A Five-Arm, Open-Label, Phase I/Lb Study To Assess Safety And Tolerability Of The Oral Mek1/Mek2 Inhibitor Trametinib (Gsk1120212) In Combination With Chemotherapy Or Erlotinib In Patients With Advanced Solid Tumors.

3023 Background: Trametinib, an oral MEK1/MEK2 inhibitor, has demonstrated single-agent clinical activity. In vitro studies of trametinib plus docetaxel (doc), pemetrexed (pem) and erlotinib (erl) showed enhanced growth inhibition of lung cancer cell lines with and without RAS/RAF mutations. Trametinib+doc significantly increased apoptosis compared with either agent alone. Methods: This is a two-part, five-arm, phase I/Ib, open-label study to evaluate the safety and tolerability of trametinib plus doc, erl, pem, pem+carboplatin (pem+carbo), or nab-paclitaxel (nab-pac) (NCT01192165). Part I is dose escalation in patients (pts) with advanced solid tumors; part II is dose expansion in pts with lung and pancreatic cancers. A 3+3 dose-escalation design was used to determine the maximum tolerated dose (MTD) and the recommended phase II regimen (RP2R) for each combination. Dose-limiting toxicities (DLTs) were determined during the first treatment cycle (21 days). Trametinib was started at 0.5 mg/day; chemotherap...