In vivo, VER-50589 administered at 4 mg/kg intraperitoneally achieves complete HSP90 inhibition in mice with OVCAR3 human ovarian ascites tumors, and at 100 mg/kg, it significantly reduces tumor volume and weight in HCT116 colon carcinoma xenografts compared to control mice^[1].

VER-50589 is a Hsp90 inhibitor, with an IC50 of 21 nM and a Kd of 4.5 nM. It effectively blocks the intrinsic ATPase activity of recombinant yeast Hsp90 with an IC50 of 143 ± 23 nM in the presence of 400 μM ATP. This compound has demonstrated anti-proliferative effects across a range of human cancer cell lines, including a notably low GI50 of 32.7 ± 0.2 nM in CH1 human ovarian cells, and an average GI50 of 78 ± 15 nM. It also inhibits the proliferation of human umbilical vein endothelial cells (HUVEC) with a GI50 of 19 ± 2.4 nM, while exhibiting higher GI50 values in non-tumorigenic human breast (MCF10a) and prostate (PNT2) epithelial cells. The cellular activities of VER-50589, which include causing cell cycle arrest and cytostasis in HCT116 colon cancer cells, do not depend on NQO1 expression and have been observed to lead to significant drug accumulation in these cells^[1].