BRAF/MEK/EGFR Inhibitor Combination Study in Colorectal Cancer (CRC)

Part 1: Dose escalation This was a dose escalation part intended to evaluate safety, tolerability, PK, PD, clinical activity and determine RP2R/MTD for the doublet (D+P) and the triplet (D+T+P) combinations in patients with BRAF-mutation V600E positive advanced or metastatic CRC. A 3+3 dose escalation procedure was followed. Dosing for dabrafenib and trametinib was continuous daily dosing while panitumumab was dosed once every two weeks (Q2W). Patients were evaluated for dose-limiting toxicities (DLTs) during the first 28 days of treatment. Part 2A: This was a cohort expansion part to assess the safety and preliminary clinical activity of the optimal safe and tolerable dose combinations (D+P)/(D+T+P) defined in Part 1. Part 2B: In this part, additional patients were enrolled into the triplet (D+T+P) combination at two dose levels in to further explore safety, tolerability and clinical activity. Up to 10 patients each with no prior treatment (First Line Population), and up to 20 patients each with at least one prior treatment (Second to Fourth Line Population) were planned to be enrolled in dose Cohorts 3A and 4. Part 3: Randomized Phase 2 Study The randomized phase 2 portion (Phase 3) of the study was not pursued as the observed responses in any of the cohorts did not meet the predefined criteria at the time of the preliminary analysis (data cut-off date: 06-May-2016). Part 4 This part was designed to identify the RP2R/MTD and initial clinical activity for the doublet (T+P) combination in patients BRAF-mutation V600E positive advanced or metastatic CRC, and advanced or metastatic CRC with secondary resistance to prior anti-EGFR therapy. Part 4A: Dose Escalation This was a dose escalation part intended to determine RP2R/MTD for the doublet (T+P) combination in patients with BRAF-mutation V600E positive advanced or metastatic CRC. Approximately 18 patients (\~6 each cohort) were planned to be enrolled in Part 4A. A 3+3 dose escalation procedure was followed. Dosing for trametinib was continuous daily dosing while panitumumab was dosed once every two weeks (Q2W). Patients were evaluated for DLTs during the first 28 days of treatment. Part 4B: Cohort Expansion This was a cohort expansion part intended to evaluate safety and efficacy of the doublet (T+P) combination. Up to 20 patients in each of two expansion cohorts were planned to be enrolled at the starting dose cohort or MTD from Part 4A.