Ph Negative B-Acute Lymphoblastic Leukemia (All) in Adolescents and Young Adults (Aya): Argentine Real-World Data On Prognostic Factors And Treatment

RIVAS, MARÍA M; DICK, HERNÁN; NAVICKAS, ALICIA; PARRELADA E; PAGANINI, MARIA; MOIRANO, MARÍA; FERNANDEZ, ISOLDA; SACKMANN, FEDERICO; GIMENEZ CONCA, ALBERTO; AGAMENNONI, LUCIA; REY, IRENE; FERRARI, LUCIANA; FISCHMAN, LAURA; CAZAP, NICOLÁS; NEGRI ARANGUREN, FLORENCIA; BRULC, ERIKA; BELLI, CAROLINA

Madrid (Virtual)

Congreso; 25th Congress of the European Hematology Association; 2020

European Hematology Association

Background: Historically AYA patients (pts) with ALL had a worse prognosis compared with children. These results may depend on the biology of the disease; however, therapeutic approaches (pediatric vs adult protocols) and the experience of treating groups may also have an impact on their outcomes. Knowing the risk and response predictors are essential to adapt those strategies.Aims: The primary end point was to evaluate the response and survival achieved according to the different treatments used.The secondary end point was to assess predictors of response in terms of overall survival (OS) and event-free survival (EFS).Methods: We performed a retrospective multicenter analysis of AYA pts diagnosed between Jul-12 to May-19, from 11 Argentine institutions. Prognostic predictors were analyzed upon: prednisone response (PR) at day (d) 8, measurable residual disease (MRD) at d15, 33, 78 and risk stratification. Events were defined as relapse, refractoriness or death. Fisher's exact test, Kaplan-Meier / log rank test and Cox regression were used for statistical analysis.Results: One hundred and thirty-three pts with a median (Md) age of 22 years (15-49) have been recorded. At diagnosis, 74% had immunophenotype B, 60% were high risk (HR), 26% presented CNS involvement and 18.5% with adverse cytogenetic/molecular findings (8% MLL rearrangements, 3% hypodiploid and 7.5% complex karyotypes).The protocols used were: 71% pediatric and 23% adult Argentine type-BFM, 5% Spanish type-BFM and 1% Hyper CVAD. Nineteen percent(15/80) of HR pts performed allogeneic bone marrow transplantation (Allo-HSCT) at 1st remission.Of 133 pts, 120 (90%) achieved complete remission (CR) and 113 (85%) negative MRD, 5 (4%) were refractory, 6 (4.5%) died prior/during induction, 2 (1.5%) were not evaluated yet. The Md to reach a CR and MRD (-) was 33.5 d (12-172) and 35 d (12-242), respectively.With a Md follow-up of 12 months (1-73), 31 pts (23%) relapsed and 47 pts (35%) died. The Md OS and EFS were 58and 38 months, respectively. Pts under a pediatric protocol displayed a better OS (58 vs 15 m, p =0.004, HR 2.4, 95%CI [1.3-4.3]) and EFS (NR vs 9 m, p =0.002, HR 2.3, 95%CI [1.3-4.0]), as compared to those under the adult ones.The OS and EFS were significant better for pts with: response at d8, MRD 0.01% at d78 in terms of OS (d33: NR vs. 9 m, p =0.001, HR 0.2, 95%CI [0.04-0.8]; d78: NR vs. 6 m, p =0.005, HR 0.1, 95%CI [0.03-0.6]) and EFS (d33: NR vs. 7 m, p =0.007, HR 0.3, 95%CI [0.07-0.8]; d78: NR vs. 5 m, p =0.001, 0.1 HR, 95%CI [0.02-0.5]).