METTL3 and head and neck squamous cell carcinoma: The completed Phase 1 trial (NCT05584111) established its safety and pharmacologic activity, while an ongoing Phase 1b/2 trial (NCT06975293) is evaluating STC-15 in combination with the PD-1 antibody toripalimab across advanced cancers—including non-small-cell lung carcinoma, melanoma, endometrial carcinoma, and head and neck squamous cell carcinoma—to define optimal dosing, safety, and T cell-modulating efficacy of METTL3 blockade.