TP53 Mutations in AML Patients Are Associated with Dismal Clinical Outcome Irrespective of Frontline Induction Regimen and Allogeneic Hematopoietic Cell Transplantation

Tetrahydrobenzimidazole TMQ0153 targets OPA1 and restores drug sensitivity in AML via ROS-induced mitochondrial metabolic reprogramming

BACKGROUND

Acute myeloid leukemia (AML) is a highly aggressive cancer with a 5-year survival rate of less than 35%. It is characterized by significant drug resistance and abnormal energy metabolism. Mitochondrial dynamics and metabolism are crucial for AML cell survival. Mitochondrial fusion protein optic atrophy (OPA)1 is upregulated in AML patients with adverse mutations and correlates with poor prognosis.

METHOD

This study investigated targeting OPA1 with TMQ0153, a tetrahydrobenzimidazole derivative, to disrupt mitochondrial metabolism and dynamics as a novel therapeutic approach to overcome treatment resistance. Effects of TMQ0153 treatment on OPA1 and mitofusin (MFN)2 protein levels, mitochondrial morphology, and function in AML cells. In this study, we examined reactive oxygen species (ROS) production, oxidative phosphorylation (OXPHOS) inhibition, mitochondrial membrane potential (MMP) depolarization, and apoptosis. Additionally, metabolic profiling was conducted to analyze changes in metabolic pathways.

RESULTS

TMQ0153 treatment significantly reduced OPA1 and mitofusin (MFN)2 protein levels and disrupted the mitochondrial morphology and function in AML cells. This increases ROS production and inhibits OXPHOS, MMP depolarization, and caspase-dependent apoptosis. Metabolic reprogramming was observed, shifting from mitochondrial respiration to glycolysis and impaired respiratory chain activity. Profiling revealed reduced overall metabolism along with changes in the glutathione (GSH)/oxidized glutathione (GSSG) and NAD⁺/NADH redox ratios. TMQ0153 treatment reduces tumor volume and weight in MV4-11 xenografts in vivo. Combination therapies with TMQ0153 and other AML drugs significantly reduced the leukemic burden and prolonged survival in NOD scid gamma (NSG) mice xenografted with U937-luc and MOLM-14-luc cells.

CONCLUSION

TMQ0153 targets mitochondrial dynamics by inhibiting OPA1, inducing metabolic reprogramming, and triggering apoptosis in AML cells. It enhances the efficacy of existing AML therapies and provides a promising combination treatment approach that exploits mitochondrial vulnerability and metabolic reprogramming to improve treatment outcomes in AML.

Mutation dynamics from diagnosis to relapse in acute myeloid leukemia with chromosomal 7 deletions

Monosomy 7 and 7q deletions (-7/del(7q)) are the most common adverse cytogenetic event in acute myeloid leukemia (AML), linked to high relapse rates. We analyzed 115 AML patients with -7/del(7q) who achieved remission after induction therapy to characterize the mutational landscape from diagnosis to relapse. Median overall survival (OS) was 10.4 months, with improved survival in patients without TP53 mutation (13.04 vs. 8.6 months) or complex karyotype (12.4 vs. 8.6 months). TP53 mutations were most frequent (67% of cases at diagnosis) and persisted in 97% of patients at relapse. At time of relapse, patients with TP53 mutations had fewer co-occurring mutations in ASXL1, RUNX1, NRAS, PTPN11 and SRSF2 compared to TP53 wild-type patients. Patients with mutated TP53 and co-mutation in NF1, BCORL1, GATA2, or RUNX1 had shorter relapse-free survival (2 vs. 5 months) and OS (7.2 vs. 10.4 months) than those with TP53 mutation alone. Allogeneic transplant improved OS significantly, regardless of TP53 status.

Transplantation outcomes of TP53-mutant AML and MDS: a single transplantation center experience of 63 patients

Allogeneic hematopoietic stem cell transplantation is recommended for TP53-mutant acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) despite a high relapse rate and poor survival. To understand TP53 alterations on a molecular level and define stratified prognostic outcomes following transplantation, we performed targeted next-generation sequencing on 63 patients who underwent transplantation for TP53-mutant AML/MDS and profiled their molecular spectrum. Sixty-eight TP53 mutations were detected, with a median variant allele frequency of 46.8%. Copy number alterations at the TP53 locus were present in 19 patients (30%). Complex karyotype was detected in 48 patients (76%) and was significantly associated with larger TP53 clone size, bi-allelic status, and the absence of concurrent mutations, reflecting the high TP53 mutational burden. Specifically, 51 patients (81%) with the dominant TP53 clone greatly overlapped with those with the complex karyotype. Multivariable overall survival (OS) analysis identified AML (hazard ratio [HR], 2.51; P = 0.03) and TP53 clonal dominance (HR, 5.30; P = 0.002) as prognostic factors. One-year OS was worse in AML with the dominant TP53 clone than in others (13% vs 61%; P < 0.001). Our results underscore the utility of mutational profile-guided risk stratification in patients with TP53-mutant AML/MDS, and could aid in transplantation-related decision-making.

Diverse real-life outcomes after intensive risk-adapted therapy for 1034 AML patients from the CETLAM Group

Given the heterogeneity of acute myeloid leukemia patients, it is necessary to identify patients considered fit for intensive therapy but who will perform poorly, and in whom alternative approaches deserve investigation. We analyzed 1034 fit adults ≤70 years intensively treated between 2012 and 2022 in the CETLAM group. Young adults ( ≤ 60 years) presented higher remission rates and improved survival than older adults above that age (CR 79% vs. 73%; p = 0.03 and 4-yr OS 53% vs. 33%; p < 0.001). Remission and survival outcomes varied among different genetic subsets. An especially adverse genetic group included complex, monosomal karyotype, TP53 alterations (deleted/mutated), and MECOMr. Transplant feasibility in this very adverse risk group was low, and OS and EFS at 4 years were 14% and 12%, in contrast to 70% and 57% in the favorable group and 38% and 32% in all other patients. We integrated clinical and genetic data into the Intensive Chemotherapy Score for AML (ICSA) with 6-risk categories with significantly different remission rates and OS, validated in another cohort of 581 AML patients from a previous CETLAM protocol. In summary, we identified groups of fit patients that benefit differently from an intensive approach which may be helpful in future treatment decisions.

[Place of hematopoietic stem cell transplantation for very high risk acute myeloblastic leukemia and myelodysplastic syndromes (SFGM-TC)]

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a potentially curative treatment for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). However, these transplants are complicated by a high rate of relapse in very high cytogenetic risk or refractory diseases. The benefit of this therapeutic strategy for these serious malignant hemopathies could therefore be reassessed. As part of the 14th workshop for the harmonization of allograft practices organized by the francophone society of bone marrow transplantation and cellular therapy (SFGM-TC) (SFGM-TC) in Lille in September 2023, the role of allograft for very high risk or refractory AML and MDS was challenged after analysis of published studies.

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.

Therapy-related myeloid neoplasms with single-hit TP53 mutations share the clinical, molecular, and survival characteristics of their multi-hit counterparts

Recent updates in the classification of myeloid neoplasms (MNs) recognize the poor prognostic impact of TP53 mutations, with particular emphasis on the TP53 allele status. Studies on the effect of TP53 allele status exclusively in therapy-related MNs (t-MNs) are lacking. We compared the clinicopathologic and survival characteristics of t-MNs with single-hit (SH) and multi-hit (MH) TP53 mutations. A total of 71 TP53-mutated t-MNs were included, including 56 (78.9%) MH and 15 (21.1%) SH. Both groups showed comparable genetic profiles with an excess of high-risk karyotypes and a paucity of other co-mutated genes. TP53 was the sole detectable mutation in 73.3% of SH and 75.0% of MH cases. The overall survival (OS) of SH TP53-mutated t-MNs was not significantly different from MH cases (median survival: 233 vs.273 days, p = 0.70). Our findings suggest that t-MNs with SH TP53 mutations share the poor prognostic and biologic profile of their MH counterparts.

Chemotherapy resistance in acute myeloid leukemia is mediated by A20 suppression of spontaneous necroptosis

Acute myeloid leukemia (AML) is a deadly hematopoietic malignancy. Although many patients achieve complete remission with standard induction therapy, a combination of cytarabine and anthracycline, ~40% of patients have induction failure. These refractory patients pose a treatment challenge, as they do not respond to salvage therapy or allogeneic stem cell transplant. Herein, we show that AML patients who experience induction failure have elevated expression of the NF-κB target gene tumor necrosis factor alpha-induced protein-3 (TNFAIP3/A20) and impaired necroptotic cell death. A20High AML are resistant to anthracyclines, while A20Low AML are sensitive. Loss of A20 in AML restores sensitivity to anthracycline treatment by inducing necroptosis. Moreover, A20 prevents necroptosis in AML by targeting the necroptosis effector RIPK1, and anthracycline-induced necroptosis is abrogated in A20High AML. These findings suggest that NF-κB-driven A20 overexpression plays a role in failed chemotherapy induction and highlights the potential of targeting an alternative cell death pathway in AML.

Continued decitabine/all-trans retinoic acid treatment: extended complete remission in an elderly AML patient with multi-hit TP53 lesions and complex-monosomal karyotype

DNA-hypomethylating agents (HMAs) induce notable remission rates in AML/MDS patients with TP53 mutations; however, secondary resistance often develops rapidly. In the DECIDER trial (NCT00867672), elderly AML patients (also those with adverse genetics) randomized to all-trans retinoic acid (ATRA) added to decitabine (DEC) attained significantly delayed time-to-resistance. An 82-year-old patient with a non-disruptive, in-frame TP53 mutation (p.Cys238_Asn239delinsTyr, VAF 90%) and complex-monosomal karyotype attained a complete hematologic and cytogenetic remission with DEC + ATRA, with 3.7 years survival after 30 treatment cycles that were well-tolerated. Further HMA + ATRA studies appear warranted in AML/MDS patients of different genetic risk groups ineligible for more intensive treatment.Trial registration: This trial was registered at ClinicalTrials.gov identifier: NCT00867672.

Patients with TP53-Mutated Acute Myeloid Leukemia Receiving Intensive Induction Therapy Have Superior Outcomes Due to a Higher Rate of Salvage Therapy: A Single Institution, Retrospective Study

BACKGROUND

TP53 mutations (TP53m) define the most treatment-refractory acute myeloid leukemia (AML) subtype. Optimal treatment approaches have not been established in this setting. We reviewed our institutional experience to identify therapy sequencing, treatment response, and survival patterns in these patients.

METHODS

This study was a single-center, retrospective cohort analysis.

RESULTS

Our cohort includes 86 TP53m and 337 TP53 wild-type (TP53wt) adult AML patients. TP53m AML patients presented with lower bone marrow and peripheral blasts; none presented with hyperleukocytosis. Patients who received intensive treatment up front demonstrated superior overall survival (OS) over those receiving first-line non-intensive therapy (2-year OS 22% versus 7%; p = 0.02). However, the complete remission (CR) rates among the first-line intensive and non-intensive therapy groups were comparable (21.9% and 29.4%, respectively, p = 0.49). The improved OS is therefore attributed to superior cumulative CR in the intensive group. First-line intensively treated patients were more likely to receive and respond to salvage, leading to a cumulative CR rate of 65.7% (versus 29.4%, p = 0.003). Achieving CR at any point is strongly associated with superior survival outcomes with 2-year OS of 31% versus 0% for those not achieving CR ever (p < 0.01).

CONCLUSIONS

We find that TP53m AML rarely presents with oncological emergencies, suggesting that clinical trial enrollment is feasible in this group. Additionally, in our cohort, intensive induction therapies lead to superior survival outcomes attributed to successful salvage therapy. These data suggest that strategic therapy sequencing and salvage therapy may be important in optimizing outcomes for TP53m AML patients.

Impact of p53-associated acute myeloid leukemia hallmarks on metabolism and the immune environment

Acute myeloid leukemia (AML), an aggressive malignancy of hematopoietic stem cells, is characterized by the blockade of cell differentiation, uncontrolled proliferation, and cell expansion that impairs healthy hematopoiesis and results in pancytopenia and susceptibility to infections. Several genetic and chromosomal aberrations play a role in AML and influence patient outcomes. TP53 is a key tumor suppressor gene involved in a variety of cell features, such as cell-cycle regulation, genome stability, proliferation, differentiation, stem-cell homeostasis, apoptosis, metabolism, senescence, and the repair of DNA damage in response to cellular stress. In AML, TP53 alterations occur in 5%-12% of de novo AML cases. These mutations form an important molecular subgroup, and patients with these mutations have the worst prognosis and shortest overall survival among patients with AML, even when treated with aggressive chemotherapy and allogeneic stem cell transplant. The frequency of TP53-mutations increases in relapsed and recurrent AML and is associated with chemoresistance. Progress in AML genetics and biology has brought the novel therapies, however, the clinical benefit of these agents for patients whose disease is driven by TP53 mutations remains largely unexplored. This review focuses on the molecular characteristics of TP53-mutated disease; the impact of TP53 on selected hallmarks of leukemia, particularly metabolic rewiring and immune evasion, the clinical importance of TP53 mutations; and the current progress in the development of preclinical and clinical therapeutic strategies to treat TP53-mutated disease.

Transplant versus no transplant in myelodysplastic syndrome and acute myeloid leukemia with TP53 mutation; a referral center experience

A remarkably high rate of post-transplant relapse in patients with TP53-mutated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) calls to question the utility of allogeneic stem cell transplant (HSCT). We, therefore, performed a retrospective analysis to compare the outcomes between HSCT (N = 38) versus non-HSCT (N = 45) approaches. Patients in the HSCT cohort were younger (median age 63 vs. 72) while patients in the non-HSCT cohort more commonly had complex karyotype with chromosome 17 aberrancy and 5q deletion (p < .01). A total of 69 TP53 variants including 64 pathogenic variants, and 5 variants of undetermined significance were detected. Nine patients (4 in HSCT and 5 in non-HSCT) had multi-hit TP53 variants. After induction: 57.9% versus 56.6% in the HSCT versus non-HSCT cohort achieved morphologic complete remission. Median time to HSCT was 6 months and median follow-up was 15.1 months for HSCT and 5.7 months for non-HSCT. Median disease-free survival (DFS) and overall survival (OS) were 11.7 and 15.9 months for HSCT, and 4.1 and 5.7 months for non-HSCT cohorts, respectively. Non-relapse mortality at 12 months was 22% versus 44% for HSCT versus non-HSCT. In the HSCT cohort, the rate of grade II-IV acute and chronic graft-versus-host disease (GVHD) was 55% and 18%, respectively. None of the patients from the non-HSCT cohort were alive while four patients from the HSCT cohort were alive, in remission, and without GVHD (GRFS) at the time of abstraction. Better treatment strategies for patients with TP53-mutated MDS/AML remain an area of unmet clinical need.

Transplant Eligible and Ineligible Elderly Patients with AML-A Genomic Approach and Next Generation Questions

The management of elderly patients diagnosed with acute myelogenous leukemia (AML) is complicated by high relapse risk and comorbidities that often preclude access to allogeneic hematopoietic cellular transplantation (allo-HCT). In recent years, fast-paced FDA drug approval has reshaped the therapeutic landscape, with modest, albeit promising improvement in survival. Still, AML outcomes in elderly patients remain unacceptably unfavorable highlighting the need for better understanding of disease biology and tailored strategies. In this review, we discuss recent modifications suggested by European Leukemia Network 2022 (ELN-2022) risk stratification and review recent aging cell biology advances with the discussion of four AML cases. While an older age, >60 years, does not constitute an absolute contraindication for allo-HCT, the careful patient selection based on a detailed and multidisciplinary risk stratification cannot be overemphasized.

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.

Utility or futility? A contemporary approach to allogeneic hematopoietic cell transplantation for TP53-mutated MDS/AML

ABSTRACT

TP 53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are among the most lethal malignancies, characterized by dismal outcomes with currently available therapies. Allogeneic hematopoietic cell transplantation (allo-HCT) is widely thought to be the only treatment option to offer durable disease control. However, outcomes with allo-HCT in this context are quite poor, calling into question the utility of transplantation. In this review, we summarize the latest data on allo-HCT outcomes in this subgroup, evaluating the limitations of available evidence; we review the molecular heterogeneity of this disease, delineating outcomes based on distinct biological features to aid in patient selection; and we critically examine whether allo-HCT should be routinely applied in this disease on the basis of currently available data. We propose that the exceptionally poor outcomes of patients with TP53-mutated MDS/AML with biallelic loss and/or adverse-risk cytogenetics should motivate randomized-controlled trials of HCT vs non-HCT to determine whether transplantation can prolong survival and/or positively impact other clinically relevant outcomes such as patient-reported outcomes or healthcare resource utilization in this disease subset. Without dedicated prospective randomized trials, selecting who may actually derive benefit from allo-HCT for TP53-mutated MDS/AML can be described as ambiguous guesswork and must be carefully contemplated.

TP53 Mutation in Acute Myeloid Leukemia: An Old Foe Revisited

INTRODUCTION

TP53 is the most commonly mutated gene in human cancers and was the first tumor suppressor gene to be discovered in the history of medical science. Mutations in the TP53 gene occur at various genetic locations and exhibit significant heterogeneity among patients. Mutations occurring primarily within the DNA-binding domain of TP53 result in the loss of the p53 protein's DNA-binding capability. However, a complex phenotypic landscape often combines gain-of-function, dominant negative, or altered specificity features. This complexity poses a significant challenge in developing an effective treatment strategy, which eradicates TP53-mutated cancer clones. This review summarizes the current understanding of TP53 mutations in AML and their implications. TP53 mutation in AML: In patients with acute myeloid leukemia (AML), six hotspot mutations (R175H, G245S, R248Q/W, R249S, R273H/S, and R282W) within the DNA-binding domain are common. TP53 mutations are frequently associated with a complex karyotype and subgroups of therapy-related or secondary AML. The presence of TP53 mutation is considered as a poor prognostic factor. TP53-mutated AML is even classified as a distinct subgroup of AML by itself, as TP53-mutated AML exhibits a significantly distinct landscape in terms of co-mutation and gene expression profiles compared with wildtype (WT)-TP53 AML.

CLINICAL IMPLICATIONS

To better predict the prognosis in cancer patients with different TP53 mutations, several predictive scoring systems have been proposed based on screening experiments, to assess the aggressiveness of TP53-mutated cancer cells. Among those scoring systems, a relative fitness score (RFS) could be applied to AML patients with TP53 mutations in terms of overall survival (OS) and event-free survival (EFS). The current standard treatment, which includes cytotoxic chemotherapy and allogeneic hematopoietic stem cell transplantation, is largely ineffective for patients with TP53-mutated AML. Consequently, most patients with TP53-mutated AML succumb to leukemia within several months, despite active anticancer treatment. Decitabine, a hypomethylating agent, is known to be relatively effective in patients with AML. Numerous trials are ongoing to investigate the effects of novel drugs combined with hypomethylating agents, TP53-targeting agents or immunologic agents.

CONCLUSIONS

Developing an effective treatment strategy for TP53-mutated AML through innovative and multidisciplinary research is an urgent task. Directly targeting mutated TP53 holds promise as an approach to combating TP53-mutated AML, and recent developments in immunologic agents for AML offer hope in this field.