P062 | OUTCOMES OF YOUNGER ADULT PATIENTS WITH PHILADELPHIA-NEGATIVE ACUTE LYMPHOBLASTIC LEUKEMIA (PH- ALL) OR LYMPHOBLASTIC LYMPHOMA (LL), TREATED IN THE REAL-LIFE WITH A PEDIATRIC-LIKE REGIMEN BASED ON GIMEMA LAL1308 PROTOCOL: A RETROSPECTIVE CAMPU

While the use of pediatric-inspired regimens (PIRs) has significantly improved survival outcomes in patients (pts) with Ph- ALL up to the age of 55-65 years, there is no clear evidence that adolescents and young adults (AYA) may have additional benefits when undergoing unmodified pediatric protocols compared with PIRs. We retrospectively analyzed outcomes of 35 younger pts (median age 21 years, range 18-38) affected with Ph- ALL (27) or LL (8), observed across Italian centers partecipating to the Campus ALL network between 2014 and 2023, and receiving an intensive treatment inspired by the GIMEMA LAL1308 pediatric protocol (Testi et al, Am J Hematol 2021) in a real-life setting. B- and T-cell immunophenotypes were observed in 23 (65.7%) and 12 (34.3%) ALL/LL cases, respectively. According to prognostic risk stratification, 15 (55.6%), 5 (18.5%) and 7 (25.9%) ALL pts were classified as standard, high or very high risk, respectively. CNS localization at onset was detected in only 2 (5.7%) cases. Following induction course Ia, a morphologic CR was achieved in 23/27 (85.2%) ALL cases, while a morphologic or metabolic CR was eventually documented in 30/35 (85.7%) globally considered ALL/LL pts after phase Ib. MRD negativity was reached in 18/24 (75%) evaluable ALL pts at the prognostic timepoint at the end of Ib induction cycle (TP2). Eight of 24 (33.3%) ALL pts subsequently experienced either a morphologic or a MRD relapse, with 7 pts receiving blinatumonab, with or without previous salvage chemotherapy. Consolidation/maintenance approaches followed risk-adapted indications without dose-limiting complications, with 17 (48.6%) ALL/LL pts collectively receiving an alloHSCT, due to either adverse prognostic factors, resistance to induction courses, morphologic relapse or MRD positivity at TP2 or subsequent determinations. At a median follow-up of 43 months (range 20-75), the median OS and DFS for the entire cohort were not reached, with 5-year OS and DFS of 75% and 62%, respectively. No significant differences in outcomes were recorded according to the ALL/LL diagnosis, B/T phenotype, risk at diagnosis or, surprisingly, MRD status at TP2, probably due to the small sample size or to optimal risk-adapted and MRD-driven intensification strategies. Unmodified pediatric regimens may be safely administered to AYA ALL pts in the real-life, with results that compare favorably to those of the LAL1308 trial or other intensive PIRs not incorporating upfront immunotherapy.