Phase I-II study of recombinant alpha-2 interferon against advanced leukemia and lymphoma in children

Alpha-2 interferon, produced in Escherichia coli using recombinant DNA techniques, was administered to 17 children with refractory acute lymphoblastic leukemia (ALL) in relapse, two children with TdT-positive, Philadelphia chromosome-positive chronic myelocytic leukemia (CML) in blast crisis, and one child with B cell (Slg+) non-Hodgkin's lymphoma (NHL) in a second extramedullary relapse. An initial 2-week intravenous (IV) phase of interferon was followed by a 3-month subcutaneous (SC) maintenance phase if patients had an objective response or disease stabilization without significant bleeding or infectious complications. When interferon dosages were escalated from 3 to 100 x 10⁶ U/m² in the first phase of therapy, there was rapid progression of disease in the first four patients treated, prompting a modification of the treatment plan. The last 16 patients enrolled received fixed dosages of interferon (ie, 10, 20, 30, and 50 x 10⁶ U/m² administered to four subjects each). One child with T cell ALL had an 11-month complete remission; the patient with lymphoma had a dramatic but brief response; three others (one CML and two ALL) showed disease stabilization for 3 to 6 months with a definite oncolytic effect in two of the three patients. The remaining 15 patients had progressive disease within 2 months and were removed from the study. Acute toxicity included a flu-like syndrome in all patients, increased serum transaminase levels in five, seizures in three (two cases temporally related to fever and one to a thrombocytopenic subarachnoid hemorrhage), and prolonged activated partial thromboplastin times in seven. This phase I-II trial of recombinant alpha-2 interferon demonstrated definite activity without dose-limiting toxicity.