A replication-deficient recombinant adenovirus encoding human interferon alpha-2b with potential antineoplastic activity. Upon intravesical administration, recombinant adenovirus-interferon SCH 721015 infects nearby tumor cells and expresses INF alpha-2b intracellularly which activates the transcription and translation of genes whose products mediate antiviral, antiproliferative, antitumor, and immune-modulating effects.