For R/R patients, FLT3-ITD status and allelic burden will be confirmed before treatment. Both groups of patients will receive sorafenib 400 mg twice daily continuously and OM 1.5 mg/m2 daily for 7 days every 28 days until progression or allogeneic hematopoietic stem cell transplantation (HSCT). Thereafter, patients will be followed up and information about disease status and survival will be collected. BM examination will be performed on day 28 to document morphological response and FLT3-ITD allelic burden.