Overexpression of TP53 is associated with poor survival, but not with reduced response to hypomethylating agents in older patients with acute myeloid leukaemia

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.

Ibrutinib added to 10-day decitabine for older patients with AML and higher risk MDS

The treatment of older, unfit patients with acute myeloid leukemia (AML) is challenging. Based on preclinical data of Bruton tyrosine kinase expression/phosphorylation and ibrutinib cytotoxicity in AML blasts, we conducted a randomized phase 2 multicenter study to assess the tolerability and efficacy of the addition of ibrutinib to 10-day decitabine in unfit (ie, Hematopoietic Cell Transplantation Comorbidity Index ≥3) AML patients and higher risk myelodysplasia patients (HOVON135/SAKK30/15 trial). In total, 144 eligible patients were randomly (1:1) assigned to either 10-day decitabine combined with ibrutinib (560 mg; sequentially given, starting the day after the last dose of decitabine) (n = 72) or to 10-day decitabine (n = 72). The addition of ibrutinib was well tolerated, and the number of adverse events was comparable for both arms. In the decitabine plus ibrutinib arm, 41% reached complete remission/complete remission with incomplete hematologic recovery (CR/CRi), the median overall survival (OS) was 11 months, and 2-year OS was 27%; these findings compared with 50% CR/CRi, median OS of 11.5 months, and 2-year OS of 21% for the decitabine group (not significant). Extensive molecular profiling at diagnosis revealed that patients with STAG2, IDH2, and ASXL1 mutations had significantly lower CR/CRi rates, whereas patients with mutations in TP53 had significantly higher CR/CRi rates. Furthermore, multicolor flow cytometry revealed that after 3 cycles of treatment, 28 (49%) of 57 patients with available bone marrow samples had no measurable residual disease. In this limited number of cases, measurable residual disease revealed no apparent impact on event-free survival and OS. In conclusion, the addition of ibrutinib does not improve the therapeutic efficacy of decitabine. This trial was registered at the Netherlands Trial Register (NL5751 [NTR6017]) and has EudraCT number 2015-002855-85.

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.

Clinical efficacy of decitabine in combination with standard-dose cytarabine, aclarubicin hydrochloride, and granulocyte colony-stimulating factor in the treatment of young patients with newly diagnosed acute myeloid leukemia

Purpose: The chemotherapeutic regimen DCAG (decitabine with cytarabine, aclarubicin hydrochloride, and granulocyte colony-stimulating factor) is effective for elderly patients with acute myeloid leukemia, but recommendations for young patients remain controversial. This study investigated the tolerance and efficacy of DCAG for patients with newly diagnosed acute myeloid leukemia (aged 14–60 years). The clinical features or molecular markers that may predict response to DCAG were identified.

Patients and methods: One-hundred sixty-one consecutive patients with newly diagnosed acute myelogenous leukemia received DCAG or standard (idarubicin plus cytarabine, IA) induction chemotherapy (n=64 and 97, respectively).

Results: The rates of complete remission after the first cycle, overall survival (OS), and event-free survival (EFS) were comparable. After the second cycle, the complete remission rate of the DCAG group (54.7%) was significantly lower than that of the reference (78.35%, P=0.005). The following were associated with significantly worse OS, and EFS, in the DCAG group: Eastern Cooperative Oncology Group (ECOG) score ≥3 and no response after the second induction therapy; and FLT3-ITD. The multivariate analysis showed the DCAG group with significantly shorter OS associated with ECOG ≥3 and FLT3-ITD. In the DCAG group, after the first cycle of induction chemotherapy the median recovery times of neutrophils and platelets were 15.8 and 13 days.

Conclusion: The DCAG and IA groups were similar with regard to complete remission rate after the first cycle, OS, and EFS. The complete remission rate after the second cycle of the DCAG was significantly lower than that of the IA. Grade 4 neutropenia and thrombocytopenia were a major adverse event associated with DCAG.

Can we predict responsiveness to hypomethylating agents in AML?

DNA-hypomethylating agents (HMAs) were developed as nonintensive treatment alternatives to standard chemotherapy in older, unfit patients with acute myeloid leukemia and myelodysplastic syndrome. Given their distinct effects on the methylome and transcriptome of malignant cells compared to cytarabine (Ara-C) and other cytotoxic drugs not inhibiting DNA methyltransferases, it is of great interest to define their specific clinical ``signature.'' Here, we present and discuss clinical, genetic, and epigenetic predictors of responsiveness to HMAs. Indeed, mounting evidence supports the notion that HMAs are not "just another kind of low-dose Ara-C." Not only patient factors (age, performance status, comorbidities, etc.), blast counts, and early platelet response, but also adverse genetics (monosomal karyotype and/or a TP53 mutation) have predictive potential. Given the surprising-and initially counterintuitive-responses observed in patients with the latter features, these are subject to mechanistic studies to elucidate their as yet unresolved interaction with HMAs. Finally, other potential biomarkers for HMA response such as elevated fetal hemoglobin might also contribute to overcome the present challenges in predicting responsiveness to HMAs.