The application relates to a compound being 3-(4-amino-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione or a pharmaceutically acceptable salt thereof for use in a method of treating a myelodysplastic syndrome, wherein the method further comprises administering to a patient having a myelodysplastic syndrom 5-azacytidine, and wherein the myelodysplastic syndrome has a score of 1.0 or lower in international prognostic scoring system (IPSS).