Open-Label Study of Oral CEP-701 (Lestaurtinib) in Patients With Polycythemia Vera or Essential Thrombocytosis

Inclusion Criteria:

* The patient has polycythemia vera (PV) or essential thrombocytosis (ET).
* The patient has a detectable JAK2 V617F mutation.
* Patients with PV have at least 1 of the following risk factors:

  1. neutrophil count greater than 7000/mm3
  2. receiving hydroxyurea treatment
* Patients with ET are receiving concomitant hydroxyurea.
* The patient has an ECOG performance score of 0, 1, or 2.

Exclusion Criteria:

* The patient has bilirubin levels or aspartate transaminases (AST) levels within exclusionary ranges.
* patient has serum creatinine concentrations within exclusionary ranges.
* patient has an untreated or progressive infection.
* patient has any physical or psychiatric condition that may compromise participation in the study.
* has a history of venous or arterial thrombosis within 6 months.
* use of hydroxyurea has been initiated or escalated in the month prior to screening.
* has active gastrointestinal ulceration or bleeding.
* patient has used an investigational drug within the past 30 days.
* patient is being treated with anagrelide.
* patient has previously taken CEP-701 (lestaurtinib).
* patient has hypersensitivity to CEP-701 (lestaurtinib) or any component of CEP-701 (lestaurtinib).
* patient has received interferon within the past 30 days.