PRIMARY OBJECTIVES:~I. To determine the overall hematologic response rate to ruxolitinib in patients with hypereosinophilic syndrome and primary eosinophilic disorders.~SECONDARY OBJECTIVES:~I. To determine safety profile of ruxolitinib in patients with hypereosinophilic syndrome and primary eosinophilic disorders.~II. To determine the proportion of patients on corticosteroids who are able to become corticosteroid-independent and/or reduce the dose by >= 50%.~III. To evaluate the duration of response (DoR). IV. To evaluate the time-to-response (TTR). V. To evaluate progression-free survival (PFS) and overall survival.
This phase II trial studies how well ruxolitinib works in treating patients with hypereosinophilic syndrome or primary eosinophilic disorders.