3007 Background: Everolimus (E), an oral derivative of rapamycin, inhibits mTOR, a protein kinase downstream of PI3K and Akt, involved in the regulation of cell growth, proliferation and survival. In preclinical models, the administration of E is associated with reduction of mTOR downstream phosphorylated(p)-S6 (p-S6) and p-4E-BP1, and occasionally with increase in upstream p-Akt. This study explores safety, PK and MPD changes in tumor at different doses and schedules of E to define the recommended dose for further development. Methods: Pts with advanced solid tumors were treated in successive cohorts of E: weekly 20, 50 and 70 mg or daily 5 and 10 mg. Dose escalation depended on dose limiting toxicity (DLT) rate during the first 4-week period. Pre- and on-treatment steady-state (24hr post-dose and, for the weekly schedule, 5 days post-dose) tumor biopsies were obtained from each pt. Tumor tissue was evaluated by immunohistochemistry (IHC) for p-S6, p-4E-BP1 and p-Akt expression by a pathologist blinded f...