Clinical implications of TP53 mutations in myelodysplastic syndromes treated with hypomethylating agents

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.

Advances in the management of higher-risk myelodysplastic syndromes: future prospects

Higher-risk myelodysplastic syndromes (HR-MDS) are defined using a number of prognostic scoring systems that include the degree of cytopenias, percentage of blasts, cytogenetic alterations, and more recently genomic data. HR-MDS encompasses characteristics such as progressive cytopenias, increased bone marrow blasts, unfavorable cytogenetics, and an adverse mutational profile. Survival is generally poor, and patients require therapy to improve outcomes. Hypomethylating agents (HMAs), such as azacitidine, decitabine, and more recently, oral decitabine/cedazuridine, are the only approved therapies for HR-MDS. These are often continued until loss of response, progression, or unacceptable toxicity. Combinations including an HMA plus other drugs have been investigated but have not demonstrated better outcomes compared to single-agent HMA. Moreover, in a disease of high genomic complexity such as HR-MDS, therapy targeting specific genomic abnormalities is of interest. This review will examine the biological underpinnings of HR-MDS, its therapeutic landscape in the frontline and relapsed settings, as well as the impact of hematopoietic stem cell transplantation, the only known curative intervention for this disease.

TP53-mutated acute myeloid leukemia and myelodysplastic syndrome: biology, treatment challenges, and upcoming approaches

Improved understanding of TP53 biology and the clinicopathological features of TP53-mutated myeloid neoplasms has led to the recognition of TP53-mutated acute myeloid leukemia/myelodysplastic syndrome (TP53m AML/MDS) as a unique entity, characterized by dismal outcomes following conventional therapies. Several clinical trials have investigated combinations of emerging therapies for these patients with the poorest molecular prognosis among myeloid neoplasms. Although some emerging therapies have shown improvement in overall response rates, this has not translated into better overall survival, hence the notion that p53 remains an elusive target. New therapeutic strategies, including novel targeted therapies, immune checkpoint inhibitors, and monoclonal antibodies, represent a shift away from cytotoxic and hypomethylating-based therapies, towards approaches combining non-immune and novel immune therapeutic strategies. The triple combination of azacitidine and venetoclax with either magrolimab or eprenetapopt have demonstrated safety in early trials, with phase III trials currently underway, and promising interim clinical results. This review compiles background on TP53 biology, available and emerging therapies along with their mechanisms of action for the TP53m disease entity, current treatment challenges, and recently published data and status of ongoing clinical trials for TP53m AML/MDS.

Oral decitabine plus cedazuridine and venetoclax in patients with higher-risk myelodysplastic syndromes or chronic myelomonocytic leukaemia: a single-centre, phase 1/2 study

BACKGROUND

Hypomethylating agents are approved in higher-riskmyelodysplastic syndromes. The combination of a hypomethylating agent with venetoclax is standard of care in acute myeloid leukaemia. We investigated the safety and activity of the first totally oral combination of decitabine plus cedazuridine and venetoclax in patients with higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia.

METHODS

We did a single-centre, dose-escalation and dose-expansion, phase 1/2, clinical trial. Patients with treatment-naive higher-risk-myelodysplastic syndromes or chronic myelomonocytic leukaemia (risk level categorised as intermediate-2 or higher by the International Prognostic Scoring System) with excess blasts (>5%). Treatment consisted of oral decitabine 35 mg plus cedazuridine 100 mg on days 1-5 and venetoclax (variable doses of 100-400 mg, day 1 to 14, 28-day cycle). The primary outcomes were safety for the phase 1 part and the overall response for the phase 2 part of the study. The trial is ongoing and this analysis was not prespecified. This study is registered with ClinicalTrials.gov, NCT04655755, and is currently enrolling participants.

FINDINGS

Between Jan 21, 2021, and Jan 20, 2023, we enrolled 39 patients (nine in phase 1 and 30 in phase 2). The median age was 71 years (range 27-94), 28 (72%) patients were male, and 11 (28%) were female. The maximum tolerated dose was not reached, and the recommended phase 2 dose was established as oral decitabine 35 mg plus cedazuridine 100 mg for 5 days and venetoclax (400 mg) for 14 days. The most common grade 3-4 adverse events were thrombocytopenia (33 [85%] of 39), neutropenia (29 [74%]), and febrile neutropenia (eight [21%]). Four non-treatment-related deaths occurred on the study drugs due to sepsis (n=2), lung infection (n=1), and undetermined cause (n=1). The median follow-up time was 10·8 months (IQR 5·6-16·4). The overall response rate was 95% (95% CI 83-99; 37/39). 19 (49%) patients proceeded to hematopoietic stem-cell transplantation.

INTERPRETATION

This early analysis suggests that the combination of oral decitabine plus cedazuridine with venetoclax for higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia is safe in most patients, with encouraging activity. Longer follow-up will be needed to confirm these data.

FUNDING

MD Anderson Cancer Center, MDS/AML Moon Shot, Genentech/AbbVie, and Astex Pharmaceuticals.

Phase 1/2 study of CPX-351 for patients with Int-2 or high risk International Prognostic Scoring System myelodysplastic syndromes and chronic myelomonocytic leukaemia after failure to hypomethylating agents

Failure after hypomethylating agents (HMAs) is associated with dismal outcomes in higher risk myelodysplastic syndromes (HR-MDS) or chronic myelomonocytic leukaemia (CMML). We aimed to evaluate the safety and preliminary activity of lower doses of CPX-351, a liposomal encapsulation of cytarabine and daunorubicin, in a single-centre, phase 1/2 study for patients with HR-MDS or CMML after HMA failure. Four doses of CPX-351 (10, 25, 50 and 75 units/m2 ) administered on Days 1, 3 and 5 of induction and Days 1 and 3 of consolidation were evaluated. Between June 2019 and June 2023, 25 patients were enrolled (phase 1: n = 15; phase 2: n = 10) including 19 (76%) with HR-MDS and 6 (24%) with CMML. Most common grade 3-4 non-haematological treatment-emergent adverse events were febrile neutropenia (n = 12, 48%) and lung infection (n = 5, 20%). Three patients (age >75) experienced cardiac toxicity at the 75 units/m2 dose. Further enrolment continued at 50 units/m2 . Four- and 8-week mortality were 0% and 8% respectively. The overall response rate was 56% with median relapse-free and overall survivals of 9.2 (95% CI 3.2-15.1 months) and 8.7 months (95% CI 1.8-15.6 months) respectively. These data suggest that lower doses of CPX-351 are safe. Further studies are needed to evaluate its activity.

Beyond the horizon: emerging therapeutic approaches in myelodysplastic neoplasms

Management of myelodysplastic neoplasms (MDS) requires a personalized approach, with a focus on improving quality of life and extending lifespan. The International Prognostic Scoring System-Revised and the molecular International Prognostic Scoring System are key tools for risk stratification and management of MDS. They provide a framework for predicting survival and the risk of transformation to acute myeloid leukemia. However, a major challenge in MDS management remains the limited therapeutic options available, especially after the failure of first-line therapies. In lower-risk MDS, the failure of erythropoietin-stimulating agents often leaves few alternatives, although in higher-risk MDS, the prognosis after hypomethylating agent failure is dismal. This highlights the urgent need for novel, more personalized therapeutic approaches. In this review, we discuss emerging novel therapeutic approaches in the treatment of MDS. Several new therapeutic targets are currently being evaluated, offering hope for improved management of MDS in the future.

Fifth Edition of the World Health Classification of Tumors of the Hematopoietic and Lymphoid Tissue: Myeloid Neoplasms

In this manuscript, we review myeloid neoplasms in the fifth edition of the World Health Organization classification of hematolymphoid tumors (WHO-HEM5), focusing on changes from the revised fourth edition (WHO-HEM4R). Disease types and subtypes have expanded compared with WHO-HEM4R, mainly because of the expansion in genomic knowledge of these diseases. The revised classification is based on a multidisciplinary approach including input from a large body of pathologists, clinicians, and geneticists. The revised classification follows a hierarchical structure allowing usage of family (class)-level definitions where the defining diagnostic criteria are partially met or a complete investigational workup has not been possible. Overall, the WHO-HEM5 revisions to the classification of myeloid neoplasms include major updates and revisions with increased emphasis on genetic and molecular drivers of disease. The most notable changes have been applied to the sections of acute myeloid leukemia and myelodysplastic neoplasms (previously referred to as myelodysplastic syndrome) with incorporation of novel, disease-defining genetic changes. In this review we focus on highlighting the updates in the classification of myeloid neoplasms, providing a comparison with WHO-HEM4R, and offering guidance on how the new classification can be applied to the diagnosis of myeloid neoplasms in routine practice.

Predictive value of DNA methylation patterns in AML patients treated with an azacytidine containing induction regimen

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous disease with a poor prognosis. Dysregulation of the epigenetic machinery is a significant contributor to disease development. Some AML patients benefit from treatment with hypomethylating agents (HMAs), but no predictive biomarkers for therapy response exist. Here, we investigated whether unbiased genome-wide assessment of pre-treatment DNA-methylation profiles in AML bone marrow blasts can help to identify patients who will achieve a remission after an azacytidine-containing induction regimen.

RESULTS

A total of n = 155 patients with newly diagnosed AML treated in the AMLSG 12-09 trial were randomly assigned to a screening and a refinement and validation cohort. The cohorts were divided according to azacytidine-containing induction regimens and response status. Methylation status was assessed for 664,227 500-bp-regions using methyl-CpG immunoprecipitation-seq, resulting in 1755 differentially methylated regions (DMRs). Top regions were distilled and included genes such as WNT10A and GATA3. 80% of regions identified as a hit were represented on HumanMethlyation 450k Bead Chips. Quantitative methylation analysis confirmed 90% of these regions (36 of 40 DMRs). A classifier was trained using penalized logistic regression and fivefold cross validation containing 17 CpGs. Validation based on mass spectra generated by MALDI-TOF failed (AUC 0.59). However, discriminative ability was maintained by adding neighboring CpGs. A recomposed classifier with 12 CpGs resulted in an AUC of 0.77. When evaluated in the non-azacytidine containing group, the AUC was 0.76.

CONCLUSIONS

Our analysis evaluated the value of a whole genome methyl-CpG screening assay for the identification of informative methylation changes. We also compared the informative content and discriminatory power of regions and single CpGs for predicting response to therapy. The relevance of the identified DMRs is supported by their association with key regulatory processes of oncogenic transformation and support the idea of relevant DMRs being enriched at distinct loci rather than evenly distribution across the genome. Predictive response to therapy could be established but lacked specificity for treatment with azacytidine. Our results suggest that a predictive epigenotype carries its methylation information at a complex, genome-wide level, that is confined to regions, rather than to single CpGs. With increasing application of combinatorial regimens, response prediction may become even more complicated.

Clinical and genetic features of Japanese cases of MDS associated with VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a new disease entity with autoinflammatory disorders (AID) driven by somatic variants in UBA1 that frequently co-exists with myelodysplastic syndromes (MDS). Clinicopathological and molecular features of Japanese cases with VEXAS-associated MDS remain elusive. We previously reported high prevalence of UBA1 variants in Japanese patients with relapsing polychondritis, in which 5 cases co-occurred with MDS. Here, we report clinicopathological and variant profiles of these 5 cases and 2 additional cases of MDS associated with VEXAS syndrome. Clinical characteristics of these cases included high prevalence of macrocytic anemia with marked cytoplasmic vacuoles in myeloid/erythroid precursors and low bone marrow (BM) blast percentages. All cases were classified as low or very low risk by the revised international prognostic scoring system (IPSS-R). Notably, 4 out of 7 cases showed significant improvement of anemia by treatment with prednisolone (PSL) or cyclosporin A (CsA), suggesting that an underlying inflammatory milieu induced by VEXAS syndrome may aggravate macrocytic anemia in VEXAS-associated MDS. Targeted deep sequencing of blood samples suggested that MDS associated with VEXAS syndrome tends to involve a smaller number of genes and lower risk genetic lesions than classical MDS.

DNA methyltransferase inhibitor exposure-response: Challenges and opportunities

Although DNA methyltransferase inhibitors (DNMTis), such as azacitidine and decitabine, are used extensively in the treatment of myelodysplastic syndromes and acute myeloid leukemia, there remain unanswered questions about DNMTi's mechanism of action and predictors of clinical response. Because patients often remain on single-agent DNMTis or DNMTi-containing regimens for several months before knowing whether clinical benefit can be achieved, the development and clinical validation of response-predictive biomarkers represents an important unmet need in oncology. In this review, we will summarize the clinical studies that led to the approval of azacitidine and decitabine, as well as the real-world experience with these drugs. We will then focus on biomarker development for DNMTis-specifically, efforts at determining exposure-response relationships and challenges that remain impacting the broader clinical translation of these methods. We will highlight recent progress in liquid-chromatography tandem mass spectrometry technology that has allowed for the simultaneous measurement of decitabine genomic incorporation and global DNA methylation, which has significant potential as a mechanism-of-action based biomarker in patients on DNMTis. Last, we will cover important research questions that need to be addressed in order to optimize this potential biomarker for clinical use.

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.

Evaluation of new IPSS-Molecular model and comparison of different prognostic systems in patients with myelodysplastic syndrome

A risk-adapted treatment strategy is of crucial importance in patients with myelodysplastic syndromes (MDS). Previous risk prognostic scoring systems did not integrate molecular abnormalities. The new IPSS-Molecular (IPSS-M) model, combing genomic profiling with hematologic and cytogenetic parameters, was recently developed to evaluate the associations with leukemia-free survival (LFS), leukemic transformation, and overall survival (OS). However, it has not yet been widely validated in clinics. This study aims to further validate the prognostic power of IPSS-M based on real-world data and to compare the prognostic value of different scoring systems in patients with MDS. IPSS-M Web calculator was used to calculate a tailored IPSS-M score of the enrolled patient (N = 255), and the risk category was defined correspondingly. We next compared the IPSS-M prognostic power to that of IPSS, IPSS-R, and WPSS. We found that IPSS-M risk classification was statistically significant for 3-year OS and LFS. Compared with other tools, IPSS-M was superior in sensitivity and accuracy for 3-year OS and LFS. The mapping C-index between IPSS-R and IPSS-M categories resulted in improved discrimination across the OS, but not LFS and leukemic transformation. The result of different treatment options indicated that allogeneic hematopoietic stem cell transplantation (allo-HSCT) can result in a better OS than those without allo-HSCT. In conclusion, IPSS-M was a valuable tool for risk stratification compared with other risk prognostic scoring systems. However, more studies should be conducted to explore the appropriate treatment options for different groups stratified by IPSS-M.

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.

Magrolimab in Combination With Azacitidine in Patients With Higher-Risk Myelodysplastic Syndromes: Final Results of a Phase Ib Study

PURPOSE

Magrolimab is a monoclonal antibody that blocks cluster of differentiation 47, a don't-eat-me signal overexpressed on cancer cells. Cluster of differentiation 47 blockade by magrolimab promotes macrophage-mediated phagocytosis of tumor cells and is synergistic with azacitidine, which increases expression of eat-me signals. We report final phase Ib data in patients with untreated higher-risk myelodysplastic syndromes (MDS) treated with magrolimab and azacitidine (ClinicalTrials.gov identifier: NCT03248479).

PATIENTS AND METHODS

Patients with previously untreated Revised International Prognostic Scoring System intermediate-/high-/very high-risk MDS received magrolimab intravenously as a priming dose (1 mg/kg) followed by ramp-up to a 30 mg/kg once-weekly or once-every-2-week maintenance dose. Azacitidine 75 mg/m2 was administered intravenously/subcutaneously once daily on days 1-7 of each 28-day cycle. Primary end points were safety/tolerability and complete remission (CR) rate.

RESULTS

Ninety-five patients were treated. Revised International Prognostic Scoring System risk was intermediate/high/very high in 27%, 52%, and 21%, respectively. Fifty-nine (62%) had poor-risk cytogenetics and 25 (26%) had TP53 mutation. The most common treatment-emergent adverse effects included constipation (68%), thrombocytopenia (55%), and anemia (52%). Median hemoglobin change from baseline to first postdose assessment was -0.7 g/dL (range, -3.1 to +2.4). CR rate and overall response rate were 33% and 75%, respectively. Median time to response, duration of CR, duration of overall response, and progression-free survival were 1.9, 11.1, 9.8, and 11.6 months, respectively. Median overall survival (OS) was not reached with 17.1-month follow-up. In TP53-mutant patients, 40% achieved CR with median OS of 16.3 months. Thirty-four patients (36%) had allogeneic stem-cell transplant with 77% 2-year OS.

CONCLUSION

Magrolimab + azacitidine was well tolerated with promising efficacy in patients with untreated higher-risk MDS, including those with TP53 mutations. A phase III trial of magrolimab/placebo + azacitidine is ongoing (ClinicalTrials.gov identifier: NCT04313881 [ENHANCE]).

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.

TP53 mutations are associated with increased infections and reduced hematopoietic cell transplantation rates in myelodysplastic syndrome and acute myeloid leukemia

BACKGROUND

Although allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy for patients with poor-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), only a minority of these patients undergo HCT. TP53-mutated (TP53^MUT) MDS/AML is particularly high risk, yet fewer TP53^MUT patients undergo HCT than other poor-risk TP53-wild type (TP53^WT) patients.

OBJECTIVE

We hypothesized that TP53^MUT MDS/AML patients have unique risk factors affecting rates of HCT, and therefore investigated phenotypic changes that may prevent patients with TP53^MUT MDS/AML from receiving HCT.

STUDY DESIGN

This study was a single center retrospective analysis of outcomes for adults with newly diagnosed MDS or AML (n=352). HLA typing was used as a surrogate for physician "intent to transplant." Multivariable logistic regression models were used to estimate odds ratios (OR) for factors associated with HLA typing, HCT, and pre-transplant infections. Multivariable Cox proportional hazards models were used to create predicted survival curves for patients with and without TP53 mutations.

RESULTS

Overall significantly fewer TP53^MUT patients underwent HCT compared to TP53^WT patients (19% versus 31%, p=0.028). Development of an infection was significantly associated with decreased odds of HCT (OR=0.42, 95% CI: 0.19-0.90) and worse overall survival (HR=1.46, 95% CI: 1.09-1.96) in multivariable analyses. TP53^MUT disease was independently associated with increased odds of developing an infection (OR 2.18, 95% CI: 1.21-3.93), bacterial pneumonia (OR 1.83, 95% CI: 1.00-3.33), and invasive fungal infection (OR 2.64, 95% CI: 1.34-5.22) prior to HCT. Infections were the cause of death in significantly more patients with TP53^MUT disease (38% vs 19%, p=0.005).

CONCLUSIONS

With substantially more infections and decreased HCT rates in patients with TP53 mutations, this raises the possibility that phenotypic changes occurring in TP53^MUT disease may affect infection susceptibility in this population and drastically impact clinical outcomes.

MDM2 antagonist improves therapeutic activity of azacitidine in myelodysplastic syndromes and chronic myelomonocytic leukemia

Failure of hypomethylation agent (HMA) treatments is an important issue in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). Recent studies indicated that function of wildtype TP53 positively impacts outcome of HMA treatments. We investigated the combination of the HMA azacitidine (AZA) with DS-3032b and DS-5272, novel antagonists of the TP53 negative regulator MDM2, in cellular and animal models of MDS and CMML. In TP53 wildtype myeloid cell line, combinational effects of DS-3032b or DS-5272 with AZA were observed. In Tet2-knockout mouse model of MDS and CMML, DS-5272 and AZA combination ameliorated disease-like phenotype. RNA-Seq analysis in mouse bone marrow hematopoietic stem and progenitors indicated that DS-5272 and AZA combination caused down-regulation of leukemia stem cell marker genes and activation of pathways of TP53 function and stability. These findings demonstrate that combining an MDM2 antagonist with AZA has potential to improve AZA treatment in TP53 wildtype MDS and CMML.

Small molecule MMRi62 targets MDM4 for degradation and induces leukemic cell apoptosis regardless of p53 status

MDM2 and MDM4 proteins are key negative regulators of tumor suppressor p53. MDM2 and MDM4 interact via their RING domains and form a heterodimer polyubiquitin E3 ligase essential for p53 degradation. MDM4 also forms heterodimer E3 ligases with MDM2 isoforms that lack p53-binding domains, which regulate p53 and MDM4 stability. We are working to identify small-molecule inhibitors targeting the RING domain of MDM2-MDM4 (MMRi) that can inactivate the total oncogenic activity of MDM2-MDM4 heterodimers. Here, we describe the identification and characterization of MMRi62 as an MDM4-degrader and apoptosis inducer in leukemia cells. Biochemically, in our experiments, MMRi62 bound to preformed RING domain heterodimers altered the substrate preference toward MDM4 ubiquitination and promoted MDM2-dependent MDM4 degradation in cells. This MDM4-degrader activity of MMRi62 was found to be associated with potent apoptosis induction in leukemia cells. Interestingly, MMRi62 effectively induced apoptosis in p53 mutant, multidrug-resistant leukemia cells and patient samples in addition to p53 wild-type cells. In contrast, MMRi67 as a RING heterodimer disruptor and an enzymatic inhibitor of the MDM2-MDM4 E3 complex lacked MDM4-degrader activity and failed to induce apoptosis in these cells. In summary, this study identifies MMRi62 as a novel MDM2-MDM4-targeting agent and suggests that small molecules capable of promoting MDM4 degradation may be a viable new approach to killing leukemia cells bearing non-functional p53 by apoptosis.

Stem cell architecture drives myelodysplastic syndrome progression and predicts response to venetoclax-based therapy

Myelodysplastic syndromes (MDS) are heterogeneous neoplastic disorders of hematopoietic stem cells (HSCs). The current standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, almost 50% of MDS patients fail HMA therapy and progress to acute myeloid leukemia, facing a dismal prognosis due to lack of approved second-line treatment options. As cancer stem cells are the seeds of disease progression, we investigated the biological properties of the MDS HSCs that drive disease evolution, seeking to uncover vulnerabilities that could be therapeutically exploited. Through integrative molecular profiling of HSCs and progenitor cells in large patient cohorts, we found that MDS HSCs in two distinct differentiation states are maintained throughout the clinical course of the disease, and expand at progression, depending on recurrent activation of the anti-apoptotic regulator BCL-2 or nuclear factor-kappa B-mediated survival pathways. Pharmacologically inhibiting these pathways depleted MDS HSCs and reduced tumor burden in experimental systems. Further, patients with MDS who progressed after failure to frontline HMA therapy and whose HSCs upregulated BCL-2 achieved improved clinical responses to venetoclax-based therapy in the clinical setting. Overall, our study uncovers that HSC architectures in MDS are potential predictive biomarkers to guide second-line treatments after HMA failure. These findings warrant further investigation of HSC-specific survival pathways to identify new therapeutic targets of clinical potential in MDS.

Why Single-Cell Sequencing Has Promise in MDS

Myelodysplastic syndromes (MDS) are a heterogeneous group of diseases characterized by ineffective hematopoiesis. The risk of MDS is associated with aging and the accumulation of somatic mutations in hematopoietic stem cells and progenitors (HSPC). While advances in DNA sequencing in the past decade unveiled clonal selection driven by mutations in MDS, it is unclear at which stage the HSPCs are trapped or what prevents mature cells output. Single-cell-sequencing techniques in recent years have revolutionized our understanding of normal hematopoiesis by identifying the transitional cell states between classical hematopoietic hierarchy stages, and most importantly the biological activities behind cell differentiation and lineage commitment. Emerging studies have adapted these powerful tools to investigate normal hematopoiesis as well as the clonal heterogeneity in myeloid malignancies and provide a progressive description of disease pathogenesis. This review summarizes the potential of growing single-cell-sequencing techniques, the evolving efforts to elucidate hematopoiesis in physiological conditions and MDS at single-cell resolution, and discuss how they may fill the gaps in our current understanding of MDS biology.

TP53 Combined Phenotype Score Is Associated with the Clinical Outcome of TP53-Mutated Myelodysplastic Syndromes

Simple Summary

TP53 is the most frequently mutated genes in cancer, and mutations of TP53 are observed in 5–10% of patients in myelodysplastic syndrome (MDS). In patients with MDS, TP53 mutations are associated with adverse outcomes; however, there is still significant heterogeneity in these disease courses. We performed retrospective review of 107 patients with untreated TP53-mutated MDS, and identified that the functional impact of TP53 mutations, represented by phenotypic annotation of TP53 mutations (PHANTM) combined phenotype score is associated with prognosis. In patients with TP53-mutated MDS, we found that a higher PHANTM combined phenotype score is associated with poorer clinical outcome, and this has independent influence on prognosis accounting for IPSS-R and other risk variables. Our findings suggest that TP53-mutated MDS is heterogeneous and not all TP53 mutations harbor the same impact on prognosis. The PHANTM combined score adds to prognostic precision in MDS beyond previously reported TP53 allelic state.

Abstract

Mutations of TP53 are observed in 5–10% of patients in myelodysplastic syndrome (MDS) and are associated with adverse outcomes. Previous studies indicate that the TP53 allelic state and variant allele frequency of TP53 mutation impact patient outcomes, but there is significant heterogeneity within this MDS subgroup. We performed retrospective review of clinicopathologic and genomic information of 107 patients with TP53-mutated MDS. We assessed each mutation according to the phenotypic annotation of TP53 mutations (PHANTM) and analyzed the associations between predicted TP53 mutant function, represented by the PHANTM combined phenotype score, and overall survival (OS) using the log rank test and Cox regression. Our results indicated that patients with PHANTM combined phenotype score above the median (>1) had significantly shorter OS compared to those with scores below the median (median OS: 10.59 and 16.51 months, respectively, p = 0.025). This relationship remained significant in multivariable analysis (HR (95%CI): 1.62 (1.01–2.58), p = 0.044) and identified to have an independent prognostic influence, accounting for known risk such as IPSS-R and other standard risk variables. Our results suggest that the functional information of TP53 mutations, represented by PHANTM combined phenotype score, are associated with the clinical outcome of patients with TP53-mutated MDS.

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.

MYC overexpression is associated with an early disease progression from MDS to AML

Recent studies demonstrated that MYC epigenetically regulates AML cell survival and differentiation by suppressing IDH1/2-TET2-5hmC signaling and that MYC overexpression is associated with poor survival outcomes in multiple AML patient cohorts. However, the oncogenic roles of MYC in MDS remain to be explored. A total of 41 patients with de novo MDS were retrospectively identified using the Total Cancer Care database at the Moffitt Cancer Center. A total of 61 % of patients had low MYC expression and 39 % of patients had high MYC expression defined as MYC reactivity by immunohistochemical staining in ≥5% of bone marrow (BM) cells at the time of MDS diagnosis. The median MDS-to-AML progression free survival (PFS) was significantly shorter in the high MYC group (median PFS 9.3 vs. 17.7 months, HR = 2.328, p = 0.013). Further, overall survival (OS) was also shorter in the high MYC patients (median OS 19.7 vs. 51.7 months, HR = 2.299, p = 0.053). Multivariate analyses demonstrated that high MYC expression is an independent poor prognostic factor for the MDS-to-AML progression (HR = 2.275, p = 0.046). Our observations indicate that MYC may play a crucial role in MDS transformation to AML and the underlying mechanisms of MYC-driven MDS clonal expansion and leukemic transformation require further investigation.

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.

Gene mutation spectrum of patients with myelodysplastic syndrome and progression to acute myeloid leukemia

Aim:

This study aimed to investigate the regularity of gene mutations in patients with myelodysplastic syndrome (MDS) and in those that progressed to acute myeloid leukemia (MDS/AML).

Patients & methods:

High-throughput sequencing technology was used to detect gene mutations in 99 newly diagnosed patients with MDS or MDS/AML.

Results:

Gene mutations were detected in 88 patients. The mutation incidence in the MDS/AML group was significantly higher than that in the MDS group. Statistically significant differences were observed between the MDS with refractory anemia (MDS-RA) and MDS-RA with excess blasts groups and between the MDS/AML and MDS-RA groups.

Conclusion:

Our data demonstrate that there is a cumulative accumulation of gene mutations, especially in transcription factor genes, during disease progression in MDS and MDS/AML.

This study investigated the regularity of gene mutations in patients with myelodysplastic syndrome (MDS) and in those that have progressed to acute myeloid leukemia (MDS/AML). High-throughput sequencing was used to detect mutations in 58 genes with known clinical significance in 99 patients who were newly diagnosed with MDS or MDS/AML. A total of 28 mutated genes and 214 mutations were detected in 88 (88.9%) patients. The most frequently mutated gene was U2AF1 (13.55%; 29/214), followed by ASXL1 (10.28%; 22/214), TP53 (7.09%; 15/214), and RUNX1 (7.09%; 15/214). The mutation rate in the MDS/AML group was significantly higher than in the MDS group (100 vs 84.51%; p = 0.031). The average number of mutations per patient was 1.40, 2.20 and 2.64 in the MDS-refractory anemia (RA), MDS-RA with excess blast (RAEB) and MDS/AML groups, respectively. Statistically significant differences were observed between the MDS-RA and MDS-RAEB groups (p = 0.031) and between the MDS/AML and MDS-RA groups (p = 0.003). Signal transduction gene mutations were more frequent in the MDS/AML than in the MDS group (50% vs 22.54%; p = 0.014), especially in the FLT3 (14.29% vs 0; p = 0.005) and PTPN11 (17.86 vs 2.82%; p = 0.018) genes. Statistically significant (p < 0.05) correlations were found in 12 mutated gene combinations. TP53 mutations were mutually exclusive with RNA splicing factor gene mutations (p = 0.001). U2AF1 S34 mutations were associated with trisomy 8 (22.22 vs 5.97%; p = 0.03), and TP53 mutations were associated with complex karyotypes. Our data demonstrate that there is cumulative accumulation of gene mutations, especially in transcription factor genes, during disease progression in MDS and MDS/AML. The data also indicate there are synergistic pathogenicity and mutually exclusive effects among gene mutations and chromosomal abnormalities.

Predicting outcome in higher-risk myelodysplastic syndrome patients treated with azacitidine

5-Azacitidine (5-AZA) is widely used for the treatment of higher-risk myelodysplastic syndromes. However, response and survival rates vary considerably, while indicated treatment duration remains undefined. For these reasons, factors determining response and survival are of major importance. Clinical, morphological, flow cytometry, cytogenetic and molecular factors are discussed in this review. Biomarkers predictive of response and prognosis, as well as their link to the mode of action of 5-AZA are also addressed, shifting the focus from clinical practice to investigational research. Their use could further improve prognostic classification of 5-AZA treated higher-risk myelodysplastic syndromes in the near future.

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.

Low Plasma Citrate Levels and Specific Transcriptional Signatures Associated with Quiescence of CD34+ Progenitors Predict Azacitidine Therapy Failure in MDS/AML Patients

Simple Summary

Epigenetic drugs, such as azacitidine (AZA), hold promise in the treatment of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), however, the mechanisms predicting the patients’ response to AZA is not completely understood. Quiescence of hematopoietic CD34⁺ progenitors has been proposed as a predictive factor for AZA therapy failure in MDS/AML patients, but the interplay between CD34⁺ cell cycle status and their metabolic signature in a predisposition to AZA (non)responsiveness remains unclear. Our data on patients with MDS or AML with myelodysplasia-related changes (AML-MRC) suggest that AZA-responders have actively cycling CD34⁺ cells poised for erythro-myeloid differentiation, with high metabolic activity controlling histone acetylation. Conversely, the patients who progressed early on AZA therapy revealed quiescence signature of their CD34⁺ cells, with signs of reduced metabolically-controlled acetylation of histones needed for transcription-permissive chromatin configuration. Our study delineates plasma citrate levels and CD34⁺ cells’ transcriptional signatures associated with cycling status and metabolic characteristics as factors predicting the response to AZA monotherapy in MDS/AML-MRC patients.

Abstract

To better understand the molecular basis of resistance to azacitidine (AZA) therapy in myelodysplastic syndromes (MDS) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), we performed RNA sequencing on pre-treatment CD34⁺ hematopoietic stem/progenitor cells (HSPCs) isolated from 25 MDS/AML-MRC patients of the discovery cohort (10 AZA responders (RD), six stable disease, nine progressive disease (PD) during AZA therapy) and from eight controls. Eleven MDS/AML-MRC samples were also available for analysis of selected metabolites, along with 17 additional samples from an independent validation cohort. Except for two patients, the others did not carry isocitrate dehydrogenase (IDH)1/2 mutations. Transcriptional landscapes of the patients’ HSPCs were comparable to those published previously, including decreased signatures of active cell cycling and DNA damage response in PD compared to RD and controls. In addition, PD-derived HSPCs revealed repressed markers of the tricarboxylic acid cycle, with IDH2 among the top 50 downregulated genes in PD compared to RD. Decreased citrate plasma levels, downregulated expression of the (ATP)-citrate lyase and other transcriptional/metabolic networks indicate metabolism-driven histone modifications in PD HSPCs. Observed histone deacetylation is consistent with transcription-nonpermissive chromatin configuration and quiescence of PD HSPCs. This study highlights the complexity of the molecular network underlying response/resistance to hypomethylating agents.

Myelodysplasia Syndrome, Clonal Hematopoiesis and Cardiovascular Disease

Simple Summary

The development of blood cancers is a complex process that involves the acquisition of specific blood disorders that precede cancer. These blood disorders are often driven by the accumulation of genetic abnormalities, which are discussed in this review. Likewise, predicting the rate of progression of these diseases is difficult, but it appears to be linked to which specific gene mutations are present in blood cells. In this review, we discuss a variety of genetic abnormalities that drive blood cancer, conditions that precede clinical symptoms of blood cancer, and how alterations in these genes change blood cell function. Additionally, we discuss the novel links between blood cancer development and heart disease.

Abstract

The development of myelodysplasia syndromes (MDS) is multiphasic and can be driven by a plethora of genetic mutations and/or abnormalities. MDS is characterized by a hematopoietic differentiation block, evidenced by increased immature hematopoietic cells, termed blast cells and decreased mature circulating leukocytes in at least one lineage (i.e., cytopenia). Clonal hematopoiesis of indeterminate potential (CHIP) is a recently described phenomenon preceding MDS development that is driven by somatic mutations in hemopoietic stem cells (HSCs). These mutant HSCs have a competitive advantage over healthy cells, resulting in an expansion of these clonal mutated leukocytes. In this review, we discuss the multiphasic development of MDS, the common mutations found in both MDS and CHIP, how a loss-of-function in these CHIP-related genes can alter HSC function and leukocyte development and the potential disease outcomes that can occur with dysfunctional HSCs. In particular, we discuss the novel connections between MDS development and cardiovascular disease.

Do histone deacytelase inhibitors and azacitidine combination hold potential as an effective treatment for high/very-high risk myelodysplastic syndromes?

INTRODUCTION

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disorder, predominantly seen in elderly patients with variable clinical outcome and high tendency for leukemic transformation. Allogeneic hematopoietic stem cell transplantation (alloHCT) is the only potential curative option but limited to a selected group of patients, for the rest, disease control is the goal and enrollment in clinical trial is always encouraged. Mechanistically, azacitidine (AZA) and histone deacetylase inhibitors (HDACi) is a promising combination for patient with high-risk MDS to improve clinical outcome, but the combination has yet to demonstrate its efficacy in randomized clinical trials.

AREAS COVERED

In this review the authors discuss the salient features, pharmacokinetics, safety, and efficacy data of AZA and HDACi combination in patients with MDS. Future strategies on how to possibly improve clinical outcome of patients with MDS using AZA and HDACi combination are discussed.

EXPERT OPINION

Pre-clinical and clinical data demonstrated synergistic activity of AZA and HDACi in patients with MDS. So far, the efficacy of this combination is undermined by toxicity; mainly gastrointestinal. Careful patient selection and alternative dosing schedule is needed in future clinical trials to evaluate clinical outcome.

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.

Asia-inclusive global development of pevonedistat: Clinical pharmacology and translational research enabling a phase 3 multiregional clinical trial

Abstract

The investigational NEDD8‐activating enzyme inhibitor pevonedistat is being evaluated in combination with azacitidine versus single‐agent azacitidine in patients with higher‐risk myelodysplastic syndrome (higher‐risk MDS), higher‐risk chronic myelomonocytic leukemia (higher‐risk CMML), or low‐blast acute myeloid leukemia (AML) in a Phase 3 trial PANTHER. To support Asia‐inclusive global development, we applied multiregional clinical trial (MRCT) principles of the International Conference on Harmonisation E17 guidelines by evaluating similarity in drug‐related and disease‐related intrinsic and extrinsic factors. A PubMed literature review (January 2000–November 2019) supported similarity in epidemiology of higher‐risk MDS, AML, and CMML in Western and East Asian populations. Furthermore, the treatment of MDS/AML was similar in both East Asian and Western regions, with the same dose of azacitidine being the standard of care. Median overall survival in MDS following azacitidine treatment was generally comparable across regions, and the types and frequencies of molecular alterations in AML and MDS were comparable. Dose‐escalation studies established the same maximum tolerated dose of pevonedistat in combination with azacitidine in Western and East Asian populations. Pevonedistat clearance was similar across races. Taken together, conservation of drug‐related and disease‐related intrinsic and extrinsic factors supported design of an Asia‐inclusive Phase 3 trial and a pooled East Asian region. A sample size of ~ 30 East Asian patients (of ~ 450 randomized) was estimated as needed to demonstrate consistency in efficacy relative to the global population. This analysis is presented as an exemplar to illustrate application of clinical pharmacology and translational science principles in designing Asia‐inclusive MRCTs.

Deciphering the Key Pharmacological Pathways and Targets of Yisui Qinghuang Powder That Acts on Myelodysplastic Syndromes Using a Network Pharmacology-Based Strategy

Background

Yisui Qinghuang powder (YSQHP) is an effective traditional Chinese medicinal formulation used for the treatment of myelodysplastic syndromes (MDS). However, its pharmacological mechanism of action is unclear.

Materials and Methods

In this study, the active compounds of YSQHP were screened using the traditional Chinese medicine systems pharmacology (TCMSP) and HerDing databases, and the putative target genes of YSQHP were predicted using the STITCH and DrugBank databases. Then, we further screened the correlative biotargets of YSQHP and MDS. Finally, the compound-target-disease (C-T-D) network was conducted using Cytoscape, while GO and KEGG analyses were conducted using R software. Furthermore, DDI-CPI, a web molecular docking analysis tool, was used to verify potential targets and pathways. Finally, binding site analysis was performed to identify core targets using MOE software.

Results

Our results identified 19 active compounds and 273 putative target genes of YSQHP. The findings of the C-T-D network revealed that Rb1, CASP3, BCL2, and MAPK3 showed the most number of interactions, whereas indirubin, tryptanthrin, G-Rg1, G-Rb1, and G-Rh2 showed the most number of potential targets. The GO analysis showed that 17 proteins were related with STPK activity, PUP ligase binding, and kinase regulator activity. The KEGG analysis showed that PI3K/AKT, apoptosis, and the p53 pathways were the main pathways involved. DDI-CPI identified the top 25 proteins related with PI3K/AKT, apoptosis, and the p53 pathways. CASP8, GSK3B, PRKCA, and VEGFR2 were identified as the correlative biotargets of DDI-CPI and PPI, and their binding sites were found to be indirubin, G-Rh2, and G-Rf.

Conclusion

Taken together, our results revealed that YSQHP likely exerts its antitumor effects by binding to CASP8, GSK3B, PRKCA, and VEGFR2 and by regulating the apoptosis, p53, and PI3K/AKT pathways.

Impact of mutational variant allele frequency on prognosis in myelodysplastic syndromes

The clinical relevance of variant allele frequency (VAF) of recurrent mutations in myelodysplastic syndromes (MDS) has been increasingly reported. However, the prognostic value of mutational VAF across the genetic spectrum of MDS has not been extensively evaluated. In this study, we profiled the mutational spectrum of 382 newly diagnosed MDS patients using targeted next-generation sequencing. Exploratory analysis found that mutational VAF of some genes including TET2, TP53, and SF3B1 had significant associations with patient survival. Specifically, TET2 VAF ≥ 32% (HR 1.69, P = 0.025) and TP53 VAF ≥ 27% (HR 3.58, P < 0.001) were independently associated with shorter overall survival (OS). In contrast, SF3B1 VAF ≥ 15% had an independent association with better prognosis (HR 0.52, P = 0.048). In addition, high TET2 VAF was associated with an increased response to hypomethylating agents relative to low TET2 VAF (P = 0.009). Patients with high TP53 VAF more often possessed complex karyotypes than those with low VAF (P = 0.034). And patients with high SF3B1 VAF were more frequently classified as MDS with ring sideroblasts (MDS-RS) category than those with low VAF (P = 0.012). Meanwhile, we found that for some other genes like EZH2 and NRAS, once their mutations appeared, it meant poor survival regardless of mutational VAF. These findings suggest that mutational VAF of certain genes should be considered into the routine prognostic prediction and risk stratification of MDS patients.

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.

Germline DNMT3A mutation in familial acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a heterogeneous myeloid malignancy characterized by recurrent clonal events, including mutations in epigenetically relevant genes such as DNMT3A, ASXL1, IDH1/2, and TET2. Next-generation sequencing analysis of a mother and son pair who both developed adult-onset diploid AML identified a novel germline missense mutation DNMT3A p.P709S. The p.P709S protein-altering variant resides in the highly conserved catalytic DNMT3A methyltransferase domain. Functional studies demonstrate that the p.P709S variant confers dominant negative effects when interacting with wildtype DNMT3A. LINE-1 pyrosequencing and reduced representation bisulphite sequencing (RBBS) analysis demonstrated global DNA hypomethylation in germline samples, not present in the leukaemic samples. Somatic acquisition of IDH2 p.R172K mutations, in concert with additional acquired clonal DNMT3A events in both patients at the time of AML diagnosis, confirms the important pathogenic interaction of epigenetically active genes, and implies a strong selection and regulation of methylation in leukaemogenesis. Improved characterization of germline mutations may enable us to better predict malignant clonal evolution, improving our ability to provide customized treatment or future preventative strategies.

Prognostic impact of TP53 mutation, monosomal karyotype, and prior myeloid disorder in nonremission acute myeloid leukemia at allo-HSCT

Outcomes after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in nonremission acute myeloid leukemia (AML) are dismal [2-year overall survival (OS): 20-30%]. Though several risk classifications have been used, some factors are unavailable until the start of conditioning or transplantation. We analyzed prognostic gene mutations by targeted next-generation sequencing to identify predisposing factors for predicting OS at 1 month before transplantation. We enrolled 120 patients with nonremission AML who underwent first allo-HSCT between 2005 and 2018. Mutations were found in 98 patients; frequently mutated genes were FLT3-ITD, TP53, RUNX1, and WT1. TP53 mutation was detected in 21 patients and was the only predictor of poor OS. Multivariate analysis using Cox regression hazard model revealed primary AML, monosomal karyotype (MK), and TP53 mutation as independent factors for predicting poor OS. Based on these, patients were stratified into three groups. The low-risk group included patients with prior myeloid disorder without MK (n = 26). Among the rest, patients with TP53 mutation were assigned to the high-risk group (n = 19) and the rest into the intermediate-risk group (n = 75). Two-year OS in low-, intermediate-, and high-risk groups differed significantly (50.0%, 24.9%, and 0%, respectively). This suggests that the indication of allo-HSCT should be carefully judged for high-risk patients.

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.

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.

Do next-generation sequencing results drive diagnostic and therapeutic decisions in MDS?

This article has a companion Point by Thol and Platzbecker.

NPM1 mutations define a specific subgroup of MDS and MDS/MPN patients with favorable outcomes with intensive chemotherapy

Nucleophosmin (NPM1) mutations are common in acute myeloid leukemia and are associated with high remission rates and prolonged survival with intensive chemotherapy. NPM1 mutations are rare in myelodysplastic syndromes (MDS) or myelodysplastic/myeloproliferative neoplasm (MDS/MPN), and the clinical outcomes of these patients, when treated with intensive chemotherapy, are unknown. We retrospectively evaluated the clinicopathologic characteristics and the impact of therapy in 31 patients with MDS or MDS/MPN and NPM1 mutations. Next-generation sequencing was performed at diagnosis in 22 patients. Median age was 62 years (range, 19-86). Twenty-four patients (77%) had normal karyotype, and all had multilineage dysplasia. Most patients could be classified as MDS with excess blasts (19/31, 61%). NPM1 mutations were detected at a median allele frequency of 0.38 (range, 0.09-0.49). Mutation burden did not correlate with bone marrow blast frequency, and its clearance seemed to be associated with decreased morphologic dysplasia. Ten of the 31 patients (32%) received cytotoxic chemotherapy, 20 (65%) hypomethylating agents, and 1 (4%) lenalidomide. Sequential sequencing was available in 16 (52%) patients, and mutation burden correlated with disease status and response to therapy. Patients treated with chemotherapy had higher complete response rates (90% vs 28%, P = .004), longer median progression-free survival (not reached vs 7.5 months, P = .023), and overall survival (not reached vs 16 months, P = .047). Intensive chemotherapy and allogeneic stem cell transplantation (SCT) may be associated with improved clinical outcomes in patients with NPM1-mutated MDS or MDS/MPN who are candidates for this form of therapy.

Clonal selection in therapy-related myelodysplastic syndromes and acute myeloid leukemia under azacitidine treatment

INTRODUCTION

Therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) are defined as complications of previous cytotoxic therapy. Azacitidine (AZA), a hypomethylating agent, has showed activity in t-MDS/AML.

OBJECTIVES

We evaluated the clonal dynamics of AZA-treated t-MDS/AML.

METHODS

We collected bone marrow samples, at diagnosis and during treatment, from AZA-treated t-MDS/AML patients. NGS on 19 myeloid genes was performed, and candidate mutations with a variant allele frequency >5% were selected.

RESULTS

Seven t-AML and 12 t-MDS were included with median age of 71 (56-82) years old, median number of AZA cycles of 6 (1-15), and median overall survival (OS) of 14 (3-29) months. We observed correlation between AZA response and clonal selection. Decrease of TP53-mutated clone was correlated with response to AZA, confirming AZA efficacy in this subgroup. In some patients, emergence of mutations was correlated with progression or relapse without impact on OS. Clones with mutations in genes for DNA methylation regulation frequently occurred with other mutations and remained stable during AZA treatment, independent of AZA response.

CONCLUSION

We confirmed that the molecular complexity of t-MNs and that the follow-up of clonal selection during AZA treatment could be useful to define treatment combination.

The face of remission induction

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

In MDS, is higher risk higher reward?

Patients with higher-risk myelodysplastic syndrome (HR-MDS) are defined by the original or revised International Prognostic Scoring System and specific genetic features. Treatment of HR-MDS is challenging. Allogeneic hematopoietic stem cell transplantation, the only curative approach, is feasible in a minority of fit or intermediate fitness patients aged <70 to 75 years who are willing to face the risks of the procedure. Response to azacitidine and decitabine, the only approved drugs for HR-MDS and considered the standard of care, is partial and transient in most patients. The development of novel more personalized and efficient drugs is an unmet medical need. During the last decade, there have been substantial advances in understanding the multiple molecular, cellular, and immunological disturbances involved in the pathogenesis of myelodysplastic syndrome. As a result, a number of clinical and translational studies of new more focused treatment approaches for HR-MDS patients are underway. In contrast to acute myeloid leukemia, they have not resulted in any new drug approval. This review addresses the benefits and limitations of current treatment alternatives, offers a practical individualized treatment approach, and summarizes the clinical trials in progress for HR-MDS.