Clofarabine Improves Relapse-Free Survival of Acute Myeloid Leukemia in Younger Adults with Micro-Complex Karyotype

The Prognostic Value of TP53 Mutations in Adult Acute Myeloid Leukemia: A Meta-Analysis

OBJECTIVE

Mutations of the tumor protein p53 (TP53) gene were considered to be associated with an unfavorable prognosis in acute myeloid leukemia (AML). This meta-analysis aimed to systematically elucidate the prognostic value of TP53 mutation in adult patients with AML.

METHOD

A comprehensive literature search was conducted for eligible studies published before August 2021. The primary endpoint was overall survival (OS). Pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) were calculated for prognostic parameters. Subgroup analyses based on intensive treatment were performed.

RESULTS

Thirty-two studies with 7,062 patients were included. As compared to wild-type carriers, AML patients with TP53 mutations had significantly shorter OS (HR: 2.40, 95% CI: 2.16-2.67, I2: 46.6%). Similar results were found in DFS (HR: 2.87, 95% CI: 1.88-4.38), EFS (HR: 2.56, 95% CI: 1.97-3.31), and RFS (HR: 2.40, 95% CI: 1.79-3.22). Mutant TP53 predicted inferior OS (HR: 2.77, 95% CI: 2.41-3.18) in the intensively treated AML subgroup, compared with the non-intensively treated group (HR: 1.89, 95% CI: 1.58-2.26). Among intensively-treated AML patients, the age of 65 did not affect the prognostic value of TP53 mutations. Besides, TP53 mutation was also strongly associated with an elevated risk of adverse cytogenetics, which conferred a dismal OS in AML patients (HR: 2.03, 95% CI: 1.74-2.37).

CONCLUSION

TP53 mutation exhibits a promising potential for discriminating AML patients with a worse prognosis, thus being capable of serving as a novel tool for prognostication and therapeutic decision-making in the management of AML.

Testicular disposition of clofarabine in rats is dependent on equilibrative nucleoside transporters

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and adolescents. Although the 5-year survival rate is high, some patients respond poorly to chemotherapy or have recurrence in locations such as the testis. The blood-testis barrier (BTB) can prevent complete eradication by limiting chemotherapeutic access and lead to testicular relapse unless a chemotherapeutic is a substrate of drug transporters present at this barrier. Equilibrative nucleoside transporter (ENT) 1 and ENT2 facilitate the movement of substrates across the BTB. Clofarabine is a nucleoside analog used to treat relapsed or refractory ALL. This study investigated the role of ENTs in the testicular disposition of clofarabine. Pharmacological inhibition of the ENTs by 6-nitrobenzylthioinosine (NBMPR) was used to determine ENT contribution to clofarabine transport in primary rat Sertoli cells, in human Sertoli cells, and across the rat BTB. The presence of NBMPR decreased clofarabine uptake by 40% in primary rat Sertoli cells (p = .0329) and by 53% in a human Sertoli cell line (p = .0899). Rats treated with 10 mg/kg intraperitoneal (IP) injection of the NBMPR prodrug, 6-nitrobenzylthioinosine 5'-monophosphate (NBMPR-P), or vehicle, followed by an intravenous (IV) bolus 10 mg/kg dose of clofarabine, showed a trend toward a lower testis concentration of clofarabine than vehicle (1.81 ± 0.59 vs. 2.65 ± 0.92 ng/mg tissue; p = .1160). This suggests that ENTs could be important for clofarabine disposition. Clofarabine may be capable of crossing the human BTB, and its potential use as a first-line treatment to avoid testicular relapse should be considered.

The Impact of DNMT3A Status on NPM1 MRD Predictive Value and Survival in Elderly AML Patients Treated Intensively

Simple Summary

DNMT3A mutation has been associated with adverse outcomes. In this study, we aimed to investigate the impact of DNMT3A status on NPM1 MRD predictive value for survival in a retrospective cohort of acute myeloid leukemia (AML) patients aged over 60 years old treated intensively. A total of 138 patients treated for NPM1-mutated AML in two French institutions were analyzed retrospectively. A 4log reduction of NPM1 MRD was associated with a better outcome. DNMT3A negative patients who achieved a 4log reduction had a superior outcome to those who did not. However, postinduction NPM1 MRD1 reduction was not predictive of OS and LFS in DNMT3Amut patients. These results confirm that post-induction NPM1 MRD1 is a reliable tool to assess disease outcome in elderly AML patients. However, the presence of DNMT3A also identify a subgroup of patients at high risk of relapse.

Abstract

Minimal residual disease (MRD) is now a powerful surrogate marker to assess the response to chemotherapy in acute myeloid leukemia (AML). DNMT3A mutation has been associated with adverse outcomes. In this study, we aimed to investigate the impact of DNMT3A status on NPM1 MRD predictive value for survival in a retrospective cohort of AML patients aged over 60 years old treated intensively. A total of 138 patients treated for NPM1-mutated AML in two French institutions were analyzed retrospectively. DNMT3A status did not influence the probability of having a ≥ 4log MRD1 reduction after induction. Only 20.4% of FLT3-ITD patients reached ≥ 4log MRD1 reduction compared to 47.5% in FLT3wt cases. A 4log reduction of NPM1 MRD was associated with a better outcome, even in FLT3-ITD mutated patients, independent of the allelic ratio. DNMT3A negative patients who reached a 4log reduction had a superior outcome to those who did not (HR = 0.23; p < 0.001). However, postinduction NPM1 MRD1 reduction was not predictive of OS and LFS in DNMT3Amut patients. These results confirm that post-induction NPM1 MRD1 is a reliable tool to assess disease outcome in elderly AML patients. However, the presence of DNMT3A also identifies a subgroup of patients at high risk of relapse.

Targeting LSD1 for acute myeloid leukemia (AML) treatment

Targeted therapy for acute myeloid leukemia (AML) is an effective strategy, but currently there are very limited therapeutic targets for AML treatment. Histone lysine specific demethylase 1 (LSD1) is highly expressed in many cancers, impedes the differentiation of cancer cells, promotes the proliferation, metastasis and invasion of cancer cells, and is associated with poor prognosis. Targeting LSD1 has been recognized as a promising strategy for AML treatment in recent years. Based on these features, in the review, we discussed the main epigenetic drugs targeting LSD1 for AML therapy. Thus, this review focuses on the progress of LSD1 inhibitors in AML treatment, particularly those such as tranylcypromine (TCP), ORY-1001, GSK2879552, and IMG-7289 in clinical trials. These inhibitors provide novel scaffolds for designing new LSD1 inhibitors. Besides, combined therapies of LSD1 inhibitors with other drugs for AML treatment are also highlighted.