Another phase I study (NCT03329950) evaluated the immunological benefits of the CD40 agonist CDX-1140 against advanced solid tumours, including HNSCC, either alone or in combination with pembrolizumab, chemotherapy or recombinant fms type 3 tyrosine kinase ligand (Flt-3) CDX-301. This evidence concerns the gene FLT3 and head and neck squamous cell carcinoma.