Phase I study of oral S-1 in combination with oxaliplatin (oxali) and bevacizumab (bev) in patients with advanced solid tumors

4091 Background: S-1 is a novel oral fluoropyrimidine (tegafur, CDHP and potassium oxonate) designed for enhanced DPD inhibition and reduced GI toxicity. Bev and oxali have demonstrated safety and synergistic anti-tumor activity with oral and IV fluoropyrimidines. The primary objective is to investigate the safety and maximum tolerated dose (MTD) of S-1 combined with bevacizumab and oxaliplatin in patients with advanced solid tumors. Secondary objective is to investigate the clinical pharmacokinetics (PK) of the components of S-1 (FT, CDHP, Oxo), 5-FU, a-fluoro-β-alanine, cyanuric acid, uracil, and oxali and to document any antitumor activity. Methods: ECOG 0/1 patients with advanced or metastatic solid tumors received oral S-1 starting at 20 mg/m2/dose BID x 14 days (classic 3+3 cohort dose escalation by 5mg/m2/dose until MTD), plus fixed doses of bev 7.5 mg/kg IV day 1, and Oxali 130 mg/m2 IV day 1 of every 3 week cycle, with discontinuation of oxali after 4 cycles. Reintroduction of oxali was allowed u...