Lenalidomide with or without Erythropoietin and Granulocyte-Colony Stimulating Factor Shows Efficacy in Patients with Low and Intermediate-1 Risk Myelodysplastic Syndrome with or without Del 5q, Refractory or Unlikely to Respond to Erythropoietin. Results of a HOVON89 Phase II Randomized Multicenter Study. (EudraCT 2008-002195-10)