Prognostic value of TP53 gene mutations in myelodysplastic syndromes and acute myeloid leukemia treated with azacitidine

Enhanced ALOX12 Gene Expression Predicts Therapeutic Susceptibility to 5-Azacytidine in Patients with Myelodysplastic Syndromes

5-azacytidine (AZA), a representative DNA-demethylating drug, has been widely used to treat myelodysplastic syndromes (MDS). However, it remains unclear whether AZA's DNA demethylation of any specific gene is correlated with clinical responses to AZA. In this study, we investigated genes that could contribute to the development of evidence-based epigenetic therapeutics with AZA. A DNA microarray identified that AZA specifically upregulated the expression of 438 genes in AZA-sensitive MDS-L cells but not in AZA-resistant counterpart MDS-L/CDA cells. Of these 438 genes, the ALOX12 gene was hypermethylated in MDS-L cells but not in MDS-L/CDA cells. In addition, we further found that (1) the ALOX12 gene was hypermethylated in patients with MDS compared to healthy controls; (2) MDS classes with excess blasts showed a relatively lower expression of ALOX12 than other classes; (3) a lower expression of ALOX12 correlated with higher bone marrow blasts and a shorter survival in patients with MDS; and (4) an increased ALOX12 expression after AZA treatment was associated with a favorable response to AZA treatment. Taking these factors together, an enhanced expression of the ALOX12 gene may predict favorable therapeutic responses to AZA therapy in MDS.

Comparison of the 2022 world health organization classification and international consensus classification in myelodysplastic syndromes/neoplasms

In 2022, two novel classification systems for myelodysplastic syndromes/neoplasms (MDS) have been proposed: the International Consensus Classification (ICC) and the 2022 World Health Organization (WHO-2022) classification. These two contemporary systems exhibit numerous shared features but also diverge significantly in terminology and the definition of new entities. Thus, we retrospectively validated the ICC and WHO-2022 classification and found that both systems promoted efficient segregation of this heterogeneous disease. After examining the distinction between the two systems, we showed that a peripheral blood blast percentage ≥ 5% indicates adverse survival. Identifying MDS/acute myeloid leukemia with MDS-related gene mutations or cytogenetic abnormalities helps differentiate survival outcomes. In MDS, not otherwise specified patients, those diagnosed with hypoplastic MDS and single lineage dysplasia displayed a trend of superior survival compared to other low-risk MDS patients. Furthermore, the impact of bone marrow fibrosis on survival was less pronounced within the ICC framework. Allogeneic transplantation appears to improve outcomes for patients diagnosed with MDS with excess blasts in the ICC. Therefore, we proposed an integrated system that may lead to the accurate diagnosis and advancement of future research for MDS. Prospective studies are warranted to validate this refined classification.

Real-World Outcome and Prognostic Factors in MDS Patients Treated with Azacitidine-A Retrospective Analysis

Azacitidine (AZA) is recognized as a vital drug used in the therapy of myelodysplastic syndromes (MDS) due to its beneficial effect on survival and quality of life. Nevertheless, many patients fail to respond to AZA treatment, as prognostic factors still are not identified. The present retrospective analysis included 79 patients with MDS treated with AZA as first-line therapy in a real-life setting. The percentage of patients with good, intermediate, and poor cytogenetics was 46.8%, 11.4%, and 34.2%, respectively. The overall response rate (complete remission [CR], partial remission [PR], and hematological improvement [HI]) was 24%. The CR, PR, and HI rates were 13.9%, 2.5%, and 7.6%, respectively. Stable disease (SD) was documented in 40.5% of patients. The median overall survival (OS) and progression-free survival (PFS) were 17.6 and 14.96 months, respectively. Patients with ORR and SD had a significantly longer median OS (23.8 vs. 5.7 months, p = 0.0005) and PFS (19.8 vs. 3.5 months, p < 0.001) compared to patients who did not respond to AZA. In univariate analysis, only an unfavorable cytogenetic group was a prognostic factor of a lower response rate (p = 0.03). In a multivariate model, older age (p = 0.047), higher IPSS (International Prognostic Scoring System) risk (p = 0.014), and higher IPSS-R cytogenetic risk (p = 0.004) were independent factors of shorter OS. Independent prognostic factors for shorter PFS were age (p = 0.001), IPSS risk (p = 0.02), IPSS cytogenetic risk (p = 0.002), and serum ferritin level (p = 0.008). The safety profile of AZA was predictable and consistent with previous studies. In conclusion, our study confirms the efficacy and safety of AZA in a real-world population and identifies potential biomarkers for response and survival.

Opportunities and challenges for anti-CD47 antibodies in hematological malignancies

CD47 is a cell-surface ligand that is overexpressed in various malignancies and that binds to SIRPα on macrophages to promote tumor cell evasion of phagocytosis. Blocking the CD47-SIRPα axis can increase the phagocytosis of macrophages to exert antitumor effects. CD47-based immunotherapy is a current research focus. The combination of anti-CD47 antibodies with other drugs has shown encouraging response rates in patients with hematological tumors, but side effects also occur. Bispecific antibodies and SIRPα/Fc fusion proteins appear to balance the efficacy and safety of treatment. We review the latest clinical research advances and discuss the opportunities and challenges associated with CD47-based immunotherapy for hematological malignancies.

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.

Pharmacological reactivation of p53 in the era of precision anticancer medicine

p53, which is encoded by the most frequently mutated gene in cancer, TP53, is an attractive target for novel cancer therapies. Despite major challenges associated with this approach, several compounds that either augment the activity of wild-type p53 or restore all, or some, of the wild-type functions to p53 mutants are currently being explored. In wild-type TP53 cancer cells, p53 function is often abrogated by overexpression of the negative regulator MDM2, and agents that disrupt p53-MDM2 binding can trigger a robust p53 response, albeit potentially with induction of p53 activity in non-malignant cells. In TP53-mutant cancer cells, compounds that promote the refolding of missense mutant p53 or the translational readthrough of nonsense mutant TP53 might elicit potent cell death. Some of these compounds have been, or are being, tested in clinical trials involving patients with various types of cancer. Nonetheless, no p53-targeting drug has so far been approved for clinical use. Advances in our understanding of p53 biology provide some clues as to the underlying reasons for the variable clinical activity of p53-restoring therapies seen thus far. In this Review, we discuss the intricate interactions between p53 and its cellular and microenvironmental contexts and factors that can influence p53's activity. We also propose several strategies for improving the clinical efficacy of these agents through the complex perspective of p53 functionality.

Clinical decision-making and treatment of myelodysplastic syndromes

ABSTRACT

The myelodysplastic syndromes (MDSs) constitute a profoundly heterogeneous myeloid malignancy with a common origin in the hemopoietic stem cell compartment. Consequently, patient management and treatment are as heterogeneous. Decision-making includes identifying risk, symptoms, and options for an individual and conducting a risk-benefit analysis. The only potential cure is allogeneic stem cell transplantation, and albeit the fraction of patients with MDS who undergo transplant increase over time because of better management and increased donor availability, a majority are not eligible for this intervention. Current challenges encompass to decrease the relapse risk, the main cause of hematopoietic stem cell transplantation failure. Hypomethylating agents (HMAs) constitute firstline treatment for higher-risk MDSs. Combinations with other drugs as firstline treatment has, to date, not proven more efficacious than monotherapy, although combinations approved for acute myeloid leukemia, including venetoclax, are under evaluation and often used as rescue treatment. The treatment goal for lower-risk MDS is to improve cytopenia, mainly anemia, quality of life, and, possibly, overall survival. Erythropoiesis-stimulating agents (ESAs) constitute firstline treatment for anemia and have better and more durable responses if initiated before the onset of a permanent transfusion need. Treatment in case of ESA failure or ineligibility should be tailored to the main disease mechanism: immunosuppression for hypoplastic MDS without high-risk genetics, lenalidomide for low-risk del(5q) MDS, and luspatercept for MDS with ring sideroblasts. Approved therapeutic options are still scarcer for MDS than for most other hematologic malignancies. Better tools to match disease biology with treatment, that is, applied precision medicines are needed to improve patient outcome.

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.

Postazacitidine clone size predicts long-term outcome of patients with myelodysplastic syndromes and related myeloid neoplasms

Azacitidine is a mainstay of therapy for myelodysplastic syndrome (MDS)-related diseases. The purpose of our study is to elucidate the effect of gene mutations on hematological response and overall survival (OS), particularly focusing on their posttreatment clone size. We enrolled a total of 449 patients with MDS or related myeloid neoplasms. They were analyzed for gene mutations in pretreatment (n = 449) and posttreatment (n = 289) bone marrow samples using targeted-capture sequencing to assess the impact of gene mutations and their posttreatment clone size on treatment outcomes. In Cox proportional hazard modeling, multihit TP53 mutation (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.42-2.91; P < .001), EZH2 mutation (HR, 1.71; 95% CI, 1.14-2.54; P = .009), and DDX41 mutation (HR, 0.33; 95% CI, 0.17-0.62; P < .001), together with age, high-risk karyotypes, low platelets, and high blast counts, independently predicted OS. Posttreatment clone size accounting for all drivers significantly correlated with International Working Group (IWG) response (P < .001, using trend test), except for that of DDX41-mutated clones, which did not predict IWG response. Combined, IWG response and posttreatment clone size further improved the prediction of the original model and even that of a recently proposed molecular prediction model, the molecular International Prognostic Scoring System (IPSS-M; c-index, 0.653 vs 0.688; P < .001, using likelihood ratio test). In conclusion, evaluation of posttreatment clone size, together with the pretreatment mutational profile as well as the IWG response play a role in better prognostication of azacitidine-treated patients with myelodysplasia.

Acute Myeloid Leukemia Treatment in the Elderly: A Comprehensive Review of the Present and Future

BACKGROUND

Acute myeloid leukemia (AML) is a disease of the hematopoietic system that remains a therapeutic challenge despite advances in our understanding of the underlying cancer biology in the past decade. It is also an affliction of the elderly that predominantly affects patients over 60 years of age. Standard therapy involves intensive chemotherapy that is often difficult to tolerate in older populations. Fortunately, recent developments in molecular targeting have shown promising results in treating leukemia, paving the way for novel treatment strategies that are easier to tolerate.

SUMMARY

Venetoclax, a BCL-2 inhibitor, when combined with a hypomethylating agent, has proven to be a highly effective and well-tolerated drug and established itself as a new standard for treating AML in patients who are unfit for standard intensive therapy. Other targeted therapies include clinically proven and FDA-approved agents, such as IDH1/2 inhibitors, FLT3 inhibitors, and Gemtuzumab, as well as newer and more experimental drugs such as magrolimab, PI-kinase inhibitors, and T-cell engaging therapy. Some of the novel agents such as magrolimab and menin inhibitors are particularly promising, providing therapeutic options to a wider population of patients than ever before. Determining who will benefit from intense or novel low-intense therapy remains a challenge, and it requires careful assessment of individual patient's fitness and disease characteristics.

KEY MESSAGES

This article reviews past and current treatment strategies that harness various mechanisms of leukemia-targeting agents and introduces novel therapies on the horizon aimed at exploring therapeutic options for the elderly and unfit patient population. It also provides a strategy to select the best available therapy for elderly patients with both newly diagnosed and relapsed/refractory 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.

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

TP53 mutations are associated with extremely poor outcomes in acute myeloid leukemia (AML). The outcomes of patients with TP53-mutated (TP53^MUT) AML after different frontline treatment modalities are not well established. Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative procedure for AML; however, long-term outcomes among patients with TP53^MUT AML after allo-HCT are dismal, and the benefit of allo-HCT remains controversial. We sought to evaluate the outcomes of patients with TP53^MUT AML after treatment with different frontline induction therapies and allo-HCT. A total of 113 patients with TP53^MUT AML were retrospectively evaluated. Patients with TP53^MUT AML who received intensive or azacitidine-venetoclax induction had higher complete remission rates compared to patients treated with other hypomethylating-agent-based induction regimens. However, OS and EFS were not significantly different among the induction regimen groups. Allo-HCT was associated with improved OS and EFS among patients with TP53^MUT AML; however, allo-HCT was not significantly associated with improved OS or EFS in time-dependent or landmark analysis. While the outcomes of all patients were generally poor irrespective of therapeutic strategy, transplanted patients with lower TP53^MUT variant allele frequency (VAF) at the time of diagnosis had superior outcomes compared to transplanted patients with higher TP53 VAF. Our study provides further evidence that the current standards of care for AML confer limited therapeutic benefit to patients with TP53 mutations.

TP53 Alterations in Myelodysplastic Syndromes and Acute Myeloid Leukemia

TP53 mutations are less frequent in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) than in solid tumors, except in secondary and therapy-related MDS/AMLs, and in cases with complex monosomal karyotype. As in solid tumors, missense mutations predominate, with the same hotspot mutated codons (particularly codons 175, 248, 273). As TP53-mutated MDS/AMLs are generally associated with complex chromosomal abnormalities, it is not always clear when TP53 mutations occur in the pathophysiological process. It is also uncertain in these MDS/AML cases, which often have inactivation of both TP53 alleles, if the missense mutation is only deleterious through the absence of a functional p53 protein, or through a potential dominant-negative effect, or finally a gain-of-function effect of mutant p53, as demonstrated in some solid tumors. Understanding when TP53 mutations occur in the disease course and how they are deleterious would help to design new treatments for those patients who generally show poor response to all therapeutic approaches.

TP53 mutation variant allele frequency of ≥10% is associated with poor prognosis in therapy-related myeloid neoplasms

Revised diagnostic criteria for myeloid neoplasms (MN) issued by the International Consensus Classification (ICC) and the World Health Organization (WHO) recommended major change pertaining to TP53-mutated (TP53mut) MN. However, these assertions have not been specifically examined in therapy-related myeloid neoplasm (t-MN), a subset enriched with TP53mut. We analyzed 488 t-MN patients for TP53mut. At least one TP53mut with variant allele frequency (VAF) ≥ 2% with or without loss of TP53 locus was noted in 182 (37.3%) patients and 88.2% of TP53mut t-MN had a VAF ≥10%. TP53mut t-MN with VAF ≥ 10% had a distinct clinical and biological profile compared to both TP53mut VAF < 10% and wild-type TP53 (TP53wt) cases. Notably, TP53mut VAF ≥ 10% had a significantly shorter survival compared to TP53wt (8.3 vs. 21.6 months; P < 0.001), while the survival of TP53mut VAF < 10% was comparable to TP53wt. Within TP53mut VAF ≥ 10% cohort, the inferior outcomes persisted irrespective of the single- or multi-hit status, co-mutation pattern, or treatments received. Finally, survival of TP53mut patients was poor across all the blast categories and MDS patients with >10% blasts had inferior survival compared to <5%. In summary, TP53mut VAF ≥10% signified a clinically and molecularly homogenous cohort regardless of the allelic status.

Novel high-risk acute myeloid leukemia subgroup with ERG amplification and Biallelic loss of TP53

ETS-related gene (ERG) amplification, observed in 4-6% of acute myeloid leukemia (AML), is associated with unfavorable prognosis. To determine coincident effects of additional genomic abnormalities in AML with ERG amplification (ERGamp), we examined 11 ERGamp cases of 205 newly diagnosed AML using chromosomal microarray analysis and next generation sequencing. ERGamp cases demonstrated a distinct pattern of high genetic complexity: loss of 5q, chromothripsis and TP53 loss of function variants. Remarkably, allelic TP53 loss or loss of heterozygosity (LOH) co-occurring with TP53 inactivating mutation dramatically effected ERGamp tumor patient outcome. In the presence of homozygous TP53 loss of function, ERGamp patients demonstrated no response to induction chemotherapy with median overall survival (OS) of 3.8 months (N = 9). Two patients with heterozygous loss of TP53 function underwent alloSCT without evidence of relapse at one year. Similarly, a validation TCGA cohort, 6 of the 8 ERGamp cases with TP53 loss of function demonstrated median OS of 2.5 months. This suggests that with TP53 mutant ERGamp AML, successive loss of the second TP53 allele, typically by 17p deletion or LOH identifies a specific high-risk subtype of AML patients who are resistant to standard induction chemotherapy and need novel approaches to avert the very poor prognosis.

Therapeutic Targeting of P53: A Comparative Analysis of APR-246 and COTI-2 in Human Tumor Primary Culture 3-D Explants

Background: TP53 is the most commonly mutated gene in human cancer with loss of function mutations largely concentrated in “hotspots” affecting DNA binding. APR-246 and COTI-2 are small molecules under investigation in P53 mutated cancers. APR binds to P53 cysteine residues, altering conformation, while COTI-2 showed activity in P53 mutant tumors by a computational platform. We compared APR-246 and COTI-2 activity in human tumor explants from 247 surgical specimens. Methods: Ex vivo analyses of programmed cell death measured drug-induced cell death by delayed-loss-of-membrane integrity and ATP content. The LC50s were compared by Z-Score. Synergy was conducted by the method of Chou and Talalay, and correlations were performed by Pearson moment. Results: APR-246 and COTI-2 activity favored hematologic neoplasms, but solid tumor activity varied by diagnosis. COTI-2 and APR-246 activity did not correlate (R = 0.1028) (NS). COTI-2 activity correlated with nitrogen mustard, cisplatin and gemcitabine, doxorubicin and selumetinib, with a trend for APR-246 with doxorubicin. For ovarian cancer, COTI-2 showed synergy with cisplatin at 25%. Conclusions: COTI-2 and APR-246 activity differ by diagnosis. A lack of correlation supports distinct modes of action. Cisplatin synergy is consistent with P53’s role in DNA damage. Different mechanisms of action may underlie disease specificity and offer better disease targeting.

The genetics of myelodysplastic syndromes and the opportunities for tailored treatments

Genomic instability, microenvironmental aberrations, and somatic mutations contribute to the phenotype of myelodysplastic syndrome and the risk for transformation to AML. Genes involved in RNA splicing, DNA methylation, histone modification, the cohesin complex, transcription, DNA damage response pathway, signal transduction and other pathways constitute recurrent mutational targets in MDS. RNA-splicing and DNA methylation mutations seem to occur early and are reported as driver mutations in over 50% of MDS patients. The improved understanding of the molecular landscape of MDS has led to better disease and risk classification, leading to novel therapeutic opportunities. Based on these findings, novel agents are currently under preclinical and clinical development and expected to improve the clinical outcome of patients with MDS in the upcoming years. This review provides a comprehensive update of the normal gene function as well as the impact of mutations in the pathogenesis, deregulation, diagnosis, and prognosis of MDS, focuses on the most recent advances of the genetic basis of myelodysplastic syndromes and their clinical relevance, and the latest targeted therapeutic approaches including investigational and approved agents for MDS.

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.

Targeting TP53-Mutated Acute Myeloid Leukemia: Research and Clinical Developments

TP53 is a key tumor suppressor gene that plays an important role in regulating apoptosis, senescence, and DNA damage repair in response to cellular stress. Although somewhat rare, TP53-mutated AML has been identified as an important molecular subgroup with a prognosis that is arguably the worst of any. Survival beyond one year is rare after induction chemotherapy with or without consolidative allogeneic stem cell transplant. Although response rates have been improved with hypomethylating agents, outcomes remain particularly poor due to short response duration. Improvements in our understanding of AML genetics and biology have led to a surge in novel treatment options, though the clinical applicability of these agents in TP53-mutated disease remains largely unknown. This review will focus on the epidemiology, molecular characteristics, and clinical significance of TP53 mutations in AML as well as emerging treatment options that are currently being studied.

Erythroblast predominance without CD41/cyCD41-positive blasts predicts favorable prognosis in patients with myelodysplastic syndromes and acute myeloid leukemias treated with azacitidine

This study examined the prognostic impact of erythroblast predominance (EP) in 61 patients with myelodysplastic syndromes (MDS) (n = 51) or acute myeloid leukemia (n = 10) treated with azacitidine. Median age was 78 years. EP, defined as > 40% erythroblasts and M/E < 1.0, was found in 21 patients, including 9 complex karyotypes (CK). In the 24 CK of the entire cohort, 5 were hyperdiploid and 15 were monosomal karyotype with -5/5q-, and 10 had immunophenotypically CD41/cyCD41 positive blasts (cyCD41+). The complete response (CR) rate was 32.8%. Median follow-up was 14 months, and median overall survival (OS) was 17 months. Although all patients with EP achieved high CR rates (61.9%) and extended OS (28 M, P = 0.056), patients with EP and cyCD41+ blasts had shorter OS (8 M, P = 0.002). EP (HR 0.39, P = 0.009) and cyCD41+ (HR 3.49, P = 0.018) were identified as prognostic factors in multivariate analysis. All patients with cyCD41+ had hyperdiploid or CK with -5/5q-. In conclusion, we divided patients into three risk categories: high (cyCD41+), low (EP without cyCD41+), and intermediate (non-CD41+ and non-EP), and median OS in these categories was 34, 17 and 8 months, respectively (P < 0.001).

Platelet Doubling After First Decitabine Cycle Predicts Response and Survival of Myelodysplastic Syndrome Patients

OBJECTIVE

Although the effect of decitabine on myelodysplastic syndrome (MDS) has been demonstrated, merely a proportion of patients respond to therapy, and no well-recognized predictors have been identified. This study was conducted to investigate the effectiveness of decitabine in real-world clinical practice, and determine the predictive factors of response and overall survival (OS) in MDS patients.

METHODS

Clinical and pathological data were collected from 94 patients and analyzed. These patients were reclassified according to the 2016 World Health Organization classification criteria, and restratified by International Prognostic Scoring System prognostic scores. The response evaluation was performed according to the 2006 modified International Working Group response criteria.

RESULTS

In this study, 62% of patients responded to decitabine. Among these patients, 15 patients (16%) obtained complete remission (CR), 15 patients (16%) obtained marrow CR with hematologic improvement (HI), 20 patients (21%) obtained marrow CR without HI, and 8 patients (9%) only obtained HI, and no patient botained partial remission. The OS of the responders was significantly longer than that of non-responders (67 months vs. 7 months, P<0.001). The OS in patients with and without platelet doubling was significantly different in both the low/intermediate and high/very high risk groups (P=0.0398 and P=0.0330). The multivariate analysis revealed that platelet doubling after the first decitabine cycle is an independent predictor of response and OS in MDS patients (P=0.002 and P=0.008).

CONCLUSION

Decitabine is effective for treating MDS patients in real-world clinical practice. Furthermore, platelet doubling after the first decitabine cycle can be used as a predictor of response and survival in MDS patients.

The beginning of a new therapeutic era in acute myeloid leukemia

In the field of AML, the early 2000s were shaped by the advent of novel molecular biology technologies including high-throughput sequencing that improved prognostic classification, response evaluation through the quantification of minimal residual disease, and the launch of research on targeted therapies. Our knowledge of leukemogenesis, AML genetic diversity, gene-gene interactions, clonal evolution, and treatment response assessment has also greatly improved. New classifications based on chromosomal abnormalities and gene mutations are now integrated on a routine basis. These considerable efforts contributed to the discovery and development of promising drugs which specifically target gene mutations, apoptotic pathways and cell surface antigens as well as reformulate classical cytotoxic agents. In less than 2 years, nine novels drugs have been approved for the treatment of AML patients, and many others are being intensively investigated, in particular immune therapies. There are now numerous clinical research opportunities offered to clinicians, thanks to these new treatment options. We are only at the start of a new era which should see major disruptions in the way we understand, treat, and monitor patients with AML.

TP53 in Myelodysplastic Syndromes

Simple Summary

The importance of gene variants in the prognosis of myelodysplastic syndromes (MDSs) has been repeatedly reported in recent years. Especially, TP53 mutations are independently associated with a higher risk category, resistance to conventional therapies, rapid transformation to leukemia, and a poor outcome. In the review, we discuss the features of monoallelic and biallelic TP53 mutations within MDS, the carcinogenic mechanisms, and the predictive value of TP53 variants in current standard treatments including hypomethylating agents, allogeneic hematopoietic stem cell transplantation, and lenalidomide, as well as the latest progress in TP53-targeted therapy strategies in MDS.

Abstract

Myelodysplastic syndromes (MDSs) are heterogeneous for their morphology, clinical characteristics, survival of patients, and evolution to acute myeloid leukemia. Different prognostic scoring systems including the International Prognostic Scoring System (IPSS), the Revised IPSS, the WHO Typed Prognostic Scoring System, and the Lower-Risk Prognostic Scoring System have been introduced for categorizing the highly variable clinical outcomes. However, not considered by current MDS prognosis classification systems, gene variants have been identified for their contribution to the clinical heterogeneity of the disease and their impact on the prognosis. Notably, TP53 mutation is independently associated with a higher risk category, resistance to conventional therapies, rapid transformation to leukemia, and a poor outcome. Herein, we discuss the features of monoallelic and biallelic TP53 mutations within MDS, their corresponding carcinogenic mechanisms, their predictive value in current standard treatments including hypomethylating agents, allogeneic hematopoietic stem cell transplantation, and lenalidomide, together with the latest progress in TP53-targeted therapy strategies, especially MDS clinical trial data.

TP53 in Acute Myeloid Leukemia: Molecular Aspects and Patterns of Mutation

Mutation of the tumor suppressor gene, TP53, is associated with abysmal survival outcomes in acute myeloid leukemia (AML). Although it is the most commonly mutated gene in cancer, its occurrence is observed in only 5–10% of de novo AML, and in 30% of therapy related AML (t-AML). TP53 mutation serves as a prognostic marker of poor response to standard-of-care chemotherapy, particularly in t-AML and AML with complex cytogenetics. In light of a poor response to traditional chemotherapy and only a modest improvement in outcome with hypomethylation-based interventions, allogenic stem cell transplant is routinely recommended in these cases, albeit with a response that is often short lived. Despite being frequently mutated across the cancer spectrum, progress and enthusiasm for the development of p53 targeted therapeutic interventions is lacking and to date there is no approved drug that mitigates the effects of TP53 mutation. There is a mounting body of evidence indicating that p53 mutants differ in functionality and form from typical AML cases and subsequently display inconsistent responses to therapy at the cellular level. Understanding this pathobiological activity is imperative to the development of effective therapeutic strategies. This review aims to provide a comprehensive understanding of the effects of TP53 on the hematopoietic system, to describe its varying degree of functionality in tumor suppression, and to illustrate the need for the adoption of personalized therapeutic strategies to target distinct classes of the p53 mutation in AML management.

Clinical Characteristics, Prognosis, and Treatment Strategies of TP53 Mutations in Myelodysplastic Syndromes

TP53 gene mutations are common in myelodysplastic syndromes (MDS). Previous studies have reported their detrimental effects on patient survival. However, current treatment strategies mainly based on hypomethylating agent therapy (HMA) and hematopoietic stem cell transplantation (HSCT) still leave a lot to be desired. And there is also a lack of studies on large sample with a view to the refinement of specific characteristics and disease progression. So we performed a meta-analysis including 20 studies compromising 5067 patients to assess the prognostic impact and clinical characteristics of TP53 mutations in MDS patients. The overall hazard ratio for overall survival (OS) was 2.14 (95% confidence interval 1.94-2.37, P < .00001) compared with patients with MDS without TP53 mutations. Lower progression-free survival and leukemia-free survival were associated with TP53 mutations. Subgroup analysis revealed that TP53 mutations were significantly associated with high levels of blast cells and karyotypic aberrations. And among Asian population, the adverse impact on OS of TP53 mutations seemed worse than those in Western countries. (HR 2.87 vs. 2.02, P = .01). In addition, TP53 mutations had no effect on response to HMA therapy, and HSCT improved OS in patients carrying TP53 mutations.

Personalized Medicine for TP53 Mutated Myelodysplastic Syndromes and Acute Myeloid Leukemia

Targeting TP53 mutated myelodysplastic syndromes and acute myeloid leukemia remains a significant unmet need. Recently, new drugs have attempted to improve the outcomes of this poor molecular subgroup. The aim of this article is to review all the current knowledge using active agents including hypomethylating agents with venetoclax, eprenetapopt or magrolimab. We include comprehensive analysis of clinical trials to date evaluating these drugs in TP53 myeloid neoplasms as well as discuss future novel combinations for consideration. Additionally, further understanding of the unique clinicopathologic components of TP53 mutant myeloid neoplasms versus wild-type is critical to guide future study. Importantly, the clinical trajectory of patients is uniquely tied with the clonal burden of TP53, which enables serial TP53 variant allele frequency analysis to be a critical early biomarker in investigational studies. Together, significant optimism is now possible for improving outcomes in this patient population.

Ribosomal proteins and human diseases: molecular mechanisms and targeted therapy

Ribosome biogenesis and protein synthesis are fundamental rate-limiting steps for cell growth and proliferation. The ribosomal proteins (RPs), comprising the structural parts of the ribosome, are essential for ribosome assembly and function. In addition to their canonical ribosomal functions, multiple RPs have extra-ribosomal functions including activation of p53-dependent or p53-independent pathways in response to stress, resulting in cell cycle arrest and apoptosis. Defects in ribosome biogenesis, translation, and the functions of individual RPs, including mutations in RPs have been linked to a diverse range of human congenital disorders termed ribosomopathies. Ribosomopathies are characterized by tissue-specific phenotypic abnormalities and higher cancer risk later in life. Recent discoveries of somatic mutations in RPs in multiple tumor types reinforce the connections between ribosomal defects and cancer. In this article, we review the most recent advances in understanding the molecular consequences of RP mutations and ribosomal defects in ribosomopathies and cancer. We particularly discuss the molecular basis of the transition from hypo- to hyper-proliferation in ribosomopathies with elevated cancer risk, a paradox termed "Dameshek's riddle." Furthermore, we review the current treatments for ribosomopathies and prospective therapies targeting ribosomal defects. We also highlight recent advances in ribosome stress-based cancer therapeutics. Importantly, insights into the mechanisms of resistance to therapies targeting ribosome biogenesis bring new perspectives into the molecular basis of cancer susceptibility in ribosomopathies and new clinical implications for cancer therapy.

Mutant p53-reactivating compound APR-246 synergizes with asparaginase in inducing growth suppression in acute lymphoblastic leukemia cells

Asparaginase depletes extracellular asparagine in the blood and is an important treatment for acute lymphoblastic leukemia (ALL) due to asparagine auxotrophy of ALL blasts. Unfortunately, resistance occurs and has been linked to expression of the enzyme asparagine synthetase (ASNS), which generates asparagine from intracellular sources. Although TP53 is the most frequently mutated gene in cancer overall, TP53 mutations are rare in ALL. However, TP53 mutation is associated with poor therapy response and occurs at higher frequency in relapsed ALL. The mutant p53-reactivating compound APR-246 (Eprenetapopt/PRIMA-1Met) is currently being tested in phase II and III clinical trials in several hematological malignancies with mutant TP53. Here we present CEllular Thermal Shift Assay (CETSA) data indicating that ASNS is a direct or indirect target of APR-246 via the active product methylene quinuclidinone (MQ). Furthermore, combination treatment with asparaginase and APR-246 resulted in synergistic growth suppression in ALL cell lines. Our results thus suggest a potential novel treatment strategy for ALL.

Baseline and serial molecular profiling predicts outcomes with hypomethylating agents in myelodysplastic syndromes

Hypomethylating agents (HMAs) are widely used in the treatment of myelodysplastic syndromes (MDSs), yet identifying those patients unlikely to benefit remains challenging. We assessed response and overall survival (OS) in 247 patients molecularly profiled by next-generation sequencing (NGS) before first-line HMA therapy, and a subset of 108 patients were sequenced serially during treatment. The most common mutations included TP53 (33.1%), ASXL1 (19%), TET2 (16.5%), DNMT3A (14.1%), and SRSF2 (12.1%). The overall response rate was 42.1%, with the composite TET2-mutant/ASXL1 wild-type genotype representing the strongest predictor of response (overall response rate, 62.1%; complete remission rate, 34.5%). The median OS for the cohort was 15 months, and the number of mutations detected by NGS (hazard ratio [HR], 1.22; P = .02), as well as mutations in TP53 (HR, 2.33; P = .001) and EZH2 (HR, 2.41; P = .04) were identified as independent covariates associated with inferior OS in multivariable analysis. Serial molecular profiling revealed that clearance of TP53 mutations during HMA therapy was associated with superior OS (HR, 0.28; P = .001) and improved outcome in patients proceeding to allogeneic hematopoietic cell transplantation. These data support baseline molecular profiling by NGS in MDS patients treated with HMAs and provide novel observations of sequential profiling during therapy that provide particular value in TP53-mutated disease.

Genomic context and TP53 allele frequency define clinical outcomes in TP53-mutated myelodysplastic syndromes

TP53 mutations are associated with adverse outcomes and shorter response to hypomethylating agents (HMAs) in myelodysplastic syndrome (MDS). Limited data have evaluated the impact of the type, number, and patterns of TP53 mutations in response outcomes and prognosis of MDS. We evaluated the clinicopathologic characteristics, outcomes, and response to therapy of 261 patients with MDS and TP53 mutations. Median age was 68 years (range, 18-80 years). A total of 217 patients (83%) had a complex karyotype. TP53 mutations were detected at a median variant allele frequency (VAF) of 0.39 (range, 0.01-0.94). TP53 deletion was associated with lower overall response rate (ORR) (odds ratio, 0.3; P = .021), and lower TP53 VAF correlated with higher ORR to HMAs. Increase in TP53 VAF at the time of transformation was observed in 13 patients (61%), and previously undetectable mutations were observed in 15 patients (65%). TP53 VAF was associated with worse prognosis (hazard ratio, 1.02 per 1% VAF increase; 95% confidence interval, 1.01-1.03; P < .001). Integration of TP53 VAF and karyotypic complexity identified prognostic subgroups within TP53-mutant MDS. We developed a multivariable model for overall survival that included the revised International Prognostic Scoring System (IPSS-R) categories and TP53 VAF. Total score for each patient was calculated as follows: VAF TP53 + 13 × IPSS-R blast score + 16 × IPSS-R cytogenetic score + 28 × IPSS-R hemoglobin score + 46 × IPSS-R platelet score. Use of this model identified 4 prognostic subgroups with median survival times of not reached, 42.2, 21.9, and 9.2 months. These data suggest that outcomes of patients with TP53-mutated MDS are heterogeneous and that transformation may be driven not only by TP53 but also by other factors.

Eprenetapopt (APR-246) and Azacitidine in TP53-Mutant Myelodysplastic Syndromes

PURPOSE

Approximately 20% of patients with TP53-mutant myelodysplastic syndromes (MDS) achieve complete remission (CR) with hypomethylating agents. Eprenetapopt (APR-246) is a novel, first-in-class, small molecule that restores wild-type p53 functions in TP53-mutant cells.

METHODS

This was a phase Ib/II study to determine the safety, recommended phase II dose, and efficacy of eprenetapopt administered in combination with azacitidine in patients with TP53-mutant MDS or acute myeloid leukemia (AML) with 20%-30% marrow blasts (ClinicalTrials.gov identifier: NCT03072043).

RESULTS

Fifty-five patients (40 MDS, 11 AML, and four MDS/myeloproliferative neoplasms) with at least one TP53 mutation were treated. The overall response rate was 71% with 44% achieving CR. Of patients with MDS, 73% (n = 29) responded with 50% (n = 20) achieving CR and 58% (23/40) a cytogenetic response. The overall response rate and CR rate for patients with AML was 64% (n = 7) and 36% (n = 4), respectively. Patients with only TP53 mutations by next-generation sequencing had higher rates of CR (69% v 25%; P = .006). Responding patients had significant reductions in TP53 variant allele frequency and p53 expression by immunohistochemistry, with 21 (38%) achieving complete molecular remission (variant allele frequency < 5%). Median overall survival was 10.8 months with significant improvement in responding versus nonresponding patients by landmark analysis (14.6 v 7.5 months; P = .0005). Overall, 19/55 (35%) patients underwent allogeneic hematopoietic stem-cell transplant, with a median overall survival of 14.7 months. Adverse events were similar to those reported for azacitidine or eprenetapopt monotherapy, with the most common grade ≥ 3 adverse events being febrile neutropenia (33%), leukopenia (29%), and neutropenia (29%).

CONCLUSION

Combination treatment with eprenetapopt and azacitidine is well-tolerated yielding high rates of clinical response and molecular remissions in patients with TP53-mutant MDS and oligoblastic AML.

Navigating Myelodysplastic and Myelodysplastic/Myeloproliferative Overlap Syndromes

Myelodysplastic syndromes (MDS) and MDS/myeloproliferative neoplasms (MPNs) are clonal diseases that differ in morphologic diagnostic criteria but share some common disease phenotypes that include cytopenias, propensity to acute myeloid leukemia evolution, and a substantially shortened patient survival. MDS/MPNs share many clinical and molecular features with MDS, including frequent mutations involving epigenetic modifier and/or spliceosome genes. Although the current 2016 World Health Organization classification incorporates some genetic features in its diagnostic criteria for MDS and MDS/MPNs, recent accumulation of data has underscored the importance of the mutation profiles on both disease classification and prognosis. Machine-learning algorithms have identified distinct molecular genetic signatures that help refine prognosis and notable associations of these genetic signatures with morphologic and clinical features. Combined geno-clinical models that incorporate mutation data seem to surpass the current prognostic schemes. Future MDS classification and prognostication schema will be based on the portfolio of genetic aberrations and traditional features, such as blast count and clinical factors. Arriving at these systems will require studies on large patient cohorts that incorporate advanced computational analysis. The current treatment algorithm in MDS is based on patient risk as derived from existing prognostic and disease classes. Luspatercept is newly approved for patients with MDS and ring sideroblasts who are transfusion dependent after erythropoietic-stimulating agent failure. Other agents that address red blood cell transfusion dependence in patients with lower-risk MDS and the failure of hypomethylating agents in higher-risk disease are in advanced testing. Finally, a plethora of novel targeted agents and immune checkpoint inhibitors are being evaluated in combination with a hypomethylating agent backbone to augment the depth and duration of response and, we hope, improve overall survival.

Eprenetapopt Plus Azacitidine in TP53-Mutated Myelodysplastic Syndromes and Acute Myeloid Leukemia: A Phase II Study by the Groupe Francophone des Myélodysplasies (GFM)

TP53-mutated (TP53m) myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) have very poor outcome irrespective of the treatment received, including 40% responses (20% complete remission [CR]) with azacitidine (AZA) alone, short response duration, and a median overall survival (OS) of approximately 6 months. Eprenetapopt (APR-246), a novel first-in-class drug, leads to p53 protein reconformation and reactivates its proapoptotic and cell-cycle arrest functions.

TP53 Mutations in Acute Myeloid Leukemia: Still a Daunting Challenge?

TP53 is a key tumor suppressor gene with protean functions associated with preservation of genomic balance, including regulation of cellular senescence, apoptotic pathways, metabolism functions, and DNA repair. The vast majority of de novo acute myeloid leukemia (AML) present unaltered TP53 alleles. However, TP53 mutations are frequently detected in AML related to an increased genomic instability, such as therapy‐related (t-AML) or AML with myelodysplasia-related changes. Of note, TP53 mutations are associated with complex cytogenetic abnormalities, advanced age, chemoresistance, and poor outcomes. Recent breakthroughs in AML research and the development of targeted drugs directed at specific mutations have led to an explosion of novel treatments with different mechanisms. However, optimal treatment strategy for patients harboring TP53 mutations remains a critical area of unmet need. In this review, we focus on the incidence and clinical significance of TP53 mutations in de novo and t-AML. The influence of these alterations on response and clinical outcomes as well as the current and future therapeutic perspectives for this hardly treatable setting are discussed.

A thiol-bound drug reservoir enhances APR-246-induced mutant p53 tumor cell death

The tumor suppressor gene TP53 is the most frequently mutated gene in cancer. The compound APR-246 (PRIMA-1Met/Eprenetapopt) is converted to methylene quinuclidinone (MQ) that targets mutant p53 protein and perturbs cellular antioxidant balance. APR-246 is currently tested in a phase III clinical trial in myelodysplastic syndrome (MDS). By in vitro, ex vivo, and in vivo models, we show that combined treatment with APR-246 and inhibitors of efflux pump MRP1/ABCC1 results in synergistic tumor cell death, which is more pronounced in TP53 mutant cells. This is associated with altered cellular thiol status and increased intracellular glutathione-conjugated MQ (GS-MQ). Due to the reversibility of MQ conjugation, GS-MQ forms an intracellular drug reservoir that increases availability of MQ for targeting mutant p53. Our study shows that redox homeostasis is a critical determinant of the response to mutant p53-targeted cancer therapy.

Decitabine treatment in 311 patients with acute myeloid leukemia: outcome and impact of TP53 mutations - a registry based analysis

We performed a registry-based analysis of 311 AML patients treated with decitabine in a standard of care setting to assess response and survival data with a distinct focus on the impact of the TP53 mutation status. Median age was 73 years. 172 patients received decitabine first-line and 139 in r/r disease. The ORR (whole cohort) was 30% with a median overall survival of 4.7 months. First-line patients achieved better responses than r/r-patients (ORR: 38% vs. 21%) resulting in a median OS of 5.8 months vs. 3.9 months. NGS based mutation analysis was performed in 180 patients. 20 patients (11%) harbored a TP53 mutation. Response rates and survival did not differ significantly between TP53 mutated patients and wild-type patients. This analysis of a large cohort of AML patients provides response rates and OS data after decitabine treatment. Interestingly, outcome was not negatively influenced by a TP53 mutation.

Chronic myelomonocytic leukemia - a review

INTRODUCTION

Chronic myelomonocytic leukemia (CMML) is a clonal myeloid neoplasm, denoted by overlapping myelodysplastic and myeloproliferative features, with poor overall survival and high transformation rate to acute myeloid leukemia.

AREAS COVERED

This review, following a thorough Medline search of pertinent published literature, discusses the diagnostic criteria, the pathogenesis, and the complex genetic landscape of the disease. Prognostication, response criteria, therapeutic management of patients, efficacy of established and novel treatment modalities are thoroughly reviewed.

EXPERT OPINION

Cytogenetic abnormalities and mutations in genes involved in epigenetic and transcriptional regulation, and cell-signaling are abundant in CMML and implicated in its complex pathogenesis. As presence of these mutations carry a prognostic impact, they are increasingly incorporated in risk-stratification schemes. Novel response criteria have been proposed, considering the unique features of the disease. Although allogeneic hematopoietic stem cell transplantation remains the only treatment with curative intent, it is reserved for a minority of patients; therefore, there is an unmet need for optimizing treatment modalities, such as hypomethylating agents, and introducing novel agents, which could substantially improve survival and quality of life of CMML patients. Clinical trials dedicated specifically to CMML are needed to explore the efficacy and safety of novel treatment modalities.

Myelodysplastic syndromes: 2021 update on diagnosis, risk stratification and management

DISEASE OVERVIEW

The myelodysplastic syndromes (MDS) are a very heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to acute myelogenous leukemia (AML). Myelodysplastic syndromes occur more frequently in older males and in individuals with prior exposure to cytotoxic therapy.

DIAGNOSIS

Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy. Information obtained from additional studies such as karyotype, flow cytometry and molecular genetics is usually complementary and may help refine diagnosis.

RISK-STRATIFICATION

Prognosis of patients with MDS can be calculated using a number of scoring systems. In general, all these scoring systems include analysis of peripheral cytopenias, percentage of blasts in the bone marrow and cytogenetic characteristics. The most commonly accepted system is the Revised International Prognostic Scoring System (IPSS-R). Somatic mutations can help define prognosis and therapy.

RISK-ADAPTED THERAPY

Therapy is selected based on risk, transfusion needs, percent of bone marrow blasts, cytogenetic and mutational profiles, comorbidities, potential for allogeneic stem cell transplantation (alloSCT) and prior exposure to hypomethylating agents (HMA). Goals of therapy are different in lower-risk patients than in higher-risk individuals and in those with HMA failure. In lower-risk MDS, the goal is to decrease transfusion needs and transformation to higher risk disease or AML, as well as to improve survival. In higher-risk disease, the goal is to prolong survival. In 2020, we witnessed an explosion of new agents and investigational approaches. Current available therapies include growth factor support, lenalidomide, HMAs, intensive chemotherapy and alloSCT. Novel therapeutics approved in 2020 are luspatercept and the oral HMA ASTX727. At the present time, there are no approved interventions for patients with progressive or refractory disease particularly after HMA-based therapy. Options include participation in a clinical trial, cytarabine-based therapy or alloSCT.

Impact of TP53 mutations in acute myeloid leukemia patients treated with azacitidine

Hypomethylating agents are a classical frontline low-intensity therapy for older patients with acute myeloid leukemia. Recently, TP53 gene mutations have been described as a potential predictive biomarker of better outcome in patients treated with a ten-day decitabine regimen., However, functional characteristics of TP53 mutant are heterogeneous, as reflected in multiple functional TP53 classifications and their impact in patients treated with azacitidine is less clear. We analyzed the therapeutic course and outcome of 279 patients treated with azacitidine between 2007 and 2016, prospectively enrolled in our regional healthcare network. By screening 224 of them, we detected TP53 mutations in 55 patients (24.6%), including 53 patients (96.4%) harboring high-risk cytogenetics. The identification of any TP53 mutation was associated with worse overall survival but not with response to azacitidine in the whole cohort and in the subgroup of patients with adverse karyotype. Stratification of patients according to three recent validated functional classifications did not allow the identification of TP53 mutated patients who could benefit from azacitidine. Systematic TP53 mutant classification will deserve further exploration in the setting of patients treated with conventional therapy and in the emerging field of therapies targeting TP53 pathway.

Prognostic significance of serial molecular annotation in myelodysplastic syndromes (MDS) and secondary acute myeloid leukemia (sAML)

The implementation of next-generation sequencing (NGS) has influenced diagnostic, prognostic, and therapeutic decisions in myeloid malignancies. However, the clinical relevance of serial molecular annotation in patients with myelodysplastic syndrome (MDS) undergoing active treatment is unknown. MDS or secondary acute myeloid leukemia (sAML) patients who had at least two NGS assessments were identified. Outcomes according to mutation clearance (NGS-) on serial assessment were investigated. Univariate and multivariate Cox regression models were used to evaluate the prognostic impact of NGS trajectory on overall survival (OS). A total of 157 patients (MDS [n = 95]; sAML [n = 52]; CMML [n = 10]) were identified, with 93% of patients receiving treatment between NGS assessments. Magnitude of VAF delta from baseline was significantly associated with quality of response to treatment. Patients achieving NGS- had significantly improved OS compared to patients with mutation persistence (median OS not reached vs. 18.5 months; P = 0.002), which was confirmed in multivariate analysis (HR,0.14; 95%CI = 0.03-0.56; P = 0.0064). Serial TP53 VAF evaluation predicts outcomes with TP53 clearance representing an independent covariate for superior OS (HR,0.22; 95%CI = 0.05-0.99; P = 0.048). Collectively, our study highlights the clinical value of serial NGS during treatment and warrants prospective validation of NGS negativity as a biomarker for treatment outcome.

Role Of TP53 mutations in predicting the clinical efficacy of hypomethylating therapy in patients with myelodysplastic syndrome and related neoplasms: a systematic review and meta-analysis

Hypomethylating agents (HMAs) are now a major treatment option for myelodysplastic syndrome (MDS) and related neoplasms, but 50% of patients still do not respond and realize poor outcomes. Mutational predictors of treatment efficacy attract continuous attention. Whether TP53 mutations can be used as predictors of HMA effectiveness has caused heated debate. Therefore, we performed a meta-analysis to investigate the predictive value of TP53 mutations to outcomes of HMA therapy in patients with MDS and related neoplasms. We systematically searched PubMed, Embase, the Cochrane Library, and the WanFang databases (published deadline: September 12, 2019). The primary endpoints were overall response rate (ORR) and overall survival (OS). Odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CI) were pooled to estimate the association between TP53 mutations and the clinical efficacy of HMAs. Four hundred fifteen papers were found, and 22 papers were included in this meta-analysis (N = 2020 participants). The results showed that the presence of TP53 mutation predicted an increased overall response rate with HMA treatment in the subsets that restricted patients in de novo disease, MDS by WHO (World Health Organization) criteria, or NGS (next-generation sequence) group (P = 0.005, P = 0.003, P = 0.0005, respectively). However, TP53 mutations remained poor factors for OS (P < 0.00001). Collectively, in HMA therapy, TP53 mutations can predict better ORR when setting more refined subgroups, but TP53 mutations still strongly correlated with poor survival in hypomethylating therapy.

Monosomal karyotype and chromosome 17p loss or TP53 mutations in decitabine-treated patients with acute myeloid leukemia

TP53 aberrations reportedly predict favorable responses to decitabine (DAC) in acute myeloid leukemia (AML). We evaluated clinical features and outcomes associated with chromosome 17p loss or TP53 gene mutations in older, unfit DAC-treated AML patients in a phase II trial. Of 178 patients, 25 had loss of 17p in metaphase cytogenetics; 24 of these had a complex (CK+) and 21 a monosomal karyotype (MK+). In analyses in all patients and restricted to CK+ and MK+ patients, 17p loss tended to associate with higher rates of complete remission (CR), partial remission (PR), or antileukemic effect (ALE). Despite favorable response rates, there was no significant OS difference between patients with or without loss of 17p in the entire cohort or in the CK+ and MK+ cohort. TP53 mutations were identified in eight of 45 patients with material available. Five of the eight TP53-mutated patients had 17p loss. TP53-mutated patients had similar rates of CR/PR/ALE but shorter OS than those with TP53 wild type (P = 0.036). Moreover, patients with a subclone based on mutation data had shorter OS than those without (P = 0.05); only one patient with TP53-mutated AML had a subclone. In conclusion, 17p loss conferred a favorable impact on response rates, even among CK+ and MK+ patients that however could not be maintained. The effect of TP53 mutations appeared to be different; however, patient numbers were low. Future research needs to further dissect the impact of the various TP53 aberrations in HMA-based combination therapies. The limited duration of favorable responses to HMA treatment in adverse-risk genetics AML should prompt physicians to advance allografting for eligible patients in a timely fashion.

The Evolving Landscape of Myelodysplastic Syndrome Prognostication

Myelodysplastic syndromes (MDSs) are potentially devastating monoclonal deviations of hematopoiesis that lead to bone marrow dysplasia and variable cytopenias. Predicting severity of disease progression and likelihood to undergo acute myeloid leukemia transformation is the basis of treatment strategy. Some patients belong to a low-risk cohort best managed with conservative supportive care, whereas others are included in a high-risk cohort that requires decisive therapy with hematopoietic cell transplantation or hypomethylating agent administration. Risk scoring systems for MDS prognostication were traditionally based on karyotype characteristics and clinical factors readily available from chart review, and validation was typically conducted on de novo MDS patients. However, retrospective analysis found a large subset of patients incorrectly risk-stratified. In this review, the most commonly used scoring systems are evaluated, and pitfalls therein are identified. Emerging technologies such as personal genomics and machine learning are then explored for efficacy in MDS risk modeling. Barriers to clinical adoption of artificial intelligence-derived models are discussed, with focus on approaches meant to increase model interpretability and clinical relevance. Finally, a guiding set of recommendations is proposed for best designing an accurate and universally applicable prognostic model for MDS, which is supported by more than 20 years of observation of traditional scoring system performance, as well as modern efforts in creating hybrid genomic-clinical scoring systems.

TP53 in Myelodysplastic Syndromes: Recent Biological and Clinical Findings

TP53 dysregulation plays a pivotal role in the molecular pathogenesis of myelodysplastic syndromes (MDS), identifying a subgroup of patients with peculiar features. In this review we report the recent biological and clinical findings of TP53-mutated MDS, focusing on the molecular pathways activation and on its impact on the cellular physiology. In MDS, TP53 mutational status is deeply associated with del(5q) syndrome and its dysregulation impacts on cell cycle, DNA repair and apoptosis inducing chromosomal instability and the clonal evolution of disease. TP53 defects influence adversely the MDS clinical outcome and the treatment response rate, thus new therapeutic approaches are being developed for these patients. TP53 allelic state characterization and the mutational burden evaluation can therefore predict prognosis and identify the subgroup of patients eligible for targeted therapy. For these reasons, in the era of precision medicine, the MDS diagnostic workup cannot do without the complete assessment of TP53 mutational profile.

Prognostic value of indoleamine 2,3 dioxygenase in patients with higher-risk myelodysplastic syndromes treated with azacytidine

Hypomethylating agents (HMAs) are widely used in patients with higher-risk myelodysplastic syndromes (MDS) not eligible for stem cell transplantation; however, the response rate is <50%. Reliable predictors of response are still missing, and it is a major challenge to develop new treatment strategies. One current approach is the combination of azacytidine (AZA) with checkpoint inhibitors; however, the potential benefit of targeting the immunomodulator indoleamine-2,3-dioxygenase (IDO-1) has not yet been evaluated. We observed moderate to strong IDO-1 expression in 37% of patients with high-risk MDS. IDO-1 positivity was predictive of treatment failure and shorter overall survival. Moreover, IDO-1 positivity correlated inversely with the number of infiltrating CD8⁺ T cells, and IDO-1+ patients failed to show an increase in CD8⁺ T cells under AZA treatment. In vitro experiments confirmed tryptophan catabolism and depletion of CD8⁺ T cells in IDO-1+ MDS, suggesting that IDO-1 expression induces an immunosuppressive microenvironment in MDS, thereby leading to treatment failure under AZA treatment. In conclusion, IDO-1 is expressed in more than one-third of patients with higher-risk MDS, and is predictive of treatment failure and shorter overall survival. Therefore, IDO-1 is emerging as a promising predictor and therapeutic target, especially for combination therapies with HMAs or checkpoint inhibitors.