Abstract: The present invention relates to a pharmaceutical product comprising a combination of methotrexate and novobiocin, or any pharmaceutically acceptable salts of said compounds, and a pharmaceutical composition comprising (i) a therapeutic amount of methotrexate or any pharmaceutically acceptable salts thereof, and one or more pharmaceutically acceptable excipient, carrier or diluent, (ii) a non-therapeutic amount of novobiocin or any pharmaceutically acceptable salts thereof, and one or more pharmaceutically acceptable excipient, carrier or diluent. The invention further relates to a use of the pharmaceutical product and composition in therapy, such as prevention, progression prophylaxis and/or treatment of autoimmune diseases.