A Study in Myeloproliferative Disorders

The purpose of the study is to learn: 1. How much and how often LY2784544 should be given to patients 2. What is the safety profile of LY2784544 and any side effects that might be associated with it 3. How LY2784544 is taken up, distributed, broken down, and passed out of your body 4. Whether LY2784544 can help patients with myeloproliferative disorders 5. If any markers in the blood (biomarkers) can identify patients who will respond better to the study drug. The planned duration of the study is not fixed. The length of time patients participate in the study will be determined by the investigator/study doctor. Part A of the study is to determine the dose of the study drug. Part A is divided into two sections, A1 and A2. In Part A1, patients will be given study drug without a lead-in period. In Parts A2 and B, patients will have a lead-in period of 2 or 4 weeks with a low dose of LY2784544 prior to taking a higher dose of LY2784544. Part B of the study is to confirm the safety of the dose and schedule.