The Effect of Interferon-Alpha on the Activity of Cytotoxic Drugs in Bronchial Carcinoma Xenografts

Two human non-small cell lung cancer xenograft lines were used to study the activity of combina tions of 2 cytotoxic drugs with human alpha-2 interferon. Statistically significant potentiation of cisplatin and ifosfamide given weekly for 5 weeks in a low dose was seen when recombinant human alpha interferon (rHu IFN-alpha 2b) was administered simultaneously (2×104 U/mouse/day). Median doubling time for cisplatin treated tumours increased from 17 and 14 days to 27 and 18.5 days with the addition of interferon, whereas for ifosfamide they increased from 11.5 and 14 days to 15 and 16 days. Human alpha-2 interferon at this dose had no effect as a single agent.