Study of Safety and Tolerability of PCI-27483 in Patients With Pancreatic Cancer Patients Receiving Treatment With Gemcitabine

This study will be conducted in three segments: Part A, Part B and Part C. Parts A and B are 12 weeks of treatment followed by 4 weeks of evaluation. In part A patients will dose-escalate up to three dose levels of PCI-27483 administered as subcutaneous (SC) injections twice-daily (BID). Part B to start once 4th patient completes 90 of 112 doses in 8 weeks. In part B patients are randomized to PCI-27483 and gemcitabine (active arm) OR gemcitabine only (control arm). PCI-27483 doses in both Part A and B will be administered in combination with a standard regimen of gemcitabine. Patients with a tumor response or stable disease at 12 weeks will have the opportunity to continue PCI-27483 treatment until disease progression or the Investigator considers the study treatment to be no longer tolerable. Treatment with gemcitabine in either the active or control arm may continue until a standard course of gemcitabine therapy has been completed. Patients will complete Part A or Part B after 16 weeks on study regardless of treatment duration. Evaluable patients will roll over into part C and be followed for 12 months from enrollment (first dose).