ALBERT

Description: Background: We have previously shown that CMR predicts better outcomes in Ph+ ALL. The lack of achievement of CMR and particularly major molecular response (MMR) at 3 months may confer poor outcomes. We sought to investigate the outcomes of pts who did not achieve CMR at 3 months as best response in terms of progression free survival (PFS) and overall survival (OS), and the role of allogeneic stem cell transplant (ASCT) in this population. Methods: We reviewed 204 pts with newly diagnosed Ph+ ALL treated at our institution between January 2001 and June 2019 with the combination of Hyper-CVAD plus tyrosine kinase inhibitors (TKI); dasatinib (n=88, 43%), ponatinib (n=72, 35%) and imatinib (n= 44, 22%). PFS was defined from the start of therapy to relapse or death. OS was defined from diagnosis to death or last follow-up. Backward multivariate Cox regression was used to identify prognostic factors for PFS and OS after variable selection at a p-value cutoff of 0.200. Time to ASCT was handled as a time-dependent variable. Survival curves were estimated by Kaplan-Meier method. Landmark analysis at the median time to ASCT was analyzed to evaluate the impact of ASCT. Results: We identified 94 pts (46%) who did not achieve 3-month CMR. Of pts treated with imatinib, 29 (66%) did not achieve 3-month CMR and 16 pts (36%) achieved 3-month MMR. Of pts treated with dasatinib, 42 (48%) did not achieve 3-month CMR and 29 pts (33%) achieved 3-month MMR. Of pts treated with ponatinib, 23 (32%) did not achieve 3-month CMR and 17 pts (24%) achieved 3-month MMR. Patient characteristics are summarized in table 1. Median age was 54 years (range: 21-80). The TKI administered was dasatinib, imatinib and ponatinib in 42 (45%), 29 (31%) and 23 (24%) pts, respectively. Overall, ASCT was performed in 28 pts (30%); 21 out of 62 pts (34%) with 3-month MMR, and 7 out of 32 pts (22%) who did not achieve MMR, within a median time of 5 months (range, 2.3-12.3). After a median follow-up of 97 months, median PFS was 21 months and median OS was 46 months. There was no difference in survival by TKI choice. The 5-year PFS and OS rates were 52% and 23% (p=0.001) (Figure 1A), and 58% and 26% (p=0.001) (Figure 1B) for pts with and without 3-month MMR, respectively. In multivariate analysis (table 2), 3-month MMR predicted longer PFS (p