A phase II study of the multitargeted kinase inhibitor lenvatinib in patients with advanced BRAF wild-type melanoma.

9026 Background: Lenvatinib is an oral receptor tyrosine kinase inhibitor targeting VEGFR1-3, FGFR1-4, RET, KIT, and PDGFRβ. Melanoma responses in the phase I study led to this multicenter phase II trial of lenvatinib in separate cohorts of BRAF mutant and BRAF wild-type (wt) melanoma to provide an estimate of efficacy and to identify molecular correlates of clinical benefit. Primary analyses of clinical outcomes for the BRAF wt cohort are reported here; the BRAF mutant cohort will be presented at a later date. Methods: Eligible patients (pts) had stage IV or unresectable stage III BRAF wt melanoma with ≥1 prior treatment (26/96 [27%] pts received ≥3 treatments) and no prior VEGF-targeted therapy. Lenvatinib 24 mg once daily with dose reduction for toxicity was administered until disease progression or unmanageable toxicities. Primary endpoint was response rate by independent review (IRR) using RECIST 1.1. Archival tumor tissue and baseline and posttreatment serum samples were collected for molecular analysis. Results: 93 pts were treated (median [m] age: 64 y; male: 69%; 95% AJCC stage IV). Confirmed partial responses (PRs) were observed in 8 pts (9%) with a clinical benefit rate (CR+PR+durable SD ≥23 wks) of 32% by IRR. mPFS was 3.7 mos (95% CI, 2.5-4.0) by IRR and mOS was 9.5 mos (95% CI, 8.3-12.9); 46% pts required dose reduction for management of toxicity; 12% were withdrawn from therapy due to toxicity. Treatment-related adverse events reported in ≥20% pts included hypertension 59% (34% Gr 3/4), fatigue 58% (16% Gr 3/4), nausea 44% (3% Gr 3/4), diarrhea 43% (2% Gr 3/4), decreased appetite 38%, vomiting 29% (2% Gr 3), dysphonia 27%, and proteinuria and headache 26% each (4% and 1% Gr 3/4). Serum biomarker analysis showed baseline levels of serum angiogenic factors, such as angiopoietin-2, correlated with OS. More extensive biomarker analyses are reported in an accompanying abstract. Conclusions: Lenvatinib administered to pts with advanced BRAF wt melanoma was associated with frequent but manageable toxicity. Clinical benefit was seen in some pts. Predictive biomarkers for response to lenvatinib, such as the serum level of angiogenic factors, may be useful for future clinical trials. Clinical trial information: NCT01136967.