Long-Term Morbidity and Mortality Experienced By Chronic Myeloid Leukemia (CML) Patients after Allogeneic Hematopoietic Cell Transplantation (HCT) - a Report from BMTSS-2

Background: Tyrosine kinase inhibitors have become the treatment of choice for CML. However, the high cost and need for life-long treatment contribute to non-adherence and represent a major challenge in their use. Allogeneic HCT is potentially curative, but the very long-term health of the survivors is not known. It is also not clear whether a subgroup of CML patients carries a relatively low risk of long-term morbidity. Methods: We addressed these gaps by studying long-term outcomes in 637 CML patients treated with allogeneic HCT between 1981 and 2010 at City of Hope or Univ MN, and surviving for at least 2y after HCT (median follow-up: 16.7y from HCT); 80% of the cohort was Results: Late Mortality: Overall survival was 72.1% at 20y and 69.9% at 30y from HCT. The 20y cumulative incidence of relapse-related mortality was 3.9% (95% CI, 2.6-5.8%) and of non-relapse-related mortality was 18.2% (95% CI, 19.8-28.1%) (Figure 1). 20y cumulative incidence of mortality by cause of death was as follows: infection (7%), chronic GvHD (6%), subsequent malignant neoplasms (SMNs: 3%). HCT recipients were at 4.4-fold increased risk of death (95% CI, 3.8-5.1, p Conclusions: Conditional on surviving the first 2y after HCT, the overall survival exceeds 70% at 20y and remains stable at 70% at 30y after HCT. Non-relapse related mortality (infections, chronic GvHD, SMNs) is by far the major contributor to the late mortality. Conditional on surviving the first 15y, mortality rates are similar to those observed in the general population. HCT survivors are at a 2.7-fold higher risk of severe/life-threatening morbidity when compared with siblings. The more common morbidities include SMNs, diabetes and coronary artery disease. However, CML patients receiving HCT at Disclosures Snyder: BMS: Membership on an entity's Board of Directors or advisory committees; Ariad: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees. Forman:Mustang Therpapeutics: Other: Construct licensed by City of Hope.