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e18500 Background: Tyrosine kinase inhibitors (TKI) have revolutionized the treatment of acute lymphoblastic leukemia (ALL) with t(9;22) (Ph+). A single-center, single-arm, phase II study published in 2017 reported excellent outcomes in adult patients (pts) treated with ponatinib + HyperCVAD alternating with high-dose methotrexate and cytarabine (HyperCVAD). Complete remission (CR) rate was 100% with 78% of pts achieving complete molecular response (CMR). 2-year (yr) event free survival (EFS) was 81% and overall survival (OS) was 80% with 9/37 pts undergoing allogeneic stem cell transplantation (SCT). This treatment's success changed standard of care for patients with Ph+ ALL; however validation of these findings is needed. Methods: We performed a real-world, retrospective analysis of adult patients with previously untreated Ph+ ALL treated with at least 1 cycle of HyperCVAD + ponatinib or an alternate TKI, at our institution between 2016 and 2023. The primary endpoint was 2-yr EFS. Kaplan-Meier method was used to estimate all time-to-event endpoints and proportions were estimated along with 95% confidence intervals. Results: 19 patients with a median age of 46 yr were analyzed. 18 pts were newly diagnosed; 1 pt had relapsed Ph+ ALL. Median follow up was 29.4 months (m). Baseline characteristics are in the table. All evaluable patients achieved a response (18/18). 1 pt died from septic shock within 4 weeks of treatment start (5.3%). All evaluable pts achieved CMR, defined as undetectable BCR/ABL1 transcript (17/17; 1 missing). Median time to CMR was 3.83 m 1.67, 9.30. Of the 9 pts who underwent SCT, 5 (55.6%) received ponatinib and 4 (44.4%) received an alternate TKI (p=0.350). SCT was planned in 5 pts, but performed for molecular relapse (MR) in 4 pts. No pts had clinical relapse, but incidence of MR was 40.1%. 2-yr cEFS (defined as clinical relapse or death) was 89.2% 63.1%, 97.2%. Median cEFS was greater than 32.6 m 32.6, ∞, but when defined as death or any relapse, it decreased to 18.40 m 7.27, ∞. 2-yr OS was 89.2% 63.1%, 97.2%. Conclusions: While 2-yr OS and EFS are similar in our cohort to published data, a surprisingly large number of patients experienced molecular relapse, which was not reported in the original trial. While our sample size was small, there was no significant difference in CR or transplant status for patients treated with Hyper CVAD + ponatinib versus alternate TKI. Table: see text
Rakiewicz et al. (Sat,) studied this question.