Abstract
PURPOSE: This "3+3" phase I study evaluated the safety, biologic, and clinical activity of lenvatinib, an oral multikinase inhibitor, in patients with solid tumors. EXPERIMENTAL DESIGN: Ascending doses of lenvatinib were administered per os twice daily in 28-day cycles. Safety and response were assessed for all patients. Angiogenic and apoptotic factors were tested as possible biomarkers in an expanded melanoma cohort. RESULTS: Seventy-seven patients were treated in 3 cohorts: 18 with intermittent twice-daily dosing (7 days on, 7 days off) of 0.1-3.2 mg; 33 with twice-daily dosing of 3.2-12 mg; and 26 with twice-daily dosing of 10 mg (expanded melanoma cohort). Maximum tolerated dose was established at 10 mg per os twice daily. Prominent drug-related toxicities included hypertension (43%), fatigue (42%), proteinuria (39%), and nausea (25%); dose-limiting toxicities included hypertension, fatigue, and proteinuria. Twelve patients (15.6%) achieved partial response (PR, n = 9) or unconfirmed PR (uPR, n = 3), and 19 (24.7%) achieved stable disease (SD) ≥23 weeks. Total PR/uPR/SD ≥23 weeks was 40.3% (n = 31). Responses (PR/uPR) by disease were as follows: melanoma, 5 of 29 patients (includes 1 patient with NRAS mutation); thyroid, 3 of 6 patients; pancreatic, 1 of 2 patients; lung, 1 of 1 patients; renal, 1 of 1 patients; endometrial, 1 of 4 patients; and ovarian, 1 of 5 patients. AUC(0-24) and C(max) increased dose proportionally. In multivariate Cox proportional hazard model analyses, increased baseline systolic blood pressure and decreased angiopoietin-1 ratio (2 hours:baseline) were associated with longer progression-free survival (PFS) in the expanded melanoma cohort (P = 0.041 and P = 0.03, respectively). CONCLUSIONS: The toxicity profile, pharmacokinetics, and antitumor activity of lenvatinib are encouraging. Decreases in the angiopoietin-1 ratio correlated with longer PFS in melanoma patients.