RECOMBINANT INTERFERON-ALFA 2A IN THE TREATMENT OF PATIENTS WITH EARLY STAGE-B CHRONIC LYMPHOCYTIC-LEUKEMIA

18 patients with early stage, previously untreated B-CLL were given in terferon alfa (IFNalpha) 2a, 3 MU thrice weekly, subcutaneously. The p eripheral lymphocyte count decreased in all patients. Response was del ayed in three patients until they had received a median of 5 months th erapy, one of whom had an initial transient increase in lymphocytes. T wo patients normalized their blood lymphocyte counts, but neither achi eved complete remission (CR). Responses were transient in eight patien ts lasting a median of 5 months (3-21). Binding anti-IFNalpha antibodi es were present in 9/17 patients tested (53%). Low titre binding antib odies (< 533 IBU/ml) were not associated with LHR, but high titre anti bodies (>4401 IBU/ml) were. Two of 12 patients assessed had a > 3 g/l increase in baseline serum IgG levels during IFNalpha therapy, one of whom reverted to pretreatment levels in association with LHR. Haematol ogical toxicity was moderate, other than in two patients, one of whom developed autoimmune haemolytic anaemia and the other thrombocytopenia . We conclude that IFNalpha lowers the lymphocyte count in early stage CLL, that the response may be delayed and that anti-IFNalpha antibodi es may play a role in a proportion of those in whom the response is tr ansient.