Efficacy and safety of oral MEK162 in patients with locally advanced and unresectable or metastatic cutaneous melanoma harboring BRAFV600 or NRAS mutations.

8511 Background: BRAF and NRAS mutations occur in 50-60% and 15-20% of cutaneous melanomas, respectively. MEK162, a selective inhibitor of the kinases MEK1 and MEK2, has shown pre-clinical activity in BRAF and NRAS mutant (mt) melanoma models. This open label, phase II study assessed the antitumor activity of MEK162 in patients (pts) with BRAFV600 and NRAS mt advanced cutaneous melanoma. Methods: MEK162 was administered orally at a starting dose of 45 mg twice daily. Treatment was until unacceptable toxicity, disease progression (PD) or investigator or patient refusal. Tumor response was assessed by CT imaging every 8 weeks (RECIST 1.0) until PD. Results: As of 16 Sept 2011, the full analysis and safety populations comprised 66 pts: 42 BRAF mt and 24 NRAS mt. Median age 58.0 years; 57.6% male; 72.7% WHO performance status 0. All NRAS pts and all but 2 BRAF (1 each stage IIIB and IIIC) pts had stage IV disease, and 87.5% of NRAS pts and 66.7% of BRAF pts had received prior therapy at study entry. Median ti...