nivolumab + botulinumtoxinA

**Nivolumab + botulinumtoxinA** is an investigational combination therapy pairing nivolumab, a fully human IgG4 monoclonal antibody that inhibits the programmed cell death protein 1 (PD-1) checkpoint to enhance T-cell mediated antitumor immunity, with botulinumtoxinA (BoNT/A1), a neurotoxin that cleaves SNAP-25 to inhibit neurotransmitter release and may modulate the tumor microenvironment by reducing immunosuppressive signals or altering tumor hypoxia. Preclinical studies in mouse models of melanoma and colon carcinoma have demonstrated synergistic antitumor effects, improving responses beyond PD-1 blockade alone, potentially through complementary mechanisms like enhanced immune cell infiltration or reduced tumor-promoting inflammation. No clinical trials or approvals have been identified for this specific combination as of available data.