Alpha-Interferon in Hematological Disorders with Special Emphasis on Chronic Myeloid Leukemia

A phase II European Organisation for Research on Treatment of Cancer (EORTC) study was started in 1985 to assess the activity of recombinant interferon-α2c (rIFN-α2c). Sixty-two chronic myeloid leukemia (CML) patients were studied. A dose of 3 × 106 units (3MU) was given once daily i.m. It was progressively increased up to 5, 10, or 15 MU according to response and tolerance. Induction treatment lasted 6–16 weeks. Patients reaching hematological response (HR) received maintenance IFN-a for 3 years or until progression of the disease. Our results in general confirm those of others [1]. IFN-a produced HR in 75% of previously untreated patients. Chemotherapy prior to IFN-a had a negative impact. Indeed, the response rate to IFN-a decreased to 58% in 27 patients still responsive to chemotherapy and to 44% in 9 treated but resistant. A decrease of percentage Philadelphia chromosome-positive (%Ph+) mitosis as a consequence of IFN-a was seen in 40% of the previously untreated patients and was virtually absent in previously treated patients. The survival from start of IFN-a therapy also was significantly better in patients receiving IFN-a as first treatment (n = 25). In the group of patients below 45 years of age, never treated before and responding to INF-a (n = 25), the survival is still 100%.