HM43239 Granted Fast Track Designation for AML

The FDA has granted Fast Track Designation to Aptose Biosciences’ HM43239, an oral myeloid kinome inhibitor, for the treatment of patients with relapsed/refractory FLT3-mutated AML.

There is currently a phase I/II clinical trial evaluating HM43239 in this patient population. The drug previously received Orphan Drug Designation for the treatment of AML in 2018.

According to a press release, HM43239 is a potent inhibitor of FLT3, SYK, mutant forms of cKIT, JAK1/2, and other kinases. Previous research has shown that HM43239 is highly active in vivo against FLT3 internal tandem duplication, as well as resistance-conferring D835 and gatekeeper (F691) tyrosine kinase domain mutations.

In vivo murine xenograft models suggest superior antitumor activity and favorable tolerability relative to established kinase inhibitor in AML, including gilteritinib (FLT3 inhibitor) and entospletinib (SYK inhibitor). Additionally, in vivo xenograft models suggest synergy with inhibitors of DNMT, BCL-2, and other key therapeutic targets, highlighting the combinatorial optionality of HM43239 in AML.

Source: Aptose press release, May 2022