Aptose Biosciences Inc. (NASDAQ: APTO) has announced that oral myeloid kinome inhibitor HM43239 has shown durable single-agent activity in refractory/relapsed acute myeloid leukemia patients. The Company presented the data during the 2021 American Society of Haematology Annual Conference lead by principal investigator Naval Daver, Associated Professor at MD Anderson Cancer Center Department of Leukemia.
HM43239 demonstrated in vivo and in vitro efficacy
HM43239 is a potent oral, once-daily myeloid kinome inhibitor (MKI) that targets key kinases involved in myeloid malignancies. It has previously shown strong in vivo and in vitro effectiveness against FLT3 ITD mutant AML and resistance-inducing D835 and gatekeeper (F691) TKD mutated AML in preclinical trials. Equally, HM43239 decreased phosphorylation of SYK, which is significantly active in AML and linked to resistance to FLT3 targeted therapy.
Chief Medical officer Rafael Bejar said, “HM43239 demonstrated clear genotype-agnostic clinical activity as a single-agent in one of the most challenging and most heterogeneus disease settings in oncology today – relapsed and refractory AML. Importantly, HM43239 has demonstrated activity in patients with FLT3 wild-type AML, FLT3 mutated AML, NPM1 mutated AML, as well as in patients with mutations historically associated with resistance to targeted therapy, such as TP53, NRAS, KRAS, and others. We believe that the clinical activity observed to date could support a broad expansion program covering multiple genotypes and disease stages in AML.”
Hematological malignancies show drug resistance
Chairman and CEO William Rice commented, “Drug resistance remains a tremendous challenge in hematologic malignancies, and we plan to leverage our growing bench of kinase inhibitors to tackle unmet needs across multiple indications and multiple disease genotypes. Our newest and most mature investigational drug, HM43239, is demonstrating activity against some of the most challenging AML genotypes and we look forward to continuing to advance it towards registration-enabling studies. Luxeptinib also continues to show positive trends of activity in both B-cell cancers and AML. We look forward to bringing on a new formulation of Lux that may help increase exposure levels further, and potentially deliver faster and deeper antitumor activity in hematologic malignancies.”
