[Clinical efficacy of Z-100 for the treatment of leukopenia caused by radiotherapy--a multi-center double-blind comparative study with inosine].

The clinical usefulness and the optimal dose of Z-100 for the treatment of leukopenia caused by radiotherapy for malignant tumors was evaluated in a double-blind study comparing 20 micrograms and 30 micrograms injections of Z-100 and inosine (Z-20, Z-30 and IN group, respectively). The effective rate according to the evaluation by the attending physicians was 67.4%, 79.1% and 48.9% in the Z-30, Z-20 and IN groups, respectively, with a significantly higher efficacy rate for the Z-20 group than for the IN group. The frequency of adverse reactions was 14.3%, 3.9% and 5.6% in the Z-30, Z-20 and IN groups, respectively, with the highest rate in the Z-30 group, but there was no significant difference among the three groups. The useful rate based on total evaluation considering the effective rate and the safety profile in each group was 60.8%, 77.3% and 46.8% in the Z-30, Z-20 and IN groups, respectively, with the highest rate in the Z-20 group showing significant difference from that in the IN group. The above data confirmed the clinical usefulness of Z-100 and suggested that the optimal dose was 20 micrograms twice weekly for Z-100.