In vitro activity: PFK-158 is the first 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) inhibitor to undergo clinical trial testing in cancer patients. PFK-158, a small molecule therapeutic candidate that inactivates a novel cancer metabolism target never before examined in human clinical trials. PFK-158 is not only a first-in-class cancer drug but also the first to target glucose metabolism by inhibiting PFKFB3. PFK-158 is a nanomolar inhibitor of recombinant PFKFB3. PFK-158 inhibits PFKFB3 activity and glycolysis in cancer cells.

Kinase Assay: Since elevated glucose utilization in cancer supports lipogenesis at multiple levels13 and considering that it could be another contributing factor toward chemoresistance, it was checked whether PFK158 treatment could modulate lipid pathways. Results showed that the C13 and HeyA8MDR cells had more LDs compared to the chemosensitive cells (Fig.4 a and b) and PFK158 treatment significantly reduced the number of LDs in these cells (Fig4 c and d). Of interest, genetic downregulation of PFKFB3 in C13 and HeyA8MDR cells (Fig.4 e and g) also resulted in a reduction of LDs. The data indicates that PFK158 has synergistic antiproliferative effects in vitro when combined with cisplatin in C13 and HeyA8MDR cells compared to OV2008 and HeyA8, respectively (Fig. S3A‐C and E‐G, Supporting Information). PFK158 treatment induces lipophagy and also sensitizes chemoresistant cells to chemotherapy‐induced cytotoxicity both in vitro and in vivo. Importantly, this data also showed that inhibiting autophagy with BafA reverses the PFK158‐induced chemosensitivity to carboplatin more in the resistant than the sensitive cells. In conclusion, this is one of the first studies to show that PFK158, a specific inhibitor of PFKFB3, simultaneously targets both the glycolytic and lipogenic pathways, two pathways that are very active in cancer, and promotes lipophagy to inhibit tumor growth.

Cell Assay: PFK-158 is not only a first-in-class cancer drug but also the first to target glucose metabolism by inhibiting PFKFB3. PFK-158 is a nanomolar inhibitor of recombinant PFKFB3. PFK-158 inhibits PFKFB3 activity and glycolysis in cancer cells.