Outcomes with lower intensity therapy in TP53-mutated acute myeloid leukemia

Therapy-Related Myeloid Neoplasm: Biology and Mechanistic Aspects of Malignant Progression

Therapy-related myeloid neoplasms (t-MN) arise after a documented history of chemo/radiotherapy as treatment for an unrelated condition and account for 10-20% of myelodysplastic syndromes and acute myeloid leukemia. T-MN are characterized by a specific genetic signature, aggressive features and dismal prognosis. The nomenclature and the subsets of these conditions have changed frequently over time, and despite the fact that, in the last classification, they lost their autonomous entity status and became disease qualifiers, the recognition of this feature remains of major importance. Furthermore, in recent years, extensive studies focusing on clonal hematopoiesis and germline variants shed light on the mechanisms of positive pressure underpinning the rise of driver gene mutations in t-MN. In this manuscript, we aim to review the evolution of defining criteria and characteristics of t-MN from a clinical and biological perspective, the advances in mechanistic aspects of malignant progression and the challenges in prevention and management.

Unmet Horizons: Assessing the Challenges in the Treatment of TP53-Mutated Acute Myeloid Leukemia

Acute myeloid leukemia (AML) remains a challenging hematologic malignancy. The presence of TP53 mutations in AML poses a therapeutic challenge, considering that standard treatments face significant setbacks in achieving meaningful responses. There is a pressing need for the development of innovative treatment modalities to overcome resistance to conventional treatments attributable to the unique biology of TP53-mutated (TP53mut) AML. This review underscores the role of TP53 mutations in AML, examines the current landscape of treatment options, and highlights novel therapeutic approaches, including targeted therapies, combination regimens, and emerging immunotherapies, as well as agents being explored in preclinical studies according to their potential to address the unique hurdles posed by TP53mut AML.

TP53 in AML and MDS: The new (old) kid on the block

MDS and AML are clonal hematopoietic stem cell disorders of increasing incidence, having a variable prognosis based, among others, on co-occurring molecular abnormalities. TP53 mutations are frequently detected in these myeloid neoplasms and portend a poor prognosis with known therapeutic resistance. This article provides a timely review of the complexity of TP53 alterations, providing updates in diagnosis and prognosis based on new 2022 International Consensus Classification (ICC) and World Health Organization (WHO) guidelines. The article addresses optimal testing strategies and reviews current and arising therapeutic approaches. While the treatment landscape for this molecular subgroup is under active development, further exploration is needed to optimize the care of this group of patients with unmet needs.

Single-center phase 2 study of PD-1 inhibitor combined with DNA hypomethylation agent + CAG regimen in patients with relapsed/refractory acute myeloid leukemia

Anti-PD-1 monotherapy had limited clinical efficacy in relapsed/refractory (r/r) AML patients with higher PD-1 and PD-L1 expression. Hence, we investigated the efficacy and safety of PD-1 inhibitor with DNA hypomethylating agent (HMA) + CAG regimen in patients who had failed prior AML therapy. In this phase 2, single-arm study, r/r AML patients received azacitidine or decitabine plus CAG regimen with tislelizumab. Primary endpoints were efficacy (objective response rate [ORR]) and safety. Secondary endpoints included overall survival (OS), event-free survival (EFS) and duration of response (DOR). Statistical analyses were performed using Stata 14.0 and SPSS 20.0 software where P < 0.05 denoted significance. Twenty-seven patients were enrolled patients and completed 1 cycle, and 14 (51.9%) and 4 (14.8%) patients completed 2 and 3 cycles, respectively. ORR was 63% (14: complete remission [CR]/CR with incomplete hematologic recovery [CRi], 3: partial remission (PR), 10: no response [NR]). Median OS (mOS) and EFS were 9.7 and 9.2 months, respectively. With a median follow-up of 8.2 months (1.1-26.9), the mOS was not reached in responders (CR/CRi/PR) while it was 2.4 months (0.0-5.4) in nonresponders (P = 0.002). Grade 2-3 immune-related adverse events (irAEs) were observed in 4 (14.8%) patients and 3 nonresponders died of lung infection after treatment. Tislelizumab + HMA + CAG regimen showed improved outcomes in r/r AML patients with lower pretherapy leukemia burden. irAEs were mild and low-grade and higher pretherapy bone marrow CD4⁺ CD127⁺ PD-1⁺ T cells might serve as a predictor of treatment response.ClinicalTrials.gov identifier NCT04541277.

Optimizing outcomes in secondary AML

Acute myeloid leukemia (AML) secondary to antecedent hematologic disorder or prior therapeutics for cancer represent a diverse group of leukemias often associated with inferior outcomes. Conventional therapy with cytarabine-based chemotherapy has been the mainstay of care for the past 30 years with disappointing overall outcomes. Novel therapies, including liposomal cytarabine/daunorubicin, and venetoclax-based therapies have emerged as options in recent years based on studies showing improvement in outcomes over standard-of-care therapies. Despite these advances, mutations in TP53 are associated with inferior response to both therapies and represent an area of unmet clinical need. Novel strategies with immune-targeted therapies such as CD47 monoclonal antibodies appear active in early-phase studies, but randomized studies have yet to report outcomes leading to approval. Allogeneic transplant remains the only known curative therapy for many of these cases. Nonetheless, pretransplant high-risk molecular features of secondary AML are associated with inferior outcome despite transplantation. An optimal approach to secondary AML is yet to be determined.

TP53-Mutated Myelodysplastic Syndrome and Acute Myeloid Leukemia: Biology, Current Therapy, and Future Directions

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) form a distinct group of myeloid disorders with dismal outcomes. TP53-mutated MDS and AML have lower response rates to either induction chemotherapy, hypomethylating agent-based regimens, or venetoclax-based therapies compared with non-TP53-mutated counterparts and a poor median overall survival of 5 to 10 months. Recent advances have identified novel pathogenic mechanisms in TP53-mutated myeloid malignancies, which have the potential to improve treatment strategies in this distinct clinical subgroup. In this review, we discuss recent insights into the biology of TP53-mutated MDS/AML, current treatments, and emerging therapies, including immunotherapeutic and nonimmune-based approaches for this entity.

SIGNIFICANCE

Emerging data on the impact of cytogenetic aberrations, TP53 allelic burden, immunobiology, and tumor microenvironment of TP53-mutated MDS and AML are further unraveling the complexity of this disease. An improved understanding of the functional consequences of TP53 mutations and immune dysregulation in TP53-mutated AML/MDS coupled with dismal outcomes has resulted in a shift from the use of cytotoxic and hypomethylating agent-based therapies to novel immune and nonimmune strategies for the treatment of this entity. It is hoped that these novel, rationally designed combinations will improve outcomes in this area of significant unmet need.

How I Treat TP53-Mutated Acute Myeloid Leukemia and Myelodysplastic Syndromes

TP53-mutated acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are among the myeloid malignancies with the poorest prognosis. In this review, we analyze the prognosis of these two diseases, focussing particularly on the extent of the mono or biallelic mutation status of TP53 mutation, which is largely correlated with cytogenetic complexity. We discuss the possible/potential improvement in outcome based on recent results obtained with new drugs (especially eprenetapopt and magrolimab). We also focus on the impact of allogeneic hematopoietic stem cell transplantation (aHSCT) including post aHSCT treatment.

Are We Moving the Needle for Patients with TP53-Mutated Acute Myeloid Leukemia?

The currently available therapeutic options for patients with TP53-mutated acute myeloid leukemia (AML) are insufficient, as they translate to a median overall of only 6-9 months, and less than 10% of patients undergoing the most aggressive treatments, such as intensive induction therapy and allogeneic hematopoietic stem cell transplantation, will be cured. The lack of clear differences in outcomes with different treatments precludes the designation of a standard of care. Recently, there has been growing attention on this critical area of need by way of better understanding the biology of TP53 alterations and the disparities in outcomes among patients in this molecular subgroup, reflected in the development and testing of agents with novel mechanisms of action. Promising preclinical and efficacy data exist for therapies that are directed at the p53 protein rendered dysfunctional via mutation or that inhibit the CD47/SIRPα axis or other immune checkpoints such as TIM-3. In this review, we discuss recently attractive and emerging therapeutic agents, their preclinical rationale and the available clinical data as a monotherapy or in combination with the currently accepted backbones in frontline and relapsed/refractory settings for patients with TP53-mutated AML.

Evolution of Therapy for Older Patients With Acute Myeloid Leukemia

ABSTRACT

Most patients with newly diagnosed acute myeloid leukemia (AML) are 65 years or older. The treatment of AML in older patients has been characterized by distinct patient- and disease-related challenges that have impeded the meaningful progress that has been observed in younger patients with AML. Higher rates of comorbidities and frailty contribute to higher rates of treatment-related complications, whereas adverse disease features such as poor-risk genomics and secondary AML are associated with therapeutic resistance and shortened survival. Intensive chemotherapy and allogeneic stem cell transplant, although still considered standard for many newly diagnosed patients with AML, may not be appropriate for a larger subset of older patients with AML. Lower-intensity approaches such as hypomethylating agents have been widely applied for newly diagnosed older and unfit patients with AML, improving tolerability among this subset, but providing more modest response rates. Numerous analyses have attempted to tackle the utility of higher- versus lower-intensity therapy in older AML and identify the factors that can help choose the approach that best optimizes tolerability and efficacy. Recently, a greater understanding of the genomic and biologic heterogeneity of AML has led to better risk stratification and has contributed to the development of specific targeted therapies that are starting to narrow the gap between safety and efficacy. Newly approved agents, such FLT3 (FMS-like tyrosine kinase 3) inhibitors, IDH1 and IDH2 inhibitors, and the BCL2 inhibitor venetoclax, as well postremission maintenance therapy with CC-486 (oral 5-azacitidine), are being systematically incorporated into the evolving treatment of older patients with newly diagnosed AML.

Biomarkers in Acute Myeloid Leukemia: Leveraging Next Generation Sequencing Data for Optimal Therapeutic Strategies

Next generation sequencing (NGS) is routinely used for mutation profiling of acute myeloid leukemia. The extensive application of NGS in hematologic malignancies, and its significant association with the outcomes in multiple large cohorts constituted a proof of concept that AML phenotype is driven by underlying mutational signature and is amenable for targeted therapies. These findings urged incorporation of molecular results into the latest World Health Organization (WHO) sub-classification and integration into risk-stratification and treatment guidelines by the European Leukemia Net. NGS mutation profiling provides a large amount of information that guides diagnosis and management, dependent on the type and number of gene mutations, variant allele frequency and amenability to targeted therapeutics. Hence, molecular mutational profiling is an integral component for work-up of AML and multiple leukemic entities. In addition, there is a vast amount of informative data that can be obtained from routine clinical NGS sequencing beyond diagnosis, prognostication and therapeutic targeting. These include identification of evidence regarding the ontogeny of the disease, underlying germline predisposition and clonal hematopoiesis, serial monitoring to assess the effectiveness of therapy and resistance mutations, which have broader implications for management. In this review, using a few prototypic genes in AML, we will summarize the clinical applications of NGS generated data for optimal AML management, with emphasis on the recently described entities and Food and Drug Administration approved target therapies.

Outcomes of TP53-mutant acute myeloid leukemia with decitabine and venetoclax

BACKGROUND

TP53 mutation (TP53mut ) confers an adverse prognosis in acute myeloid leukemia (AML). Venetoclax with hypomethylating agents is a current standard for older patients; however, recent reports suggest that TP53mut confers resistance to venetoclax. The authors investigated the outcomes of patients with TP53mut AML who were treated with a 10-day decitabine and venetoclax (DEC10-VEN) (ClinicalTrials.gov identifier NCT03404193).

METHODS

Patients with newly diagnosed AML received decitabine 20 mg/m2 for 10 days every 4 to 6 weeks for induction, followed by decitabine for 5 days after response. The venetoclax dose was 400 mg daily. TP53mut was identified in bone marrow samples using next-generation sequencing, with sensitivity of 5%. Outcomes were analyzed according to European LeukemiaNet 2017 guidelines.

RESULTS

Among 118 patients (median age, 72 years; age range, 49-89 years), 63 (53%) had secondary AML, 39 (33%) had AML with complex karyotype, and 35 (30%) had TP53mut AML. The median TP53 variant allele frequency was 32% (interquartile range, 16%-65%), 8 patients (23%) had only a single TP53 mutation, 15 (43%) had multiple mutations, and 12 (34%) had mutation and deletion. Outcomes were significantly worse in patients who had TP53mut AML compared with those who had wild-type TP53 AML, with an overall response rate of 66% vs 89% (P = .002), a complete response/complete response with incomplete hematologic recovery rate of 57% vs 77% (P = .029), and a 60-day mortality of 26% vs 4% (P < .001), respectively. Patients with TP53mut versus wild-type TP53 had shorter overall survival at 5.2 versus 19.4 months, respectively (hazard ratio, 4.67; 95% CI, 2.44-8.93; P < .0001), and shorter relapse-free survival at 3.4 versus 18.9 months (hazard ratio, 4.80; 95% CI, 1.97-11.69; P < .0001), respectively. Outcomes with DEC10-VEN in patients with TP53mut AML were comparable to historical results with 10-day decitabine alone.

CONCLUSIONS

Patients with TP53mut AML have lower response rates and shorter survival with DEC10-VEN.

Dose intensity for induction in acute myeloid leukemia: what, when, and for whom?

Intensive chemotherapy has been the backbone of the treatment of acute myeloid leukemia (AML) for decades. However, an increase in novel targeted agents, which has been brought about in part by a deeper understanding of the genetic makeup of AML, has led to remission-inducing regimens that do not require traditional cytotoxic agents. Combinations of a hypomethylating agent (HMA) and venetoclax have doubled the chance of remission for patients considered unfit for induction chemotherapy who would have traditionally been offered singleagent HMA. In fact, this regimen may rival the complete remission rate achieved with induction chemotherapy for certain populations such as the very elderly and those with secondary AML, but equivalency has yet to be established. Further advances include the addition of gemtuzumab ozogamicin and FLT3 inhibitors to induction chemotherapy, which improves survival for patients with core-binding factor and FLT3-mutated AML, respectively. Still, much work is needed to improve the outcomes of the highest-risk subgroups: frail patients and those with high-risk cytogenetics and/or TP53 mutations. Promisingly, the landscape of AML therapy is shifting dramatically and no longer is intensity, when feasible, always the best answer for AML.

Acute Myeloid Leukemia: Historical Perspective and Progress in Research and Therapy Over 5 Decades

With the Food and Drug Administration approval of 9 agents for different acute myeloid leukemia (AML) indications, the prognosis and management of AML is evolving rapidly. Herein, we review the important milestones in the history of AML research and therapy, discuss insights regarding prognostic assessment and prediction of treatment outcome, detail practical supportive care measures, and summarize the current treatment landscape and areas of evolving research.

Acute myeloid leukemia: Treatment and research outlook for 2021 and the MD Anderson approach

The unraveling of the pathophysiology of acute myeloid leukemia (AML) has resulted in rapid translation of the information into clinical practice. After more than 40 years of slow progress in AML research, the US Food and Drug Administration has approved nine agents for different AML treatment indications since 2017. In this review, we detail the progress that has been made in the research and treatment of AML, citing key publications related to AML research and therapy in the English literature since 2000. The notable subsets of AML include acute promyelocytic leukemia (APL), core-binding factor AML (CBF-AML), AML in younger patients fit for intensive chemotherapy, and AML in older/unfit patients (usually at the age cutoff of 60-70 years). We also consider within each subset whether the AML is primary or secondary (therapy-related, evolving from untreated or treated myelodysplastic syndrome or myeloproliferative neoplasm). In APL, therapy with all-trans retinoic acid and arsenic trioxide results in estimated 10-year survival rates of ≥80%. Treatment of CBF-AML with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin (GO) results in estimated 10-year survival rates of ≥75%. In younger/fit patients, the "3+7" regimen (3 days of daunorubicin + 7 days of cytarabine) produces less favorable results (estimated 5-year survival rates of 35%; worse in real-world experience); regimens that incorporate high-dose cytarabine, adenosine nucleoside analogs, and GO are producing better results. Adding venetoclax, FLT3, and IDH inhibitors into these regimens has resulted in encouraging preliminary data. In older/unfit patients, low-intensity therapy with hypomethylating agents (HMAs) and venetoclax is now the new standard of care. Better low-intensity regimens incorporating cladribine, low-dose cytarabine, and other targeted therapies (FLT3 and IDH inhibitors) are emerging. Maintenance therapy now has a definite role in the treatment of AML, and oral HMAs with potential treatment benefits are also available. In conclusion, AML therapy is evolving rapidly and treatment results are improving in all AML subsets as novel agents and strategies are incorporated into traditional AML chemotherapy. LAY SUMMARY: Ongoing research in acute myeloid leukemia (AML) is progressing rapidly. Since 2017, the US Food and Drug Administration has approved 10 drugs for different AML indications. This review updates the research and treatment pathways for AML.

Acute myeloid leukemia: current progress and future directions

Progress in the understanding of the biology and therapy of acute myeloid leukemia (AML) is occurring rapidly. Since 2017, nine agents have been approved for various indications in AML. These included several targeted therapies like venetoclax, FLT3 inhibitors, IDH inhibitors, and others. The management of AML is complicated, highlighting the need for expertise in order to deliver optimal therapy and achieve optimal outcomes. The multiple subentities in AML require very different therapies. In this review, we summarize the important pathophysiologies driving AML, review current therapies in standard practice, and address present and future research directions.

Individualizing Treatment for Newly Diagnosed Acute Myeloid Leukemia

OPINION STATEMENT

There is increasing awareness that AML is a widely heterogeneous disease, not only based on clinical characteristics and demographics of the patients we treat but also based on the genomics of the disease. Wider accessibility to next-generation DNA sequencing in AML has identified recurrent genetic abnormalities that drive disease biology, define overall prognosis, and predict for response to newly developed target-specific therapies. This knowledge has allowed the field to move away from a "one-size-fits-all" approach in newly diagnosed AML, to a more thoughtful, individualized approachy based on these factors. The first steps in realizing this new approach involve developing systems to efficiently obtain and analyze patient- and disease-related factors prior to starting therapy and having available clinical trials to address each subtype.

The face of remission induction

Acute myeloid leukaemia (AML) is a heterogeneous disease in which prognosis is determined by cytogenetic and molecular aberrations as well as patient-related factors, including age, prior haematologic disorders, and comorbidities. Despite the diverse disease biology, the standard of care for remission induction therapy has changed very little since its inception in 1973. Next generation sequencing has helped to increase our knowledge of the disease pathogenesis, allowing us to develop targeted and possibly more effective treatment options. Seven new agents have been approved for the treatment of AML since 2017, all of which are directed toward a specific molecular subtype or patient population. With the advent of these therapies, a more optimal, patient-specific approach rather than the historical 'one-size fits all' model can be utilised. This review will discuss the role of these novel therapies in the remission induction setting.

Guadecitabine (SGI-110): an investigational drug for the treatment of myelodysplastic syndrome and acute myeloid leukemia

Introduction: The incidence of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) is increasing with the aging population. Prognosis and overall survival (OS) remain poor in elderly patients and in those not eligible for intensive treatment. Hypomethylating agents (HMAs) have played an important role in this group of patients but their efficacy is limited. Areas covered: This article reviews the mechanism of action, pharmacology, safety profile and clinical efficacy of subcutaneous guadecitabine, a second-generation DNA methylation inhibitor in development for the treatment of AML and MDS. Expert opinion: Although guadecitabine did not yield improved complete remission (CR) rates and OS compared to the control arm in patients with treatment-naïve AML who were ineligible for intensive chemotherapy, subgroup analysis in patients who received ≥4 cycles of therapy demonstrated superior outcomes in favor of guadecitabine. Given its stability, ease of administration, safety profile and prolonged exposure time, guadecitabine would be the more appropriate HMA, replacing azacitidine and decitabine, to be used combination treatment regimens in patients with myeloid malignancies.