Purpose: This phase II study evaluated the efficacy and tolerability of onvansertib, a polo-like kinase 1 (PLK1) inhibitor, in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI) + bevacizumab for the second-line treatment of -mutant metastatic colorectal cancer (mCRC).
Patients And Methods: This multicenter, open-label, single-arm study enrolled patients with -mutated mCRC previously treated with oxaliplatin and fluorouracil with or without bevacizumab. Patients received onvansertib (15 mg/m once daily on days 1-5 and 15-19 of a 28-day cycle) and FOLFIRI + bevacizumab (days 1 and 15).
Occurrence of resistance to olaparib, a poly(ADP-ribose) polymerase (PARP) inhibitor (PARPi) approved in ovarian carcinoma, has already been shown in clinical settings. Identifying combination treatments to sensitize tumor cells and/or overcome resistance to olaparib is critical. Polo-like kinase 1 (PLK1), a master regulator of mitosis, is also involved in the DNA damage response promoting homologous recombination (HR)-mediated DNA repair and in the recovery from the G2/M checkpoint.
View Article and Find Full Text PDFPolo-like kinase 1 (PLK1) inhibitors have had limited antitumor efficacy as single agents, and focus of current efforts is on combination therapies. We initially confirmed that the PLK1-specific inhibitor onvansertib (ONV) could enhance responses to a PARP inhibitor (olaparib) in prostate cancer xenografts. To identify more effective combinations, we screened a library of bioactive compounds for efficacy in combination with ONV in LNCaP prostate cancer cells, which identified a series of compounds including multiple AKT inhibitors.
View Article and Find Full Text PDFPurpose: Onvansertib is a highly specific inhibitor of polo-like kinase 1 (PLK1), with demonstrated safety in solid tumors. We evaluated, preclinically and clinically, the potential of onvansertib in combination with chemotherapy as a therapeutic option for KRAS-mutant colorectal cancer.
Patients And Methods: Preclinical activity of onvansertib was assessed (i) in vitro in KRAS wild-type and -mutant isogenic colorectal cancer cells and (ii) in vivo, in combination with irinotecan, in a KRAS-mutant xenograft model.