- To evaluate failure-free survival of patients with newly diagnosed peripheral T-cell non-Hodgkin lymphoma treated with cyclophosphamide, doxorubicin hydrochloride, vincristine, prednisone (CHOP), and denileukin diftitox (Ontak®) alternating with high-dose methotrexate, leucovorin calcium, cytarabine, and Ontak® (CHOP-MONTAK regimen).