Chronic myelogenous leukaemia: haematological remissions with alpha interferon

Summary. Twenty‐seven consecutive patients with previously untreated, or minimally treated benign phase Philadelphia‐chromosome‐positive, chronic myelogenous leukaemia (CML) were treated with partially purified human leucocyte (alpha) interferon; 24 of the 27 patients responded to therapy achieving either haematological remission (20 patients) or partial haematological remission (four patients). In the responding patients the peripheral white blood cells declined from a median of 89.6 × 10 × 10⁹/1 to 4.5 × 10 × 10⁹/1. The serum lactate dehydrogenase declined from a mean of 8.36 Katal/1 (492 mu/ ml) to 2.8 Katal/1 (165 mu/ml), and the vitamin B₁₂ levels declined from 1492 pg/ml to 838 pg/ml. Fifteen patients had splenomegaly. The spleen size normalized in four and decreased by a median of 30% in 10 additional patients. The bone marrow cellularity fell from a median of 100% to a median of 62%. In seven of the 24 responding patients, followed for ≤ 6 months, the percentage of Ph¹‐positive cells in the bone marrow declined to a median of 70% (range 5–75%). Alpha interferon was found to be an effective therapeutic agent for controlling the myeloid proliferation in CML, and in partially restoring the nonclonal haematopoietic cells in some of the patients.