A phase 1 study of linifanib in combination with carboplatin/paclitaxel as first-line treatment of Japanese patients with advanced or metastatic non-small cell lung cancer (NSCLC)

Linifanib is a potent, orally active, and selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor kinase activities with clinical efficacy in non-small cell lung cancer (NSCLC). This phase 1 dose-escalation study evaluated the pharmacokinetics, safety, and efficacy of linifanib in combination with carboplatin/paclitaxel in Japanese patients with advanced NSCLC. Carboplatin (AUC = 6 mg/mL/min) and paclitaxel (200 mg/m(2)) were administered on day 1 of each 21-day cycle up to a maximum of six cycles. Oral linifanib (7.5 mg) was given to six patients once daily throughout all cycles and escalated to 12.5 mg/day in a second cohort of six patients. Twelve patients received at least one dose of linifanib. The most common adverse events were hematologic and consistent with expected toxicities with carboplatin/paclitaxel. With 12.5 mg linifanib, grade 3/4 neutropenia, leukopenia, and thrombocytopenia occurred in 100, 83, and 83 % of patients, respectively. Dose-limiting grade 4 thrombocytopenia occurred in one patient at each dose level. Linifanib pharmacokinetics was similar to that in non-Japanese patients. At 12.5 mg, linifanib C (max) was 0.32 mu g/mL and AUC(24) was 4.29 mu g h/mL. Linifanib C (max) occurred at 2-3 h with both doses and when given alone or in combination with carboplatin/paclitaxel. Exposure to linifanib appeared to be increased by carboplatin/paclitaxel, and exposure to paclitaxel appeared to be increased by linifanib. Partial responses were observed in nine patients. Linifanib added to carboplatin/paclitaxel is well tolerated in Japanese patients with advanced/metastatic NSCLC. The recommended dose of linifanib with carboplatin/paclitaxel is 12.5 mg, same as for US patients.