Synthetic polyribonucleotides: current role and potential use in oncological practice

Polyadenylic-polyuridylic acid (PAPU) has a wide range of effects on various immunological cells and functions. It has been shown to enhance cellular and humoral immunity, in particular anti-cancer host defences, in both animals and man. In a small number of clinical trials (breast and stomach cancers) it appears to have a beneficial adjuvant effect, in terms of prolongation of disease-free and overall survival. Side effects with PAPU are minimal. The precise mode of action of PAPU is unclear and the most beneficial therapeutic regimen has yet to be established. PAPU, therefore, merits further careful consideration and evaluation. This article reviews its present status and considers further priority areas for investigation.