Role of Allogeneic Stem Cell Transplant in Chronic Lymphocytic Leukemia and its Implications in Current Era

CLL is the most prevalent adult leukemia in the western countries with 18,960 new cases diagnosed in 2016 and estimated mortality of 25% per year [1]. It is an extremely heterogeneous disease with the clinical course varying from patients who never require therapy to a rapidly progressive and fatal malignancy in others. While most patients treated with fludarabine, cyclophosphamide and rituximab achieve 3-years OS of 87%, there is a high risk CLL group that has a dismal prognosis with a 4-years OS of less than 20% when they are treated with chemo immunotherapy [2,3]. High risk CLL is defined by presence of non-response or early relapse (within 12 months) after purine analogues, relapse within 24 months after having achieved a response with purine analogue-based combination therapy or autologous transplantation, and patients with p53 mutation or del(17p) requiring treatment. In 2007 the European Group for Bone Marrow Transplantation (EBMT) recommended that patient with high risk disease should be considered for allogeneic stem cell transplant [4].