After the fourth protocol amendment two study arms are evaluated in this clinical protocol: PD-0325901 (oral MEK inhibitor) plus PF-05212384 (intravenous PI3K/mTOR inhibitor) and PF-05212384 plus irinotecan. The study will assess safety, pharmacokinetics and pharmacodynamics of these combinations in patients with advanced cancer. Once the maximum tolerated doses are identified, further assessment of these combinations will be done in patients with previously treated metastatic colorectal or pancreatic cancer for the PF-05212384 plus irinotecan arm and in patients with ovarian cancer or KRAS mutated non small cell lung cancer for the combination of PF-05212384 plus PD-0325901.