Effect Of Interferon-Alpha-2b On The Enhancement Of Tumour Uptake Of Tc-99(M)-Labelled Monoclonal Antibodies

We have previously shown that certain biological response modifiers (BRMs) can significantly increase the tumour uptake of radiolabelled monoclonal antibodies (MAbs). Among the three different BRMs (Ukrain, Pokeweed mitogen and interferon) we evaluated, interferon gave us the best results. A series of experiments were conducted here to further elicit the influence of interferon on the enhancement of tumour uptake. Interferon-alpha-2b (IFN-alpha-2b) was used as a biological response modifier, human melanoma xenografts grown in athymic nude mice as a tumour model, and anti-human melanoma specific ME31.3 as the MAb. The MAb was labelled with technetium-99m by a direct labelling method. IFN-alpha-2b was administered in different doses via intravenous, intramuscular or intratumoral routes. The results showed a significant (P less than or equal to 0.05) increase in absolute tumour uptake of radiolabelled ME31.3 in all IFN-alpha-2b-treated groups. The maximum increase (from 2.0 +/- 1.4% in the control group to 7.2 +/- 1.2% in the experimental group, P < 0.01) was obtained when 20K international units of IFN-alpha-2b were injected intramuscularly.