Interferon-alpha-2C in the treatment of advanced hairy cell leukaemia. Results of a phase II trial.

The efficacy of recombinant interferon-alpha 2 in the treatment of advanced hairy cell leukaemia is investigated in 31 patients. Preliminary results show a complete and partial response rate of 69%. An optimal dose study utilizing maximal stimulation of an interferon-dependent pathway was carried out in 5 patients. The optimal dose of the order of 5 X 10(5) IU/day is effective and without side-effects. Interferon treatment did not enhance natural killer cell activity and therefore a direct mode of action upon tumour cells is proposed.