In total, 18.5% (79/428) of the evaluated cancers expressed LAG3, including pancreatic cancer (33.3%, 2/6), gastric cancer (24.7%, 21/85), colorectal cancer (23.6%, 48/203), melanoma (12.5%, 1/8), genitourinary cancer (9.5%, 4/46), biliary tract cancer (6.3%, 1/16), and sarcoma (5.4%, 2/37), but not miscellaneous (0.0%, 0/14) or hepatocellular (0.0%, 0/15) cancer.
We report 2 patients with BRAF V600 mutant melanoma who were previously treated with anti-PD-1±anti-LAG-3 antibodies and were switched to BRAF/MEK-inhibitors because of progressive disease.
Previously, we showed that tumor-specific, cytotoxic CD4<sup>+</sup> T cells from tyrosinase-related protein 1 transgenic mice could overcome secondary resistance to recurring melanoma when anti-programmed cell death 1 ligand (PD-L1) checkpoint blockade was combined with either anti-lymphocyte-activated gene 3 (LAG-3) Abs or depletion of tumor-specific regulatory T (T<sub>reg</sub>) cells.