PLX3397 is an oral agent that selectively co-inhibits three key targets, allows down-modulation of a number of cell types, as well as inhibits Flt3 mutations that are responsible for AML.
In a preclinical model of AML, PLX3397 showed tumor regression and retained activity against certain drug-resistant forms of mutated Flt3 that can occur with other treatments.
Phase 1 dose escalation testing in patients with solid tumors showed that PLX3397 reached therapeutic drug levels that were well tolerated at the doses tested, and further the two ongoing Phase 2 studies will evaluate PLX3397.
In addition, PLX3397 has also been tested in primary AML patient blood samples, which showed a clear dose response to drug at clinically achievable drug levels.