Treatment starts with a phase of pomalidomide therapy with 2 mg per day. Individual dose reduction as outlined in the safety section is allowed. If no response was achieved (no complete remission (CR), partial response (PR), clinical improvement (CI) and no progressive disease according to the IWG-MRT criteria) after 3 months, prednisolone is added in a starting dose of 30 mg per day. In the absence of progressive disease, at least 6 months of treatment with pomalidomide is intended. In patients without disease progression after 6 months and those with response to treatment are intended to receive pomalidomide for at least 12 months. Additional antiproliferative treatment with hydroxyurea for leukocytosis (>20 x 109/l) and/or thrombocytosis (>750 x 109/l) and/or symptomatic splenomegaly in a starting dose of 2g/day with individual dose adjustment is allowed.