OS after Allogeneic HSCT for AML Stratified at the Time of Transplant By CIBMTR and IWG Response Criteria

Introduction Disease Status of AML patients at the time of HSCT is an important factor in predicting their survival. We hypothesize that MLFS (as per IWG criteria) identifies a group of patients that have better outcome than PIF (as per CIBMTR criteria). Objectives • To identify group of patients previously categorized as PIF by CIBMTR pretransplant that may have favorable outcome with HSCT. • To assess the outcome of patients with primary refractory disease by IWG criteria with HSCT. Methods We retrospectively analyzed 78 patients with AML who underwent allogeneic HSCT between June 2008 and December 2017 at our institution. We assessed the disease status at time of transplant as per CIBMTR criteria as complete remission (CR) defined as 1000, platelets >100,000 with transfusion independence, and primary induction failure (PIF) defined as not achieved CR or CRi. We also assessed the patients at time of transplant as per IWG criteria as CR (similar to CR as per CIBMTR but does not require normal maturation), morphologic leukemic-free state (MLFS) defined as 5%. We compared the OS at one year for the above groups. The patients received myeloablative conditioning with FBT or reduced intensity conditioning with FB2. Results Per IWG criteria, The OS at 1 year was 62 % in the CR group (n=29), 65% in the MLFS group (n=17) and 22% in the PRD group (n= 32). Our analysis revealed an overall statistically significant difference between CR v PRD, p=0.0009 and MLFS v PRD, p=0.0006. When we used the CIBMTR criteria, both MLFS and PRD were reclassified into the PIF group with OS of 34% (n=49). Conclusion Disease status prior to transplant is a predictor of outcome after allogeneic HSCT. Our analysis shows better survival for patients who achieved MLFS prior to transplant according to IWG criteria as compared to patients who were classified as primary induction failure by CIBMTR criteria. We intend to prospectively use the IWG criteria pre-transplant in our patients to help predict their survival at one year.