If you are found to be eligible to take part in this study, you will be assigned to a dose of CT-2103. Participants in this study will be enrolled in groups of 3. The first group will receive the lowest dose of CT-2103. Each new group of patients will receive a higher dose until the highest safe dose is found. The dose that you receive will depend on how many patients have received CT-2103 before you. You will only be assigned to one dose level, and you will stay at this same dose level for the entire study unless you have a serious side effect that requires the dose to be decreased or stopped. All participants will receive the same dose of gemcitabine, though it too may be lowered if severe side effects occur.