Disclosed is the use of a humanized anti-CD4 antibody capable of activating CD4+CD25+ regulatory T cells for the manufacture of a pharmaceutical composition for treating an autoimmune disease in a subject, wherein the humanized anti-CD4 antibody comprises an H chain V domain, an L chain V domain and an IgG 1 constant domain wherein: (a) the H chain V domain compnses the sequences DCRMY, VISVKSENYGANYAESVRG and SYYRYDVGAWFAY, and the L chain V domain compnses the sequences RASKSVSTSGYSYIY, LASILES and QHSRELPWT and/or (b) the H chain V domain has at least 90% sequence identity with SEQ ID No: 1 and the L chain V domain has at least 90% sequence identity with SEQ IDNo: 2, wherein the composition is to be administered to the subject intravenously in a dose of the humanized anti-CD4 antibody of from 0.2 mg to 5 mg or from 2.5 to 20 µg/kg, and wherein the composition is to be administered weekly, every two weeks, every four weeks, every calendar month or every six weeks. Further disclosed is the use of the antibody as defined above in the manufacture of a pharmaceutical composition for treating an autoimmune disease in a subject wherein the composition is to be administered to the subject intravenously in a dose of the humanized anti-CD4 antibody over a period of 10 days of between 0.2 and 7.5 mg, wherein the subject is to receive a plurality of doses.
