A method for the prophylaxis and/or treatment of a tumour in a subject is provided. The method comprises the steps of administering a therapeutically effective amount of a composition comprising an anti- tumour agent and a therapeutically effective amount of a composition comprising 5-[2-pyrazinyl]-4-methyl-1,2-3-thione, or an analogue, derivative, metabolite, prodrug, solvate or pharmaceutically acceptable salt thereof to the subject. Examples of anti-tumour agents for use in the method of the invention are platinum-based agents, such as cisplatin, and monoclonal antibodies, such Cetuximab. Also provided are compositions comprising an anti-tumour agent and 5-[2-pyrazinyl]-4-methyl-1,2-3-thione, or an analogue, derivative, metabolite, prodrug, solvate or pharmaceutically acceptable salt thereof.
