A dynamic 3-factor survival model for acute myeloid leukemia that accounts for response to induction chemotherapy

Literature review and expert opinion on the treatment of high-risk acute myeloid leukemia in patients who are eligible for intensive chemotherapy

In patients with Acute Myeloid Leukemia (AML), the assessment of disease risk plays a central role in the era of personalized medicine. Indeed, integrating baseline clinical and biological features on a case-by-case basis is not only essential to select which treatment would likely result in a higher probability of achieving complete remission, but also to dynamically customize any subsequent therapeutic intervention. For young high-risk patients with low comorbidities burden and in good general conditions (also called "fit" patients), intensive chemotherapy followed by allogeneic stem cell transplantation still represents the backbone of any therapeutic program. However, with the approval of novel promising agents in both the induction/consolidation and the maintenance setting, the algorithms for the management of AML patients considered eligible for intensive chemotherapy are in constant evolution. In this view, we selected burning issues regarding the identification and management of high-risk AML, aiming to provide practical advice to facilitate their daily clinical management in patients considered eligible for intensive chemotherapy.

Venetoclax and hypomethylating agent combination therapy in newly diagnosed acute myeloid leukemia: Genotype signatures for response and survival among 301 consecutive patients

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

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.

Should patients with acute myeloid leukemia treated with venetoclax-based regimens receive antifungal prophylaxis?

Invasive fungal disease (IFD) is a major complication in patients with acute myeloid leukemia (AML) receiving intensive induction chemotherapy, and the use of anti-mold prophylaxis is considered standard of care. On the other hand, the use of anti-mold prophylaxis in AML patients receiving less-intensive venetoclax-based regimens is not well established, basically because the incidence of IFD may not be high enough to justify primary antifungal prophylaxis. Furthermore, dose adjustments in venetoclax are needed because of drug interactions with azoles. Finally, the use of azoles is associated with toxicity, including liver, gastrointestinal and cardiac (QT prolongation) toxicity. In a setting of low incidence of invasive fungal disease, the number needed to harm would be higher than the number needed to treat. In this paper we review the risk factors for IFD in AML patients receiving intensive chemotherapeutic regimens, the incidence and risk factors for IFD in patients receiving hypomethylating agents alone, and in patients receiving less-intensive venetoclax-based regimens. We also discuss potential problems with the concomitant use of azoles, and present our perspective on how to manage AML patients receiving venetoclax-based regimens without primary antifungal prophylaxis.

Prediction of survival with lower intensity therapy among older patients with acute myeloid leukemia

BACKGROUND

The aim of this study was to develop a prognostic model for survival in older/unfit patients with newly diagnosed acute myeloid leukemia (AML) who were treated with lower-intensity chemotherapy regimens.

METHODS

The authors reviewed all older/unfit patients with newly diagnosed AML who received lower-intensity chemotherapy from 2000 until 2020 at their institution. A total of 1462 patients were included. They were divided (3:1 basis) into a training (n = 1088) and a validation group (n = 374).

RESULTS

In the training cohort of 1088 patients (median age, 72 years), the multivariate analysis identified 11 consistent independent adverse factors associated with survival: older age, therapy-related myeloid neoplasm, existence of previous myelodysplastic syndrome or myeloproliferative neoplasms, poor performance status, pulmonary comorbidity, anemia, thrombocytopenia, elevated lactate dehydrogenase, cytogenetic abnormalities, and the presence of infection at diagnosis, and therapy not containing venetoclax. The 3-year survival rates were 52%, 24%, 10%, and 1% in favorable, intermediate, poor, and very poor risk, respectively. This survival model was validated in an independent cohort. In a subset of patients in whom molecular mutation profiles were performed in more recent times, adding the mutation profiles after accounting for the effects of previous factors identified IDH2 (favorable), NPM1 (favorable), and TP53 (unfavorable) mutations as molecular prognostic factors.

CONCLUSION

The proposed survival model with lower-intensity chemotherapy in older/unfit patients with newly diagnosed AML may help to advise patients on their expected outcome, to propose different strategies in first complete remission, and to compare the results of different existing or future investigational therapies.

PLAIN LANGUAGE SUMMARY

Lower intensity therapy can be considered for older patients to avoid severe toxicities and adverse events. However, survival prediction in AML was commonly developed in patients who received intensive chemotherapy. In this study, we have proposed a survival model to guide therapeutic approach in older patients who received lower-intensity therapy.

Therapeutic Advances in Immunotherapies for Hematological Malignancies

Following the success of immunotherapies such as chimeric antigen receptor transgenic T-cell (CAR-T) therapy, bispecific T-cell engager therapy, and immune checkpoint inhibitors in the treatment of hematologic malignancies, further studies are underway to improve the efficacy of these immunotherapies and to reduce the complications associated with their use in combination with other immune checkpoint inhibitors and conventional chemotherapy. Studies of novel therapeutic strategies such as bispecific (tandem or dual) CAR-T, bispecific killer cell engager, trispecific killer cell engager, and dual affinity retargeting therapies are also underway. Because of these studies and the discovery of novel immunotherapeutic target molecules, the use of immunotherapy for diseases initially thought to be less promising to treat with this treatment method, such as acute myeloid leukemia and T-cell hematologic tumors, has become a reality. Thus, in this coming era of new transplantation- and chemotherapy-free treatment strategies, it is imperative for both scientists and clinicians to understand the molecular immunity of hematologic malignancies. In this review, we focus on the remarkable development of immunotherapies that could change the prognosis of hematologic diseases. We also review the molecular mechanisms, development processes, clinical efficacies, and problems of new agents.