An oncolytic adenoviral vaccine composed of a replication-defective, E1- and E3-deleted adenovirus serotype 5 (Ad5) with a transgene encoding the human melanoma antigen A3 (MAGE-A3), with potential antineoplastic activity. Upon administration, MAGE-A3-expressing adenovirus type 5 vaccine selectively replicates in cancer cells and expresses MAGE-A3. This induces an immune response against tumor cells expressing the MAGE-A3 antigen, which leads to tumor cell death. The tumor-associated antigen MAGE-A3 is overexpressed by a variety of cancer cell types. [ ]