Interferon-alpha induced changes in CEA expression in patients with CEA-producing tumours

Enhancement of antigen expression could result in improved tumour targeting using antibodies directed to the antigen. In this study we performed radio immunoscintigraphy using Tc-99m-CEA-Scan to analyse the effect of interfero n-alpha (IFN-alpha) in enhancing the expression of carcinoembryonic antigen (CEA) in ten patients with CEA-producing tumours, Furthermore, we investig ated the feasibility of a future therapeutic Study with this antibody fragm ent labelled with rhenium-186, Although IFN-alpha gave rise to a significan t increase in antibody uptake by the tumour, the absolute antibody uptake i n the tumour appeared to be poor, with a mean of 0.475% of injected dose (T D) in the tumour before IFN-alpha, rising to 0.562%, LD in the tumour after IFN-alpha. Pharmacokinetic analysis demonstrated no significant alteration s after IFN-alpha, In conclusion, the administration of IFN-alpha is an att ractive way to achieve enhanced tumour targeting, although the increase was of little clinical significance in this patient population and using this antibody fragment.