A Study to Determine the Safety and Efficacy of Imatinib Mesylate in Patients With Idiopathic Hypereosinophilic Syndrome

A Study to Determine the Safety and Efficacy of Imatinib Mesylate in Patients With Idiopathic Hypereosinophilic Syndrome

The objectives of the study are:

1. Evaluation of the safety profile of imatinib mesylate in patients with idiopathic hypereosinophilic syndrome resistant or refractory to, or intolerant of, prednisone, hydroxyurea or interferon-alpha, or untreated patients carrying the Fip1L1-PDGFRA fusion protein.
2. Evaluation of the efficacy of imatinib mesylate in patients with idiopathic hypereosinophilic syndrome
3. Analysis of patient's blood samples for the detection of activated kinases.

Inclusion Criteria:

Idiopathic hypereosinophilic syndromes are included provided they belong to one of the following categories:

1. previously treated and showing documented resistance or refractoriness to, or intolerance of, prednisone, hydroxyurea or interferon-alpha.
2. not previously treated but with documented Fip1L1-PDGFRA fusion protein

Exclusion Criteria:

• Other diseases associated with hypereosinophilia
• Serum creatinine, serum bilirubin, AST, ALT more than twice the upper normal limit.
• ECOG performance status >3

Other protocol-defined exclusion criteria may apply.