masorava L, Yilmaz M, Maiti A, et al. A phase Ib/II study of ivosidenib with venetoclax +/- azacytidine in IDH1-mutated hematologic malignancies. J Clin Oncol 2022; 40(suppl. 16):7018-7018. https://doi.org/10.1200/JCO.2022.40.16_suppl.7018
    
73. Venugopal S, Takahashi K, Daver N, Maiti A, Borthakur G, Loghavi S, Short NJ, Ohanian M, Masarova L, Issa G, et al. Efficacy and safety of enasidenib and azacytidine combination in patients with IDH2 mutated acute myeloid leukemia and not eligible for intensive chemotherapy. Blood Cancer J 2022; 12(1): 10. https://doi.org/10.1038/s41408-021-00604-2 PMid:35078972 PMCid:PMC8789767
    
74. Chan SM, Cameron C, Chatelin S, Gupta V, More D, Minden MD, Murphy T, Schimman AD, Schuh AC, Sibai H, et al. Enasidenib in combination with venetoclax in IDH2-mutated myeloid malignancies: preliminary results of the phase I/II Enaven-AML trial. Blood 2021; 138(suppl.1): 1263. https://doi.org/10.1182/blood-2021-153660
    
75. Aldoss I, Yand D, Pillai R, Sanchez JF, Mei M, Aribi A, Ali H, Sandhu K, Al Malki M, Salhotra A, et al. Association of leukemia genetics with response to venetoclax and hypomethylating agents in relapsed/refractory acute myeloid leukemia. Am J Hematol 2019; 94: E253-E255. https://doi.org/10.1002/ajh.25567 PMCid:PMC8855495
    
76. Chan SM, Thomas D, Coprces-Zimmerman MR, Xavy S, Rastogi S, Hong WJ, Zhao F, Medeiros BC, Tyvoll DA, Majeti R. Isocitrate dehydrogenase 1 and 2 mutations induce BCL-2 dependence in acute myeloid leukemia. Nat Med 2015; 21: 178-184. https://doi.org/10.1038/nm.3788 PMid:25599133 PMCid:PMC4406275
    
77. Konopleva M, Thirman M, Pratz KW, Letai AG, Recher C, Pullarkat VA, et al. Results of venetoclax and azacytidine combination in chemotherapy ineligible untreated patients with acute myeloid leukemia with FLT3 mutations. Blood 2020; 136: 8-10. https://doi.org/10.1182/blood-2020-134100
    
78. Konopleva M, Thirman MJ, Pratz KW, Garcia JS, Recher C, Pullarkat V, Kantarjian HM, DiNardo CD, Dail M, Duan Y, et al. Impact of FLT3 mutation on outcomes after venetoclax and azacytidine for patients with treatment-naïve acute myeloid leukemia. Clin Cancer Res 2022; in press. https://doi.org/10.1158/1078-0432.CCR-21-3405 PMid:35063965
    
79. DiNardo CD, Tiong IS, Quaglieri A, MacRaild S, Loghavi S, Brown FC, Thijson R, Pomilio G, Ivey A, Salmon JM, et al. Molecular patterns of response and treatment failure after frontline venetoclax in older patients with AML. Blood 2020; 135(11): 791-803. https://doi.org/10.1182/blood.2019003988 PMid:31932844 PMCid:PMC7068032
    
80. Mali RS, Zhang Q, Di Filippis RA, Cavazos A, Kuruvilla A, Roman J, Mody V, Choo E, Dail M, Shah NP, Konopleva M, et al. Venetoclax combines synergistically with FLT3 inhibition to effectively target leukemic cells in FLT3-ITD+ acute myeloid leukemia models. Haematologica 2021; 104(6): 1034-1046. https://doi.org/10.3324/haematol.2019.244020 PMid:32414851 PMCid:PMC8017817
    
81. Brinton LT, Zhang P, Williams K, Canfield D, Orwick S, Sher S. Synergistic effect of BCL2 and FLT3 co-inhibition in acute myeloid leukemia. J Hematol Oncol 2020; 13: 139. https://doi.org/10.1186/s13045-020-00973-4 PMid:33076970 PMCid:PMC7574303
    
82. Zhu R, Li L, Nguyen B, Seo J, Wu M, Seale T. FLT3 tyrosine kinase inhibitors synergize with BCL-2 inhibition to eliminate FLT3/ITD acute leukemia cells through BIM activation. Signal Transduct Target Ther 2021; 6: 186. https://doi.org/10.1038/s41392-021-00578-4 PMid:34024909 PMCid:PMC8141515
    
83. Altman JK, Daver N, Maly J. AML-162: efficacy and safety of venetoclax in combination with gilteritinib for relapsed/refractory FLT3-mutated acute myeloid leukemia: updated analyses of a phase 1b study. Clin Lymphoma Myeloma Leuk 2021; 21: 5285. https://doi.org/10.1016/S2152-2650(21)01684-0
    
84. Dover N, Perl AE, Maly J, Levis M, Ritchie E, Litzow M, McCloskey J, Smith CC, Schiller G, Bradley T, et al. Venetoclax plus geltiritinib for FLT3-mutated relapsed/refractory acute myeloid leukemia. J Clin Oncol 2022; in press. https://doi.org/10.1200/JCO.22.00602 PMid:35849791
    
85. Maiti A, DiNardo CD, Daver NG, Rausch CR, Ravandi F, Kadia TM. Triplet therapy with venetoclax, FLT3 inhibitor and decitabine for FLT3-mutated acute myeloid leukemia. Blood Cancer J 2021; 11:25. https://doi.org/10.1038/s41408-021-00410-w PMid:33563904 PMCid:PMC7873265
    
86. Yilmaz M, Kantarjian H, Short NJ, Reville P, Konopleva M, Kadia T, DiNardo CD, Borthakur G, Pemmarajyu N, Maiti A, et al. Hypomethylating agent and venetoclax with FLT3 inhibitor "triplet" therapy in older/unfit patients with FLT3 mutated AML. Blood Cancer J 2022; 12: 77. https://doi.org/10.1038/s41408-022-00670-0 PMid:35501304 PMCid:PMC9061716
    
87. Yilmaz M, Kantarjian HM, Muftuoglu M, Kadia TM, Konopleva M, Borthakur G, DiNardo CD, Pemmaraju N, Short NJ, Alvarado Y, et al. Quizartinib with decitabine and venetoclax (triplet) is highly active in patients with FLT3-ITD mutated acute myeloid leukemia (AML). J Clin Oncol 2021; 39(suppl. 15): e 19019. https://doi.org/10.1200/JCO.2021.39.15_suppl.e19019
    
88. Short NJ, DiNardo CD, Daver N, Nguyen D, Yilmaz M, Kadia TM, Garcia-Manero G, Issa GC, Huang X, Qiao W, et al. A triplet combination of azacitidine, venetoclax and gilteritinib for patients with FLT3-mutated acute myeloid leukemia: results from a phase I/II study. Blood 2021; 138(suppl. 1): 696. https://doi.org/10.1182/blood-2021-153571
    
89. Post SM, Ma H, Maloney P, Zhang X, Aitken M, Mak PY, Ruvoloi VR, Yasushiro T, Kozaki R, Chan Le, et al. AXL/MERTK inhibitor ONO-7475 potently synergizes with VEN and overcomes VEN resistance to kill FLT3-ITD acute myeloid leukemia. Haematologica 2022; 107: 1311-1322. https://doi.org/10.3324/haematol.2021.278369 PMid:34732043 PMCid:PMC9152975
    
90. Janssen M, Schmidt C, Bruch PM, Blank MF, Rohde C, Waclawiezek A, Heid D, Rendey S, Golluer S, Vierbam L, et al. Venotoclax synergizes with gilteritinib in FLT3 wild type high-risk AML by suppression of MCL1. Blood 2022; in press. https://doi.org/10.1182/blood.2021014241 PMid:35857899
    
91. Ma J, Zhao S; Qiao X, et al. Inhibition of BCL-2 synergistically enhances the antileukemic activity of midostaurin and gilteritinib in preclinical models of FLT3-mutated acute myeloid leukemia. Clin Cancer Res 2019; 68: 15-26. https://doi.org/10.1158/1078-0432.CCR-19-0832 PMid:31320594 PMCid:PMC6858954
    
92. Lachowiez CA, Loghavi S, Furudate K, Montalban-Bravo G, Maiti A, Kadia T, Dever N, Borthakur G, Pemmaraju N, Sasaki K, et al. Impact of splicing mutations in acute myeloid leukemia treated with hypomethylating agents combined with venetoclax. Blood Adv 2021; 5: 2173-2183. https://doi.org/10.1182/bloodadvances.2020004173 PMid:33885753 PMCid:PMC8095152
    
93. Nechiporuk T, Kurtz SE, Nikolova O, Liu T, Jones CL, D'Alessandro A, Culp-Hill R, D'Almeida A, Joshi SK, Rosenberg M, et al. The TP53 apoptotic network is a primary mediator of resistance to BCL2 inhibition in AML cells. Cancer Discover 2019; 9: 910-925. https://doi.org/10.1158/2159-8290.CD-19-0125 PMid:31048320 PMCid:PMC6606338
    
94. Aldoss I, Zhang J, Pillai R, et al. Venetoclax and hypomethylating agents in TP53-mutated acule myeloid leukemia. Br J Haematol 2019; 187: e45-e48. https://doi.org/10.1111/bjh.16166 PMid:31441045 PMCid:PMC6786919
    
95. Kim K, Maiti A, Kadia TM, Ravandi F, Daver N, Pemmaraju N, Borthakur G, Bose P, Issa GC, Short NJ, et al. Outcomes of TP53-mutant acue myeloid leukemia with venetoclax and decitabine. Blood 2020; 136(suppl.1): 33-36. https://doi.org/10.1182/blood-2020-140182
    
96. Pollyea DA, Pratz KW, Wei AH, Pullarkat V, Jonas BA, Recher C, Babu S, Sehuh AC, Dail M, Sun Y, et al Outomes in patients with poor-risk cytogenetics with or without TP53 mutations treated with venetoclax and azacitidine. Clin Cancer Res 2022; in press. https://doi.org/10.1158/1078-0432.CCR-22-1183 PMid:36007102
    
97. Shapiro LC, Mantzaris I, Shashi A, Sica AR, Bachier-Rodriguez L, Kernblum N, Grisham K, Feldman EJ, Verma AK, Brauynschweig I, et al. Low-dose weekly decitabine and venetoclax in TP53-mutated myeloid malignancies. J Clin Oncol 2022; 40(supplk. 15): e19005. https://doi.org/10.1200/JCO.2022.40.16_suppl.e19005
    
98. Gaidzik VI, Teleanu V, Papaemmanuil E, Weber D, Paschka P, Hahn J, Wallrabenstein T, Kolbinger B, Kohne CH, Horst HA, et al. RUNX1 mutations in acute myeloid leukemia are associated with distinct clinic-pathologic and genetic features. Leukemia 2016; 30(11): 2160-2168. https://doi.org/10.1038/leu.2016.126 PMid:27137476
    
99. Quesada AE, Montalban-Bravo G, Luthra R, Patel KP, Sasaki K,Bueso-Rumos CE, Khoury JD, Routbort MJ, Bassett R, Hidago-Lopez JE, et al. Clinico-pathologic characteristics and outcomes of the World Health Organization /WHO) provisional entity de novo acute myeloid leukemia with mutated RUNX1. Mod Pathol 2020; 33: 1678-1689. https://doi.org/10.1038/s41379-020-0531-2 PMid:32238878
    
100. Cherry EM, Abbott D, Amaya M, McMahon C, Schwartz M, Rosser J, Sato A, Schoiwinsky J, Inguva A, Minhajuddin M, et al. Venetoclax and azacytidine compared with induction chemotherapy for newly diagnosed patients with acute myeloid leukemia. Blood Adv 2021; 5(24): 5565-5573. https://doi.org/10.1182/bloodadvances.2021005538 PMid:34610123 PMCid:PMC8714726
     
101. Venugopal S, DiNardo CD, Loghavi S, Qiao W, Ravandi F, Konopleva M, Kadia T, Bhalla K, Jabbour E, Issa GC, et al. Differential prognostic impact of RUNX1 mutations according to frontline therapy in patients with acute myeloid leukemia. Am J Hematol 2022;Sep 10. doi: 10.1002/ajh.26724 https://doi.org/10.1002/ajh.26724 PMid:36087091
     
102. Morsia E, McCullough K, Joshi M, Cook J, Atkhateeb HB, Al-Kali A, Begna K, Elliott M, Hogan W, Litzow M, et al. Venetoclax and hypomethylating agents in acute myeloid leukemia: Mayo Clinic series on 86 patients. Am J Hematol 2020; 95: 1511-1521. https://doi.org/10.1002/ajh.25978 PMid:32833294
     
103. Cai X, Gao L, Teng L, Ge J, Oo ZM, Kumar AR, Gilliland DG, Mason PJ, Tan K, Speck NA. Runx1 deficiency decreases ribosome biogenesis and confers stress resistance to hematopoietic stem and progenitor cells. Cell Stem Cell 2015; 17: 165-177. https://doi.org/10.1016/j.stem.2015.06.002 PMid:26165925 PMCid:PMC4530029
     
104. Mill CP, Fiskus W, DiNardo CD; Birdwell C, Davis JA, Kadia TM, Takahashi K, Short N, Daver N, Ohanian M, et al. Effective therapy for AML with RUNX1 mutation by cotreatment with inhibitors of protein translation and BCL2. Blood 2022; 139(6): 907-921. https://doi.org/10.1182/blood.2021013156 PMid:34601571
     
105. Vergez F, Largeaud L, Bertoli S, Nicolau ML, Riea JB, Vergnolle I, Saland E, Sarry A, Huguet F, et al. Phenotypically-defined stages of leukemia arrest predict main driver mutation subgroups, and outcome in acute myeloid leukemia. Blood Cancer J 2022; 12(9): 117. https://doi.org/10.1038/s41408-022-00712-7 PMid:35973983 PMCid:PMC9381519
     
106. Masarova L, DiNardo CD, Bose P, Pemmaraju N, Daver NG, Kadia TM, Chifotides HT, Zhou L, Borthakur G, Estrov Z, et al. Single-center experience with venetoclax combinations in patients with newly diagnosed and relapsed AML evolving from MPNs. Blood Adv 2021; 5: 2156-2161. https://doi.org/10.1182/bloodadvances.2020003934 PMid:33885751 PMCid:PMC8095138
     
107. Pullarkat V, Pratz K, Dohner H, Recher C, Thirman MJ, DiNardo CD, Fenaux P, Schuh AC, Wei AH, Pigneux A, et al. Venetoclax and azacytidine combination in chemotherapy ineligible untreated patients with therapy-related myeloid neoplasms, antecedent myelodysplastic syndromes, or myelodysplastic/myeloproliferative neoplasms. J Clin Oncol 2021; (suppl. 15): 7011. https://doi.org/10.1200/JCO.2021.39.15_suppl.7011
     
108. Short NJ, Venugopal S, Qiao W, Kadia TM, Ravandi F, Macaron W, Dinardo CD, Daver N, Konopleva M, Borthakur G, et al. Impact of frontline treatment approach on outcomes in patients with secondary AML with prior hypomethylating agent exposure. J Hematol Oncol 2022; 15:12. https://doi.org/10.1186/s13045-022-01229-z PMid:35093134 PMCid:PMC8800349
     
109. Ganan-Gomez I, Yang H, Ma F, Montalban-Bravo G, Thongon N, Marchica V, Richard-Carpentier G, Chien K, Manyam G, Wang F, et al. Stem cell architecture drives myelodysplatic syndrome progression and predicts response to venetoclax-based therapy. Nat Med 2022; 28: 557-567. https://doi.org/10.1038/s41591-022-01696-4 PMid:35241842 PMCid:PMC8938266
     
110. Ball BJ, Famulare CA, Stein EM, Tallman MS, Derkach A, Roshal M, Gill SI, Manning BM, Koprivnikar J, McClaskey J, et al. Venetoclax and hypomethylating agents induce high response rates in MDS, including patients after HMA failure. Blood Adv 2020; 4(13): 2866-2870. https://doi.org/10.1182/bloodadvances.2020001482 PMid:32589727 PMCid:PMC7362378
     
111. Maiti A, Konopleva M. How we incorporate venetoclax in treatment regimens for acute myeloid leukemia. The Cancer Journal 2022; 28: 2-13. https://doi.org/10.1097/PPO.0000000000000567 PMid:35072368 PMCid:PMC8785772
     
112. Lchowiez CA, Atluri H, DiNardo CD. Advancing the standard: venetoclax combined with intensive induction and consolidation therapy for acute myeloid leukemia. Ther Adv Hematol 2022; 13: 1-15. https://doi.org/10.1177/20406207221093964 PMid:35510212 PMCid:PMC9058453
     
113. Diao S, Nichols ED, DiNardo CD, Konopleva M, Ning J, Qiao W, Maiti A, DiPippo AJ. Incidence of tumor lysis syndrome in patients with acute myeloid leukemia undergoing low-intensity induction with venetoclax. Am J Hematol 2021; 96(3): E65-E68. https://doi.org/10.1002/ajh.26060 PMid:33259075
     
114. Arora S, Zainaldin C, Bathini S, Gupta U, Woth S, Bachiashvili R, Godby K, Jamy O, Rangaraju S, Diamond B, et al. Tumor lysis syndrome and infectious complications during treatment with venetoclax combined with azacytidine or decitabine in patients with acute myeloid leukemia. Leuk Res 2011; 117: 106844. https://doi.org/10.1016/j.leukres.2022.106844 PMid:35487134
     
115. Taurino D, Frigeni M, Grassi A, Cavallaro G, Salmoiraghi S, Spinelli O, Rambaldi A, Lussana F. Concurrent diagnosis of acute myeloid leukemia and symptomatic COVID-19 infection: a case report successfully treated with azacytidine-venetoclax combination.Med J Hemat Infect Dis 2021; 13(1): e2021057. https://doi.org/10.4084/MJHID.2021.057 PMid:34527209 PMCid:PMC8425345
     
116. Cristiano A, Palmieri R, Fabiani E, Ottone T, Divona M, Salvi A, Buccisano F, Maurillo L, Tarella C, Arcese W, Voso MT. The venetoclax/azacitidine combination targets the disease clone in acute myeloid leukemia, being effective and safe in a patient with COVID-19. Med J Hemat Infect Dis 2022; 14(1): 2022041. https://doi.org/10.4084/MJHID.2022.041 PMid:35615323 PMCid:PMC9083951
     
117. Agarwal SK, Hu B, Chien D, Wong SL, Salem AH. Evaluation of rifampin's transporter inhibitory and CYP3A4 inductive effects on the pharmacokinetics of venetoclax, a BCL-2 inhibitor: results of a single- and multiple-dose study. J Clin Pharmacol 2016; 56: 1335-1343 https://doi.org/10.1002/jcph.730 PMid:26953185
     
118. Agarwal SK, Salem AH, Danilov AV, Hu B, Puvvada S, Gutierrez M, Chien D, Lewis LD, Wong SL. Effect of ketoconazole, a strong CYP3A4 inhibitor, on the pharmacokinetics of venetoclax, a BCL-2inhibitor, in patients with non-Hodgkin lymphoma. Br J Pharmacol 2016; 83: 846-854. https://doi.org/10.1111/bcp.13175 PMid:27859472 PMCid:PMC5346863
     
119. Liu H, Michmerhuizen MJ, Lao Y, Wan K, Salem AH, Sawicki J, Serby M, Vaidyanathan S, Wong SL, Agarwal S, et al. Metabolism and disposition of a novel B-cell lymphoma-2 inhibitor venetoclax in humans and characterization of its unusual metabolites. Drug Met Disposition 2017; 45: 294-305. https://doi.org/10.1124/dmd.116.071613 PMid:27993930
     
120. Roberts AW, Davids MS, Pagel JM, Kahl BS, Puvvada SD, Gericitano JF, Kipps TJ, Anderson MA, Brown JR, Gressick L, et al. Targeting BCL2 with venetoclax in relapsed chronic lymphocytic leukemia. N Engl J Med 2016; 374: 311-322. https://doi.org/10.1056/NEJMoa1513257 PMid:26639348 PMCid:PMC7107002
     
121. Salem AH, Agarwal SK, Dunbar M, Enschede SHL, Humerickhouse RA, Wong SL. Pharmacokinetics of venetoclax, a novel BCL-2 inhibitor, in patients with relapsed or refractory chronic lymphocytic leukemia or non-Hodgkin's lymphoma. J Clin Pharmacol 2017; 57: 484-492. https://doi.org/10.1002/jcph.821 PMid:27558232
     
122. Agarwal SK, DiNardo CD, Potluri J, Dunbar M, Kantarjian HM, Humerickhouse RA, Wong SL, Menon RM, Konopleva M and Salem AH. Management of venetoclax-posaconazole interaction in acute myeloid patients: evaluation of dose adjustments. Clin Ther 2017; 39: 359-367. https://doi.org/10.1016/j.clinthera.2017.01.003 PMid:28161120
     
123. Bhatnagar S, Mukherjee D, Salem AH, Miles D, Menon RM, Gibbs JP. Dose adjustment of venetoclax when co-administered with Posaconazole: clinical drug-drug interaction predictions using a PBPK approach. Cancer Chemother Pharmacol 2021; 87: 465-474. https://doi.org/10.1007/s00280-020-04179-w PMid:33398386
     
124. Rausch CR, DiNardo C, Maiti A, Jammal N, Kadia TM, Marx K, Borthakur GK, Savoy M, Pemmaraju N, Marx K, et al. Venetoclax dosing in combination with antifungal agents: real world experience in patients with acute myeloid leukemia. Blood 2019; 134 (suppl.1): 2640. https://doi.org/10.1182/blood-2019-131988
     
125. Rausch CR, DiNardo C, Maiti A, Jammal N, Kadia TM, Marx K, Borthakur GK, Savoy M, Pemmaraju N, Marx K, et al. Duration of cytopenias with concomitant venetoclax and azole antifungals in acute myeloid leukemia. Cancer 2021; 127: 2489-2499 https://doi.org/10.1002/cncr.33508 PMid:33793970 PMCid:PMC8249340
     
126. Eisenmann ED, Garrison DA, Talebi Z, Jin Y, Silvaroli JA, Kim JG, Sparreboom A, Savona MR, Mims AS and Baker SD. Interaction of antifungal drugs with CYP3A- and OATP1B-mediated venetoclax elimination. Pharmaceutics 2022; 14: 694. https://doi.org/10.3390/pharmaceutics14040694 PMid:35456528 PMCid:PMC9025810
     
127. Ong F, Kim K, Konopleva MY. Venetoclax resistance: mechanistic insights and future strategies. Cancer Drug Resistance 2022; 5: 380-400. https://doi.org/10.20517/cdr.2021.125 PMid:35800373 PMCid:PMC9255248
     
128. Bhatt S, Pioso MS, Olesinski EA, Yilma B, Ryan JA, Mashaka T, Leutz B, Adamia S, Zhu H, Kuang Y, et al. Reduced mitochondrial apoptotic priming drives resistance to BH3 mimetics in acute myeloid leukemia. Cancer Cell 2020; 38: 872-890. https://doi.org/10.1016/j.ccell.2020.10.010 PMid:33217342 PMCid:PMC7988687
     
129. Pan R, Ruvolo VR, Wei J, Konopleva M, Reed JC, Pellecchia M, Andreef M, Ruvolo PP. Inhibition of Mcl-1 with the pan-Bcl-2 family inhibitor (-)BI97D6 overcomes ABT-737 resistance in acute myeloid cells. Blood 2015; 126(3): 363-372. https://doi.org/10.1182/blood-2014-10-604975 PMid:26045609 PMCid:PMC4504949
     
130. Lin KH, Winter PS, Xie A, Roth C, Martz CA, Stein EM, Anderson GR, Tingley JP, Wood KC. Targeting MCL-1/BCL-XL forestalls the acquisition of resistance to ABT-199 in acute myeloid leukemia. Sci Rep 2016; 6: 27696. https://doi.org/10.1038/srep27696 PMid:27283158 PMCid:PMC4901329
     
131. Ewald L, Dittmann J, Vogler M, Fulda S. Side-by-side comparison of BH3-mimetics identifies MCL-1 as a key therapeutic target in AML. Cell Death Dis 2019; 10(12): 917. https://doi.org/10.1038/s41419-019-2156-2 PMid:31801941 PMCid:PMC6892884
     
132. Hormi M, Birsen R, Belhadj M, Huynh T, Aquilar LC, Grignano E, Hallaoui L, Guilloneau F, Mayeux P, Hunault M, et al. Pairing MCL-1 inhibition with venetoclax improves therapeutic efficiency of BH3-mimetics in AML. Eur J Haematol 2020; 105(5): 588-596. https://doi.org/10.1111/ejh.13492 PMid:32659848
     
133. Ramsey HE, Fischer MA, Lee T, Gorska AE, Arrate MP, Fuller L, Boyd KL, Strickland SA, Sensitaffar J, Hoghdal LJ, et al. A novel MCL1 inhibitor combined with venetoclax rescues venetoclax-resistant acute myelogenous leukemia. Cancer Discover 2018; 8(12): 156-1581. https://doi.org/10.1158/2159-8290.CD-18-0140 PMid:30185627 PMCid:PMC6279595
     
134. Moujalled D, Pomilio G, Chiurau C, Ivey A, Salmon J, Rijal S, Macraild S, Zhang L, The TC, Tong JS, et al. Combining BH3-mimetics to target both BCL-2 and MCL-1 has potent activity in pre-clinical models of acute myeloid leukemia. Leukemia 2019; 33(4): 905-917. https://doi.org/10.1038/s41375-018-0261-3 PMid:30214012 PMCid:PMC6484700
     
135. Carter BZ, Mak PY, Tag W, Zhang Q, Ruvolo V, Kuruvilla VM, Wang X, Max DH, Battula VL, Konopleva M, eal. Maximal activation of apoptosis signaling by cotargeting antiapoptotic proteins in BH3 mimetic-resistant AML and AML stem cells. Mol Cancer Ther 2022; 21(6): 879-889. https://doi.org/10.1158/1535-7163.MCT-21-0690 PMid:35364607
     
136. Liu F, Zhao Q, Su Y, Lv J, Gai Y, Liu S, Liu H, Wang Y, Wang G. Cotargeting of Bcl-2 and Mcl-1 shows promising antileukemic activity against AML cells including those with acquired cytarabine resistance. Exp Hematol 2022; in press. https://doi.org/10.1016/j.exphem.2021.10.006 PMid:34767916
     
137. Weller S, Toennieben A, Schaefer B, Beigl T, Muenchow A, Bopple K, Hofmann U, Gillissen B, Aulitzky WE, Kopp HG, et al. The BCL-2 inhibitor ABT-199/venetoclax synergizes with proteasome inhibition via transactivation of the MCL-1 antagonis NOXA. Cell Daeth Discov 2022; 8(1): 215. https://doi.org/10.1038/s41420-022-01009-1 PMid:35443750 PMCid:PMC9021261
     
138. Zhang H, Nakauchi Y, Kohnke T, Stafford M, Bottomly D, Thomas R, Wilmot B, McWeeney SK, Majeti R, Tyner JM. Integrated analysis of patients samples identifies biomarkers for venetoclax efficacy and combination strategies in acute myeloid leukemia. Nat Cancer 2020; 1(8): 826-839. https://doi.org/10.1038/s43018-020-0103-x PMid:33123685 PMCid:PMC7591155
     
139. Pan R, Ruvolo V, Um H, Leverson JD, Nichols G, Reed JC, Konopleva M, Andreef M. Synthetic lethality of combined Bcl-2 inhibition and p53 activation in AML: mechanisms and superior antileukemic efficacy. Cancer Cell 2017; 32: 748-760. https://doi.org/10.1016/j.ccell.2017.11.003 PMid:29232553 PMCid:PMC5730338
     
140. Zhang Q, Riley-Gillis B, Han L, Jia Y, Lodi A, Zhang H, Ganesan S, Pan R, Konoplev SN, Sweeney SR, et al. Activation of RAS/MAPK pathway confers MCL-1 mediated acquired resistance to BCL-2 inhibitor venetoclax in acute myeloid leukemia. Signal Transd Targeted Therapy 2022; 7: 51. https://doi.org/10.1038/s41392-021-00870-3 PMid:35185150 PMCid:PMC8858957
     
141. Stevens BM, Joenes CI, Winters A, Dugan J, Abbott D, Savona MR, Fesik SW, Pollyea DA, Jordan CT. PTPN11 mutations confer unique metabolic properties and increase resistance to venetoclax and azacytidine in acue myelogenous leukemia. Blood 2018; 132: 909. https://doi.org/10.1182/blood-2018-99-119806
     
142. Gemans BF, Zwaan CM, Martinelli S, Harrell P, de Lange D, Carca C, Reinhardt D, Hahlen K, Creutzig U, Tartaglia M, et al. Differences in the prevalence of pTPN11 mutations in FABM5 pediatric acute myeloid leukemia. Br J Haematol 2005; 130: 800-801. https://doi.org/10.1111/j.1365-2141.2005.05685.x PMid:16115145
     
143. Pei S, Pollyea DA; GustafsonA, Stevens BM, Minhajuddin M, Fu R, Riemondy KA, Gillen AE, Sheridan RM, Kim J, et al. Monocytic subclones confer resistance to venetoclax-based therapy in patients with acute myeloid leukemia. Cancer Discov 2020; 10: 536-551 https://doi.org/10.1158/2159-8290.CD-19-0710 PMid:31974170 PMCid:PMC7124979
     
144. Han L, Zhang Q, Dail M, Shi C, Cavazos A, Ruvolo VR, Zhao Y, Kim E, Rahmani M, Mak DC, et al. Concomitant targeting of BCL2 with venetoclax and MAPK signaling with cobimetinib in acute myeloid leukemia models. Haematologica 2020; 105(3): 697-707. https://doi.org/10.3324/haematol.2018.205534 PMid:31123034 PMCid:PMC7049339
     
145. Pullarkat VA, Lacayo NI, Jabbour E, Rubnitz JE, Bajel A, Laetsch TW, Leonard J, Colace SI, Khaw SL, Fleming KA, et al. Ventoclax and navitoclax in combination with chemotherapy in patients with relapsed or refractory acute lymphoblastic leukemia and lymphoblastic lymphoma. Cancer Discovery 2021; 1(6): 1440-1453. https://doi.org/10.1158/2159-8290.CD-20-1465 PMid:33593877 PMCid:PMC9533326