Cell experiment:

Colony-forming cell (CFC) units are assayed in methylcellulose supplemented with 10 ng/mL IL-3, 10 ng/mL GM-CSF, 50 ng/ mL SCF, 50 ng/mL FLT3-ligand and 3 U/mL EPO. Vehicle or BAY-1436032 is added to methylcellulose containing 105 human mononuclear cells, which are plated in duplicate. Colonies are evaluated microscopically 10 to 14 days after plating by standard criteria[1].

Animal experiment:

NSG mice are used and transplanted with primary acute myeloid leukemia (AML) cells from a patient with IDH1R132C mutant AML. Per condition 10 mice are treated with vehicle, 45 or 150 mg/kg body weight BAY-1436032 once daily by oral gavage for 150 days starting 17 days after transplantation. Finally, serum R-2HG levels and human CD45+ (hCD45+) cells are measured[1].

BAY-1436032 is a novel pan-mutant isocitrate dehydrogenase 1 (IDH1) inhibitor.

BAY-1436032 is a novel pan-mutant isocitrate dehydrogenase 1 (IDH1) inhibitor. BAY-1436032 inhibits intracellular (R)-2-hydroxyglutarate (R-2HG) production in mouse hematopoietic cells expressing IDH1R132H or IDH1R132C with IC50s of 60 and 45 nM, respectively. R-2HG levels are not reduced in IDH2R140Q and IDH2R172K expressing mouse hematopoietic cells by BAY-1436032 at concentrations up to 10 uM. Colony growth is inhibited by 50% at a concentration of 0.1 uM BAY-1436032, while concentrations up to 100 uM do not suppress colony growth of patient-derived IDH1 wild-type AML cells. On morphologic evaluation myelomonocytic differentiation of myeloid progenitors is strongly induced by BAY-1436032[1].

Long-term exposure to once daily oral BAY-1436032 reveals nearly complete suppression of (R)-2-hydroxyglutarate (R-2HG) production with 150 mg/kg BAY1436032. White blood cell counts constantly increase in vehicle-treated mice and, at a lower rate, in animals receiving 45 mg/kg BAY-1436032, while they remain constant in the 150 mg/kg cohort. Hemoglobin levels are slightly lower in the vehicle and 45 mg/kg groups as compare to the 150 mg/kg cohort at day 60, while platelet counts are significantly reduced in vehicle and 45 mg/kg BAY-1436032 treated mice compare to the 150 mg/kg cohort at day 60. All mice receiving 150 mg/kg BAY-1436032 survive with minimal hCD45+ cell load in their peripheral blood until the end of observation at day 150 after treatment start (P<0.001), while vehicle-treated animals die from leukemia with a median survival of 91 days. Mice treated with 45 mg/kg BAY-1436032 display intermediate levels of CD14/CD15 expression[1].

References:
[1]. Chaturvedi A, et al. Pan-mutant-IDH1 inhibitor BAY1436032 is highly effective against human IDH1 mutant acute myeloid leukemia in vivo. Leukemia. 2017 Oct;31(10):2020-2028.