DS-5272

Co-treatment with rapamycin and DS-5272 had a dramatic in vivo effect on MLL-AF9-driven AML, curing 85% of the leukemic mice. Thus, machine learning-based predictive approaches identified monocytic AML with wild-type TP53 and low Rapa-11 score as a rapamycin-sensitive AML subtype and an ideal target for mTOR/p53 co-targeting therapy.

Preclinical and mechanistic rationale and preliminary clinical data support the future development of MDM2/FLT3 targeting strategies for FLT3-mutant AML.

In a syngeneic mouse model of acute myeloid leukemia (AML), Trp53 deletion in BM-MSCs improved survival, and protected BM against hematopoietic toxicity from a murine Mdm2i, DS-5272. The transcriptional changes were associated with dysregulation of glycolysis, gluconeogenesis, and Hif-1α in BM-MSCs. Our results reveal a physiologic function of Mdm2 in BM-MSC, identify a previously unknown role of p53 pathway in BM-MSC-mediated support in AML and expand our understanding of the mechanism of hematopoietic toxicity of MDM2is.

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. 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.

Herein, we characterized the antiangiogenic and antitumor effects of the MDM2 inhibitors DS-3032b and DS-5272 in 6 clear cell ovarian carcinoma cell lines and 2 clear cell renal carcinoma cell lines, as well as in clear cell ovarian carcinomas s.c. xenograft and ID8 (murine ovarian cancer cells with WT TP53) cancer peritonitis mouse models. Meanwhile, combined therapy with MDM2 inhibitors and everolimus showed synergistic, and dose-reduction potential, for clear cell carcinoma treatment. Our findings suggest that Murine double-minute 2 inhibitors represent promising molecular targeted therapy for clear cell carcinomas, thereby warranting further studies to evaluate the efficacy and safety of dual Murine double-minute 2/mammalian target of rapamycin inhibitors in clear cell carcinoma patients.

Here we show that an orally active inhibitor of p53-MDM2 interaction, DS-5272, causes dramatic tumor regressions of MLL-AF9-driven AML in vivo with a tolerable toxicity...We also found that NK cells are important mediators of antileukemia immunity. Our study showed the potent activity of a p53-activating drug against AML, which is further augmented by antitumor immunity.