The present invention provides a method for the treatment of interferon resistant bladder tumors through the use of a non-replicating agent which induces human cells to express interferon species. In particular it is noted that inducing interferon expression in the patient's body possesses properties not associated with recombinant produced, intravenously-administered interferon proteins. The present invention further provides compositions useful in the treatment of bladder cancer resistant to treatment with intravenous interferon polypeptide, by using a non-replicating agent which induces human cells to express interferon species, e.g., an antigenic, replication-deficient virus optionally carrying an interferon transgene.
