[Interferon alfa-2B in chronic lymphatic leukemia of the B-cell type]

In a clinical phase II study nine patients (five men and four women; mean age 48 [42-58] years) in an early stage of chronic lymphatic leukaemia (CLL) of the B-cell type were treated with recombinant alpha-2b interferon (IFN alpha-2b), initially at a dosage of 5 mega units subcutaneously three times weekly, but in some cases reduced to 2.5 or raised to 10 mega units. Duration of treatment has been 15-36 months. Through-flow cytometry in seven patients demonstrated a definite fall in circulating B1-positive lymphocytes. Lasting partial remission (duration of 106-134 weeks) was achieved in four patients, in a further four the condition remained stable. A recurrence was noted in the patient with the initially highest lymphocyte count (52,000/microliters) after 28 weeks, control being achieved only after 64 weeks of chemotherapy. Side effects were flu'-like symptoms and (in two instances) depression. In three patients there was a clear rise in serum immunoglobulin concentrations as sign of IFN alpha-2b-induced increased immune response, while in four HLA-DR expression on monocytes was doubled. It is concluded that early treatment of CLL with IFN alpha-2b may delay the onset of necessary chemotherapy, any antibody-deficiency may be improved and survival time may ultimately be lengthened.