Ad-p53 + nivolumab

Ad-p53 + nivolumab is a combination investigational therapy being studied mainly for cancer treatment, in particular recurrent head and neck squamous cell carcinoma (HNSCC) and small cell lung cancer. **Ad-p53** is a replication-defective adenoviral vector encoding wild-type human p53 tumor suppressor protein, administered via intra-tumoral injection. p53 acts primarily by restoring tumor suppressor activity in p53-mutant cancer cells, leading to cell cycle arrest, apoptosis, and enhanced immune activation in the tumor microenvironment. **Nivolumab** is a fully human IgG4 monoclonal antibody targeting programmed death-1 (PD-1), a negative regulatory checkpoint on T cells, thereby blocking inhibitory signaling and enabling T cell-mediated anti-tumor response. The combination is being explored to potentiate immune checkpoint blockade efficacy, based on preclinical data that Ad-p53 can reverse resistance to anti-PD-1 therapies and enhance immune infiltration and activation within tumors.