[Alpha interferon in the therapy of hairy cell leukemia. Results of 3 prospective multicenter studies in West Germany].
Within 19 months of recruitment 51 centers enrolled 84 patients in our prospective multicenter trial for low-dose IFN alpha-2c for HCL (1.2 x 10 IU/m x 28 days s.c.- or lower). Induction therapy of 84 days was followed by maintenance with 2 weekly doses. Patients who reached stage Jansen I or A were then randomized to 2 arms either to receive further IFN or to stop treatment. Reinduction was reinstituted whenever any patient lost Jansen stage A or I. Only 3 patients failed. But enrollment was discontinued when it became apparent that fatalities in splenectomized (SX) patients due to septicemia outnumbered deaths given in the literature. Low-dose IFN administered daily might compromise host defense. Our next study aimed at improving the safety of IFN for SX patients. Pulsatile IFN on 7 consecutive days within a 28-day period was given to all SX patients. A randomization of non-SX patients either to receive daily or pulsatile IFN should provide proof of the efficiency. The intermissions ought to be as suitable for in-vitro investigations as for observations concerning the capacity of IFN to produce 'induction of inducers'. Pulsatile treatment has so far been safe in 13 splenectomized patients. Central diagnostic procedures remained the same during both studies. It seems important to us to use an intermittent schedule for the injection of IFN in SX patients and to restrict splenectomy to selected patients.