52P MUC1 targeted immunotherapy with an oncolytic adenovirus coding for a bispecific T cell engager

Bispecific T cell engager (BsTe) is a fusion recombinant protein comprised of two single–chain variable fragments with dual specificity for a tumor–associated antigen (TAA) and T cell receptor (usually CD3ε). Immunotherapy with BsTe has shown efficacy in patients with hematologic malignancies and uveal melanoma. However, the antitumor efficacy of BsTe in most solid tumors has been limited due to their short serum half-life and insufficient tumor concentration. We designed a novel serotype 5/3 oncolytic adenovirus encoding for a BsTe cross-linking Mucin1 (MUC1) to CD3, Ad5/3–E2F–d24–aMUC1aCD3.