Personalizing cancer treatment of combined targeting of PI3K/AKT and MAPK pathways in advanced cancer patients harboring simultaneous oncogenic alterations in both signaling pathways.

e13025 Background: Frequent coactivation of both PI3K/AKT and MAPK pathways has been seen in a number of different tumor types. Preclinical studies also provide a clear rationale for the co-inhibition of these, "semi-parallel" pathways. Methods: We reviewed the records of 1,672 consecutive advanced cancer patients (pts) in our Phase I Clinical Trials Program and investigated the clinical impact of simultaneous blockade of both PI3K/AKT and MAPK pathways in patients with oncogenic alterations in both signaling pathways from 317 pts who received PI3K pathway inhibitor and/or MAPK pathway inhibitor. Results: 163 of 317 pts (51.4%) were tested for comprehensive tumor genomic analysis using DNA array-based CGH/PCR-based DNA sequencing. PI3K pathway genetic alterations (PIK3CA mutation, n=3; PTEN deletion, n=18; AKT amplification, n=10) were detected in 29 of the 163 (17.8%) pts. RAS/RAF pathway genetic alterations (KRAS mutation, n=33; HRAS mutation, n=4; BRAF mutation, n=6) were detected in 43 of the 163 (26....