Allogeneic hematopoietic cell transplantation for acute myeloid leukemia in first complete remission after 5-azacitidine and venetoclax: a multicenter retrospective study

Venetoclax-based treatment in acute myeloid leukemia: an unexpected bonus on the path to allogeneic hematopoietic stem cell transplant?

Despite the approval of new drugs, the inclusion of -omics-derived data and the integration of machine learning in both the diagnostic and therapeutic process, the prognosis of acute myeloid leukemia (AML) remains dismal. The curative path is still aimed at achieving a successful allogeneic hematopoietic stem cell transplant (HSCT) in most patients. Nevertheless, access to this procedure is limited to eligible patients. Moreover, post-HSCT outcomes are influenced by AML heterogeneity and patient-related factors. The rise of venetoclax (VEN)-based combinations as standard of care in the treatment of older or unfit AML patients, together with their peculiar management profile, has led researchers to evaluate the feasibility of this approach in patients proceeding toward HSCT. We reviewed the available evidence to weigh up the advantages and pitfalls of this new therapeutic strategy.

Molecular ontogeny underlies the benefit of adding venetoclax to hypomethylating agents in newly diagnosed AML patients

The clinical impact of molecular ontogeny in acute myeloid leukemia (AML) was defined in patients treated with intensive chemotherapy. In a cohort of 314 newly diagnosed AML patients, we evaluated whether molecular ontogeny subgroups have differential benefit of venetoclax (VEN) added to hypomethylating agents (HMA). In secondary ontogeny (n = 115), median overall survival (OS)(14.1 vs. 6.9 months, P = 0.0054), composite complete remission (cCR 61% vs. 18%, P < 0.001) and allogeneic hematopoietic stem cell transplant (alloHCT) (24% vs. 6%, P = 0.02) rates were better in patients treated with HMA + VEN vs. HMA. In contrast, in TP53 AML(n = 111) median OS (5.7 vs. 6.1, P = 0.93), cCR (33% vs. 37%, P = 0.82) and alloHCT rates (15% vs. 8%, P = 0.38) did not differ between HMA + VEN vs. HMA. The benefit of VEN addition in the secondary group was preserved after adjustment for significant clinicopathologic variables (HR 0.59 [95% CI 0.38-0.94], P = 0.025). The OS benefit of HMA + VEN in secondary ontogeny was similar in those with vs. without splicing mutations (P = 0.92). Secondary ontogeny AML highlights a group of patients whose disease is selectively responsive to VEN added to HMA and that the addition of VEN has no clinical benefit in TP53-mutated AML.

Strategies to reduce relapse risk in patients undergoing allogeneic stem cell transplantation for acute myeloid leukaemia

Allogeneic stem cell transplantation is a centrally important curative strategy in adults with acute myeloid leukaemia; however, relapse occurs in a significant proportion of patients and remains the leading cause of treatment failure. The prognosis for patients who relapse post-transplant remains poor, and the development of new strategies with the ability to reduce disease recurrence without increasing transplant toxicity remains a priority. In this review, within the context of our understanding of disease biology and the graft-versus-leukaemia (GVL) effect, we will discuss established, evolving and novel approaches for increasing remission rates, decreasing measurable residual disease pretransplant, future methods to augment the GVL effect and the opportunities for post-transplant maintenance. Future progress depends upon the development of innovative trials and networks, which will ensure the rapid assessment of emerging therapies in prospective clinical trials.

Hypomethylating agents plus venetoclax compared with intensive induction chemotherapy regimens in molecularly defined secondary AML

Molecularly defined secondary acute myeloid leukemia is associated with a prior myeloid neoplasm and confers a worse prognosis. We compared outcomes of molecularly defined secondary AML patients (n = 395) treated with daunorubicin and cytarabine (7 + 3, n = 167), liposomal daunorubicin and cytarabine (CPX-351, n = 66) or hypomethylating agents (HMA) + venetoclax (VEN) (n = 162). Median overall survival (OS) was comparable between treatment groups among patients aged >60 years. In a multivariable model HMA + VEN vs. 7 + 3 was associated with better OS (hazard ratio [HR] 0.64 [95% confidence interval (CI) 0.42-0.98, p = 0.041]), whereas CPX-351 vs. 7 + 3 was not (HR 0.79 [CI 95% 0.50-1.25, p = 0.31]). Allogeneic hematopoietic stem cell transplantation, BCOR and IDH mutations were associated with improved OS; older age, prior myeloid disease, NRAS/KRAS mutations, EZH2 mutation, and monosomal karyotype were associated with worse OS. When analyzed in each treatment separately, the IDH co-mutations benefit was seen with 7 + 3 and the detrimental effect of NRAS/KRAS co-mutations with HMA + VEN and CPX-351. In pairwise comparisons adjusted for age, HMA + VEN was associated with improved OS vs. 7 + 3 in patients with SF3B1 mutation and improved OS vs. CPX-351 in those with RNA splicing factor mutations. In molecularly defined secondary AML treatment with HMA + VEN might be preferred but could further be guided by co-mutations.

A Markov analysis of azacitidine and venetoclax vs induction chemotherapy for medically fit patients with AML

ABSTRACT

Although induction chemotherapy (IC) is the standard of care in medically fit patients with newly diagnosed acute myeloid leukemia (AML), limited retrospective data indicate that patients at adverse-risk may benefit from azacytidine and venetoclax (aza-ven). Our goal was to perform a Markov decision analysis to determine whether IC or aza-ven is the optimal induction regimen in this population. Using the TreeAge software, Markov models were created for adverse-risk and intermediate-risk cohorts. A systematic review of the literature informed the transition probabilities and utilities included in the analyses. Our primary outcome was quality-adjusted life years (QALYs) gained over 5 years after diagnosis. Overall, patients at adverse risk treated with IC gained 1.4 QALYs, compared with 2.0 QALYs in patients treated with aza-ven. Patients at adverse risk treated with IC and allogeneic stem cell transplantation (allo-SCT), IC, aza-ven and allo-SCT, or aza-ven gained 2.1, 1.5, 3.0, and 1.9 QALYs, respectively. Meanwhile, patients at intermediate risk treated with IC gained 2.0 QALY, compared with 1.7 QALY in patients treated with aza-ven. Patients at intermediate risk treated with IC and allo-SCT, IC, aza-ven and allo-SCT, and aza-ven gained 2.7, 2.3, 2.6, and 1.8 QALYs, respectively. We have demonstrated that medically fit patients with newly diagnosed adverse-risk AML may benefit from treatment with aza-ven over those treated with IC, whereas IC remains the preferred approach for patients at intermediate risk. Our work challenges the use of the European LeukemiaNet risk classification for patients treated with aza-ven and highlights the need for prospective investigation into aza-ven as induction therapy for medically fit patients.

The approach of HMA plus VEN with or without BMT for all patients with AML

Treatment options for acute myeloid leukemia (AML) have expanded over the last 5 years. New regimens are increasing the options for patients who previously may not have been offered any antineoplastic therapy. The use of the hypomethylating agent (HMA) decitabine or azacitidine combined with the BCL2 inhibitor venetoclax (HMA-VEN) has improved overall survival in an older and unfit population compared to HMA therapy alone. Delivering these regimens outside academic centers allows more patients with AML to be treated, though support and collaboration with allogeneic stem cell transplant (SCT) centers should still be considered to determine eligibility and promptly initiate a donor search for potential transplant candidates. Expanding the use of HMA-VEN to younger and fit patients who are also candidates for intensive chemotherapy (IC) is being studied prospectively and is not recommended at this time outside of a clinical trial. Retrospective studies suggest populations that may benefit from HMA-VEN over IC, but this is not yet confirmed prospectively. Utilizing HMA-VEN prior to allogeneic SCT is also under investigation, and some retrospective data show feasibility and the ability to achieve measurable residual disease negativity pretransplant. Upcoming prospective randomized clinical trials aim to answer the comparability or superiority of HMA-VEN vs IC in fit populations and its potential use as a standard pretransplant induction regimen.

Impact of type of induction therapy on outcomes in older adults with AML after allogeneic stem cell transplantation

Although venetoclax-based lower-intensity regimens have greatly improved outcomes for older adults with acute myeloid leukemia (AML) who are unfit for intensive chemotherapy, the optimal induction for older patients with newly diagnosed AML who are suitable candidates for hematopoietic stem cell transplant (HSCT) is controversial. We retrospectively analyzed the post HSCT outcomes of 127 patients ≥60 years of age who received induction therapy at our institution with intensive chemotherapy (IC; n = 44), lower-intensity therapy (LIT) without venetoclax (n = 29), or LIT with venetoclax (n = 54) and who underwent allogeneic HSCT in the first remission. The 2-year relapse-free survival (RFS) was 60% with LIT with venetoclax vs 54% with IC, and 41% with LIT without venetoclax; the 2-year overall survival (OS) was 72% LIT with venetoclax vs 58% with IC, and 41% with LIT without venetoclax. The benefit of LIT with venetoclax induction was greatest in patients with adverse-risk AML (2-year OS: 74%, 46%, and 29%, respectively). Induction with LIT, with or without venetoclax, was associated with the lowest rate of nonrelapse mortality (NRM) (2-year NRM: 17% vs 27% with IC; P = .04). Using multivariate analysis, the type of induction therapy did not significantly affect any of the post HSCT outcomes evaluated; hematopoietic cell transplantation-specific comorbidity index was the only factor that independently predicted RFS and OS. LIT plus venetoclax followed by HSCT is a feasible treatment strategy in older, fit, HSCT-eligible patients with newly diagnosed AML and may be particularly beneficial for those with adverse-risk disease.

Clinical status of induction therapy incorporating a hypomethylating agent for newly diagnosed adult acute myeloid leukemia compared to the standard 7+3 regimen

INTRODUCTION

Cytarabine and anthracycline combination therapy (7 + 3 regimen) is the standard care for induction chemotherapy in adult patients with acute myeloid leukemia (AML). Although this intensive regimen achieves a high response rate, it is highly toxic, especially in elderly or frail patients. Hypomethylating agents approved initially for high-risk myelodysplastic syndrome had longer survival times than conventional care in elderly patients with newly diagnosed AML.

AREAS COVERED

We summarize the latest information regarding induction therapy using hypomethylating agents (azacitidine and decitabine) for newly diagnosed AML.

EXPERT OPINION

For untreated patients ineligible for an intensive regimen, a phase III trial exhibited the survival benefit of adding the highly selective BCL2 inhibitor venetoclax to azacitidine. The National Comprehensive Cancer Network guidelines recommend azacitidine or decitabine plus venetoclax as an option for patients with poor-risk AML, including those with TP53 mutations and AML with the cytogenetic features of myelodysplastic syndrome. Future studies should evaluate positioning this combination as an induction therapy for younger patients eligible for hematopoietic stem cell transplantation. Without randomized trials, propensity score matching analysis suggested a comparable prognosis between azacitidine combination and intensive chemotherapy. Considering the feasibility of a doublet regimen incorporating azacitidine, a triplet regimen should be examined.

Hypomethylating agent-based therapies in older adults with acute myeloid leukemia - A joint review by the Young International Society of Geriatric Oncology and European Society for Blood and Marrow Transplantation Trainee Committee

Acute myeloid leukemia (AML) is associated with poor outcomes in older adults. A major goal of treatment is to balance quality of life and functional independence with disease control. With the approval of new, more tolerable regimens, more older adults are able to receive AML-directed therapy. Among these options are hypomethylating agents (HMAs), specifically azacitidine and decitabine. HMAs have become an integral part of AML therapy over the last two decades. These agents are used either as monotherapy or nowadays more commonly in combination with other agents such as the Bcl-2 inhibitor venetoclax. Biological AML characteristics, such as molecular and cytogenetic risk factors, play crucial roles in guiding treatment decisions. In patients with high-risk AML, HMAs are increasingly used rather than intensive chemotherapy, although further trials based on a risk-adapted approach using patient- and disease-related factors are needed. Here, we review trials and evidence for the use of HMA monotherapy and combination therapy in the management of older adults with AML. Furthermore, we discuss the use of HMAs and HMA combination therapies in AML, mechanisms of action, their incorporation into hematopoietic stem cell transplantation strategies, and their use in patients with comorbidities and reduced organ function.

A Successful Bridge Therapy Combining Hypomethylating Agents with Venetoclax for Adult Patients with Newly Diagnosed or Relapsed/Refractory Acute Myeloid Leukemia

Recently, the combination of VEN-HMA has been shown to achieve durable responses in patients with both newly diagnosed (ND) and R/R-AML. We retrospectively evaluated the post-allo-HCT outcomes of 50 patients who received VEN-HMA therapy. In total, 10 were ND and 40 were R/R and, at the time of HCT, the median age was 53 years. In the ND- and R/R-AML groups, the percentage of patients who achieved CR/CRi or MLFS was 90% and 92.5%, respectively. In all, after a median follow-up of 13.7 months, the probabilities of overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM) at 1 year were 63.7%, 59.3%, 28.5%, and 12.2%, respectively. In addition, the cumulative incidences of grade II–IV acute graft-versus-host disease (GVHD) and moderate–severe chronic GVHD at 1 year were 28.4% and 37.4%, respectively. In multivariate analysis, the factors associated with a statistically significant impact on OS were VEN-HMA cycle (p = 0.021), ELN risk group (p = 0.041), and the response to VEN-HMA therapy before allo-HCT (p = 0.003). Although 80% of our patients had R/R-AML and 30% underwent a second allo-HCT, our data still suggest that allo-HCT following VEN-HMA therapy is a safe and effective treatment option.

Acute myeloid leukemia: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Acute myeloid leukemia (AML) is a frequently fatal bone marrow stem cell cancer characterized by unbridled proliferation of malignant marrow stem cells with associated infection, anemia, and bleeding. An improved understanding of pathophysiology, improvements in measurement technology and at least 10 recently approved therapies have led to revamping the diagnostic, prognostic, and therapeutic landscape of AML.

DIAGNOSIS

One updated and one new classification system were published in 2022, both emphasizing the integration of molecular analysis into daily practice. Differences between the International Consensus Classification and major revisions from the previous 2016 WHO system provide both challenges and opportunities for care and clinical research.

RISK ASSESSMENT AND MONITORING

The European Leukemia Net 2022 risk classification integrates knowledge from novel molecular findings and recent trial results, as well as emphasizing dynamic risk based on serial measurable residual disease assessment. However, how to leverage our burgeoning ability to measure a small number of potentially malignant myeloid cells into therapeutic decision making is controversial.

RISK ADAPTED THERAPY

The diagnostic and therapeutic complexity plus the availability of newly approved agents requires a nuanced therapeutic algorithm which should integrate patient goals of care, comorbidities, and disease characteristics including the specific mutational profile of the patient's AML. The framework we suggest only represents the beginning of the discussion.

Update on current treatments for adult acute myeloid leukemia: to treat acute myeloid leukemia intensively or non-intensively? That is the question

For several decades, the treatment for acute myeloid leukemia (AML) has been a dichotomous choice between intensive chemotherapy strategies with curative intent and non-intensive options including supportive care. Patients' age and fitness, as well as comorbidities, primarily influenced this choice. However, the therapeutic armamentarium is evolving, so that there are highly effective and increasingly specific drugs, fitting the mutational profile of a patient's leukemia. There is now a spectrum of treatment options that are less intense and can be administered in an outpatient setting and to a substantial extent are equally or even more effective than standard intensive therapy. We are, therefore, witnessing a radical change in the treatment landscape of AML. In this review, we examine the current treatment options for patients with AML, considering the molecular spectrum of the disease on the background of patient-related factors.

New drugs before, during, and after hematopoietic stem cell transplantation for patients with acute myeloid leukemia

The treatment of acute myeloid leukemia (AML) has evolved over the past few years with the advent of next-generation sequencing. Targeted therapies alone or in combination with low-dose or high-intensity chemotherapy have improved the outcome of patients with AML treated in the frontline and relapsed/refractory settings. Despite these advances, allogeneic stem cell transplantation (allo-HCT) remains essential as consolidation therapy following frontline treatment in intermediate-and adverse-risk and relapsed/refractory disease. However, many patients relapse, with limited treatment options, hence the need for post-transplant strategies to mitigate relapse risk. Maintenance therapy following allo-HCT was developed for this specific purpose and can exploit either a direct anti-leukemia effect and/or enhance the bona fide graft-versus-leukemia effect without increasing the risk of graft-versus-host disease. In this paper, we summarize novel therapies for AML before, during, and after allo-HCT and review ongoing studies.

Comparison of haploidentical hematopoietic stem cell transplantation with chemotherapy in older adults with acute myeloid leukemia

Acute myeloid leukemia (AML) outcomes are very poor in older patients. Haploidentical stem cell transplantation (haplo-SCT) helps to achieve long-term survival. However, the benefit of haplo-SCT versus chemotherapy is unclear in older adults with AML. Outcomes were retrospectively compared among patients aged 55‒65 years for chemotherapy consolidation or haplo-SCT for AML in the first complete remission with intermediate to high-risk disease. Forty-six patients who underwent chemotherapy and 38 patients who underwent haplo-SCT were evaluated in the final analysis. Compared with the chemotherapy group, patients in the haplo-SCT group had significantly better overall survival (OS) (74.0% versus 23.9% at 36 months, p = 0.005) and leukemia-free survival (LFS) (74.0% versus 21.6%, p < 0.001). The cumulative incidence of relapse (CIR) was significantly lower in the haplo-SCT group (17.3% versus 75.4%, p < 0.001). Treatment-related mortality (TRM) was similar in the haplo-SCT and chemotherapy groups (7.9% versus 4.8%, p = 0.587). In the multivariate analysis, haplo-SCT was associated with improved OS, LFS, and decreased CIR. Haplo-SCT did not affect TRM. In conclusion, our data suggest that haploidentical transplant may be an alternative to consolidation chemotherapy as post-remission therapy in patients with intermediate or high-risk AML aged 55‒65 years. Further well-designed studies are needed to validate this result.