Real World Clinical Characteristics, Treatment Patterns and Outcomes of R/R B-Cell ALL Adult Patients in Latin America

Introduction. Acute lymphoblastic leukemia (ALL) frequently affects mainly children and young adults. ALL has seen important progresses in diagnosis techniques and treatment approaches in the last decade. However, in some developing countries, there are inequalities in ALL management, such as heterogeneous access to diagnosis technologies (e.g., cytogenetic and molecular profiling) and access to target therapies treatments. To date, there is scarce data on those impacts in treatment patterns and real-world outcomes of adult relapsed/refractory (R/R) B-cell ALL (R/R ALL) patients in Latin America (LA). Therefore, this study aims to describe treatment patterns, clinical characteristics, and outcomes of R/R ALL adult patients treated in LA. Methods. This was a retrospective multicenter non-interventional study to evaluate treatment patterns, clinical characteristics and outcomes conducted in Argentina, Brazil, and Colombia. The study included patients ≥ 18 years old at diagnosis with confirmed R/R ALL between January 1, 2015, to December 31, 2019 that received at least one line of treatment for R/R ALL. Data collected from medical records was considered for the analysis, which was descriptive in nature, as no hypothesis has been tested. Results: A total of 71 patients diagnosed with R/R ALL were included in the study (23 from Argentina, 27 from Brazil, and 21 from Colombia). Table 1 shows the demographics and clinical characteristics. The median age at diagnosis was 31 years (Q1-Q3: 24.0-46.0), 56.3% were male, and 50% were White/Caucasian patients. At diagnosis, the most common comorbidities were diabetes, hypertension, gastrointestinal disease, and thyroid disease, with 11% each. At diagnosis, most patients presented with poor or intermediate cytogenetic risk prognosis, in 55.1% and 31.6%, respectively. Most of the patients presented with good performance status, 50.9% ECOG 0 and 36.8% ECOG 1. As for treatment patterns, patients received up to six treatment lines (LOT-1 to LOT-6), with a median of 2.0 LOTs (Q1-Q3: 1.5-3.0) within the R/R setting. Fifty-three (74.6%) out of the 71 patients enrolled in the study received two lines of R/R treatment (up to LOT-2), and 27 patients (38%) received 3 lines (up to LOT-3). The median treatment duration of LOTs were 3.4 months (Q1-Q3: 1.14 - 5.7), 1.4 months (Q1-Q3: 0.62 - 2.6) and 0.9 months (Q1-Q3: 0.4 - 2.1) for LOT-1, -2 and -3, respectively. The most frequently used treatment regimens at LOT-1 were the Hyper-CVAD