Objective
Acute myeloid leukemia (AML) with mutations in the tumor suppressor gene TP53 confers a dismal prognosis with 1‐year overall survival of <5%. Effective treatment options are limited and ...current standard‐of‐care includes the hypomethylating agents (HMA) decitabine and azacytidine. While inhibition of kinases involved in cell cycle regulation has been shown to induce synthetic lethality in a variety of TP53 mutant cancers, this strategy has not been evaluated in mutant TP53 AML. Previously, we demonstrated that TP‐0903 is a novel multikinase inhibitor with low nM activity against AURKA/B, CHEK1/2, and other cell cycle regulators (Jeon JY et al. JCI Insight 2020), thus providing scientific rationale to evaluate TP‐0903 activity in TP53 mutant AML.
Methods
To generate an in vitro model of TP53 mutant AML, we isolated single‐cell clones containing mutant (R248W) or wild‐type (WT) TP53 from the established MV4‐11 AML cell line; regulation of p53 targets (MDM2, p21) following gamma irradiation and inhibition of p‐AURKA and p‐CHEK1 by TP‐0903 were assessed by immunoblot. Using these and additional TP53 mutant AML cell lines (Kasumi‐1, HL‐60), in vitro efficacy of TP‐0903 alone and in combination with HMA was assessed in viability (MTT) and apoptosis (Annexin V) assays. In vivo efficacy studies were conducted in NSG mice following intravenous injection of HL‐60 or luciferase‐tagged MV4‐11/TP53‐R248W cells. Mice (5‐10 per treatment cohort) were treated with vehicle, TP‐0903 (50 mg/kg orally; 5 days on/2 days off), decitabine (0.2‐0.4 mg/kg i.p.; 4 days on/10 days off) or the combination. Whole body bioluminescence imaging was performed weekly and median survival was determined.
Results
Compared to the clone with WT TP53, we observed a lack of MDM2 and p21 induction in MV4‐11/TP53‐R248W cells following gamma irradiation. In vitro, TP‐0903 inhibited pAURKA and pCHEK1 at 50 nM, inhibited cell viability (IC50 values, 12‐40nM), and induced apoptosis at 20‐50nM. The combination of TP‐0903 with HMA was additive to synergistic in all AML cell lines evaluated. In the HL‐60 xenograft model, the TP‐0903/decitabine combination prolonged median survival (75 days) compared to cohorts of mice treated with TP‐0903 (63 days), decitabine (55 days), or vehicle (46 days) (P<0.0001). In the MV4‐11/TP53‐R248W xenograft model, bioluminescence imaging showed that TP‐0903 alone or in combination with decitabine was more effective in suppressing the outgrowth of leukemia cells compared to mice treated with vehicle or decitabine alone (P<0.05); survival analysis is ongoing.
Conclusions
TP‐0903 was effective in all evaluated preclinical models of TP53 mutant AML. Together, these results provide scientific premise for the initiation of a Phase 1b/2 trial of TP‐0903 in combination with decitabine in TP53 mutant/complex karyotype AML under the umbrella Beat AML Master Trial.
Chronic lymphocytic leukemia (CLL) is effectively treated with targeted therapies including Bruton tyrosine kinase inhibitors and BCL2 antagonists. When these become ineffective, treatment options ...are limited. Positive transcription elongation factor complex (P-TEFb), a heterodimeric protein complex composed of cyclin dependent kinase 9 (CDK9) and cyclin T1, functions to regulate short half-life transcripts by phosphorylation of RNA Polymerase II (POLII). These transcripts are frequently dysregulated in hematologic malignancies; however, therapies targeting inhibition of P-TEFb have not yet achieved approval for cancer treatment. VIP152 kinome profiling revealed CDK9 as the main enzyme inhibited at 100 nM, with over a 10-fold increase in potency compared with other inhibitors currently in development for this target. VIP152 induced cell death in CLL cell lines and primary patient samples. Transcriptome analysis revealed inhibition of RNA degradation through the AU-Rich Element (ARE) dysregulation. Mechanistically, VIP152 inhibits the assembly of P-TEFb onto the transcription machinery and disturbs binding partners. Finally, immune competent mice engrafted with CLL-like cells of Eµ-MTCP1 over-expressing mice and treated with VIP152 demonstrated reduced disease burden and improvement in overall survival compared to vehicle-treated mice. These data suggest that VIP152 is a highly selective inhibitor of CDK9 that represents an attractive new therapy for CLL.
Recently, the European LeukemiaNet (ELN) revised its genetic-risk classification of acute myeloid leukemia (AML). We categorized 1637 adults with AML treated with cytarabine/anthracycline regimens ...according to the 2022 and 2017 ELN classifications. Compared with the 2017 ELN classification, 2022 favorable group decreased from 40% to 35% and adverse group increased from 37% to 41% of patients. The 2022 genetic-risk groups seemed to accurately reflect treatment outcomes in all patients and patients aged <60 years, but in patients aged ≥60 years, relapse rates, disease-free (DFS) and overall (OS) survival were not significantly different between intermediate and adverse groups. In younger African-American patients, DFS and OS did not differ between intermediate-risk and adverse-risk patients nor did DFS between favorable and intermediate groups. In Hispanic patients, DFS and OS did not differ between favorable and intermediate groups. Outcome prediction abilities of 2022 and 2017 ELN classifications were similar. Among favorable-risk patients, myelodysplasia-related mutations did not affect patients with CEBPA
mutations or core-binding factor AML, but changed risk assignment of NPM1-mutated/FLT3-ITD-negative patients to intermediate. NPM1-mutated patients with adverse-risk cytogenetic abnormalities were closer prognostically to the intermediate than adverse group. Our analyses both confirm and challenge prognostic significance of some of the newly added markers.
Clinical outcome of patients with acute myeloid leukemia (AML) is associated with cytogenetic and molecular factors and patient demographics (e.g., age and race). We compared survival of 25,523 ...non-Hispanic Black and White adults with AML using Surveillance Epidemiology and End Results (SEER) Program data and performed mutational profiling of 1,339 patients with AML treated on frontline Alliance for Clinical Trials in Oncology (Alliance) protocols. Black patients had shorter survival than White patients, both in SEER and in the setting of Alliance clinical trials. The disparity was especially pronounced in Black patients <60 years, after adjustment for socioeconomic (SEER) and molecular (Alliance) factors. Black race was an independent prognosticator of poor survival. Gene mutation profiles showed fewer
and more
mutations in younger Black patients. Overall survival of younger Black patients was adversely affected by
mutations and
-ITD, but, in contrast to White patients, was not improved by
mutations. SIGNIFICANCE: We show that young Black patients have not benefited as much as White patients from recent progress in AML treatment in the United States. Our data suggest that both socioeconomic factors and differences in disease biology contribute to the survival disparity and need to be urgently addressed.
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Using broad interrogation of clinically relevant drug absorption, distribution, metabolism, and excretion (ADME) genes on the DMET platform, we identified a genetic variant in SLCO1B1 (rs2291075; ...c.597C>T), encoding the transporter OATP1B1, associated with event‐free (P = 0.006, hazard ratio = 1.74) and overall survival (P = 0.012, hazard ratio = 1.85) in children with de novo acute myeloid leukemia (AML). Lack of SLCO1B1 expression in leukemic blasts suggested the association might be due to an inherited rather than a somatic effect. rs2291075 was in strong linkage with known functional variants rs2306283 (c.388A>G) and rs4149056 (c.521T>C). Functional studies in vitro determined that four AML‐directed chemotherapeutics (cytarabine, daunorubicin, etoposide, and mitoxantrone) are substrates for OATP1B1 and the mouse ortholog Oatp1b2. In vivo pharmacokinetic studies using Oatp1b2‐deficient mice further confirmed our results. Collectively, these findings demonstrate an important role for OATP1B1 in the systemic pharmacokinetics of multiple drugs used in the treatment of AML and suggest that inherited variability in host transporter function influences the effectiveness of therapy.
Summary
Somatic mutation of the DNMT3A gene at the arginine R882 site is common in acute myeloid leukaemia (AML). The prognostic significance of DNMT3A R882 mutation clearance, using traditional ...diagnostic next generation sequencing (NGS) methods, during complete remission (CR) in AML patients is controversial. We examined the impact of clearing DNMT3A R882 mutations at diagnosis to the detectable threshold of ˂3% during CR on outcome in 56 adult AML patients. Mutational remission, defined as clearance of pre‐treatment DNMT3A R882 and all other AML‐associated mutations to a variant allele frequency ˂3%, occurred in 14 patients whereas persistent DNMT3A R882 mutations were observed in 42 patients. There were no significant differences in disease‐free or overall survival between patients with and without DNMT3A R882 mutation clearance. Patients with persistent DNMT3A R882 who cleared all other AML mutations and did not acquire new mutations (n = 30), trended towards longer disease‐free survival (1·6 vs. 0·6 years, P = 0·06) than patients with persistence of DNMT3A R882, in addition to other mutations or acquisition of new AML‐associated mutations, such as those in TET2, JAK2, ASXL1 and TP53 (n = 12). These data demonstrate that DNMT3A R882 mutations, as assessed by traditional NGS methods, persist in the majority of AML patients in CR.
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