Definition

An orally bioavailable Salmonella-based survivin vaccine composed of a weakened form of a live strain of Salmonella bacteria (CVD908ssb strain) that has been genetically modified to produce the tumor-associated antigen (TAA) survivin, with potential immunopotentiating and antineoplastic activities. Upon administration of the CVD908ssb-TXSVN vaccine, the expressed survivin stimulates the immune response to elicit a cytotoxic T-lymphocyte (CTL)-mediated immune response against survivin-expressing cancer cells, resulting in a decrease in tumor cell proliferation and an induction of tumor cell death. Survivin, a member of the inhibitor of apoptosis (IAP) family expressed during embryonic development, is upregulated in a variety of human cancers while absent in most normal adult cells; its expression in tumors is associated with a more aggressive phenotype, decreased survival, and increased resistance to chemotherapy.