Derudover fremkaldte ribavirin ikke tumorer i en 26 ugers carcinogenicitetsundersøgelse med den heterozygote p53( + / -) musemodel og den maksimalt tolererede dosis på 300 mg/ kg (plasma ekspositionsfaktor cirka 2, 5 sammenlignet med human eksponering).
In addition, in a 26 week carcinogenicity study using the heterozygous p53(+/ -) mouse model, ribavirin did not produce tumours at the maximally tolerated dose of 300 mg/ kg (plasma exposure factor approximately 2.5 compared to human exposure).