Phase I study of recombinant leukocyte A human interferon combined with BCNU in selected patients with advanced...

Interferons manifest diverse immunomodulatory and antiproliferative characteristics. Since their spectrum of toxicities includes primarily fatigue and anorexia rather than the myelosuppression concomitant with cytotoxic therapies, it is conceptually appealing to combine both modalities. We conducted a phase I trial among 18 patients using the combination of leukocyte A recombinant interferon (IFN-rA) and BCNU. The intramuscular (IM) IFN-rA dose for the initial 12 patients was 12 X 10(6) U/m2 three times a week for an anticipated duration of 12 weeks. Among these patients, we escalated the monthly intravenous (IV) BCNU dose from 50 mg/m2 to 150 mg/m2. Six subsequent patients received IFN-rA 12 X 10(6) U/m2, days 1 to 3, and BCNU 150 mg IV on day 3 of each monthly cycle. Dose-limiting toxicities from both regimens were fatigue and myelosuppression. We recognize the limitation of small sample sizes. Nevertheless, in the absence of a significant number of life-threatening toxicities, it appears that near maximal doses of BCNU and concomitant IFN-rA can be administered with safety in an outpatient setting.