A monoclonal anti-CD44 antibody, or antigen-binding fragment thereof, for use in the treatment of a head and neck squamous cell carcinoma (HNSCC) in a mammal, wherein said HNSCC is characterized by the expression of CD44. Said monoclonal antibody may be produced by the hybridoma deposited with the ATCC with the accession number PTA-4621, and may be chimeric or humanized versions thereof.