What we are studying
The purpose of this study is to look at the effectiveness of giving participants who have been diagnosed with ET or PV one of two different study regimens over time. The study doctor would want to follow patients' condition for about 5 years. The study regimens are either ‘PEGASYS’ (or Pegylated Interferon Alfa-2a) or ‘Hydroxyurea’. All subjects participating in this study will also receive Aspirin as a part of their study regimen regardless of which study drug they will receive. More information on these study regimens will be described later in this information sheet. To enter this study patients may be a newly diagnosed subject or a subject already receiving treatment for either PV or ET. Each of the study drugs used in this study is already being used to treat subjects with ET or PV currently but we are unsure which study drug is better.