First-in-human phase i trial of two schedules of OSI-930, a novel multikinase inhibitor, incorporating translational proof-of-mechanism studies

Purpose: OSI-930 is a novel, potent, oral small-molecule receptor tyrosine kinase inhibitor, predominantly against VEGF receptors (VEGFR), c-Kit, and platelet-derived growth factor receptors. A phase I trial was undertaken to determine safety, maximum-tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and antitumor activity of OSI-930 in patients with advanced solid tumors. Experimental Design: OSI-930 was administered once or twice a day using a modified accelerated titration design. Pharmacokinetics and plasma soluble VEGFR2 (sVEGFR2) studies were undertaken. Dynamic contrast-enhanced MRI (DCE-MRI) and 2[18F]fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) MTD expansion cohorts were conducted. Results: Fifty-eight patients received OSI-930 in 2 schedules; once a day schedule: 12 patients at doses up to 1,600 mg without reaching MTD; twice a day schedule: 46 patients at 400 mg ( n = 7), 500 mg ( n = 31), and 600 mg ( n = 8). Dose-limiting toxicities were observed at 600 mg twice a day ( n = 3): G3 rash ( n = 2) and G4 γ-glutamyltransferase, establishing the MTD at 500 mg twice a day. Common G1–2 toxicities included fatigue, diarrhea, nausea, and rash. Antitumor responses were seen in 2 patients with advanced ovarian cancer [Response Evaluation Criteria in Solid Tumors (RECIST) partial response (PR) ( n = 1); GCIG CA125 response ( n = 1)]. Eleven of 19 heavily pretreated imatinib-resistant patients with gastrointestinal stromal tumors achieved RECIST stable disease (median duration: 126 days), with FDG-PET scans showing PRs in 4 of 9 patients. OSI-930 exposure increased with dose; substantial decreases in sVEGFR levels were observed with OSI-930 twice a day doses ≥400 mg, while DCE-MRI responses were shown in 4 of 6 patients. Conclusions: OSI-930 is safe and well tolerated, with pharmacokinetic–pharmacodynamic data supporting proof-of-mechanism with clinically relevant antitumor activity. Clin Cancer Res; 19(4); 909–19. ©2012 AACR .