Preventive effects of interleukin 1 beta for ACNU-induced myelosuppression in malignant brain tumors: the experimental and preliminary clinical studies.

The effect of recombinant human interleukin 1 beta (rHuIL-1 beta) on myelosuppression induced by 3-[(4-amino-2-methyl-5-pyrimidynyl)methyl]-1-(2-chloroethyl)-1-nit rosourea hydrochloride (ACNU) was studied. In in vivo study using BALB/c mice, pretreatment with 1 microgram/mouse of rHuIL-1 beta as a single intraperitoneal (i.p.) injection had a significant preventive effect on thrombocytopenia as well as granulocytopenia induced by ACNU at an intravenous dose of 60 mg/kg. Facilitated recovery by rHuIL-1 beta administered seven days after injection of high-dose ACNU was also observed. Experimental combination immunochemotherapy with high-dose ACNU and rHuIL-1 beta was performed in nude mice inoculated with human glioblastoma subcutaneously. The elongation of the survival time of the tumor bearing nude mice was also observed in combined use of high dose ACNU with rHuIL-1 beta. Seven patients with malignant brain tumors received intravenous 2.5-3 mg/kg ACNU. All patients were subcutaneously injected with 2 x 10(4)-U or more rHuIL-1 beta twice a week or daily. The mean nadir of leukocyte, granulocyte, and thrombocyte counts of the 7 patients received 2.5-3 mg/kg ACNU were significantly higher than in matched historical controls. In combination with rHuIL-1 beta, it may be possible to use chemotherapeutic agents at a relatively high dose.