Survival Outcomes with Guideline-Concordant Pediatric-Inspired Regimens in Adolescent/Young Adult Acute Lymphoblastic Leukemia: Retrospective Real-World Analysis

BACKGROUND: Pediatric-inspired regimens (PIR) yield excellent outcomes for acute lymphoblastic leukemia (ALL). Despite national guidelines recommending PIR for adolescents and young adults (AYAs; aged 15-39 years), the use of guideline-concordant PIR in AYAs is inconsistent across treatment settings. METHODS: This retrospective observational study compared overall survival (OS) and stem cell transplant (SCT) use among AYAs treated with PIR versus non-PIR. Using a deidentified, geographically representative USA health claims database, we analyzed a cohort of AYAs with newly diagnosed ALL between 1 July 2007 and 30 September 2020. RESULTS: Among 599 patients who met the inclusion criteria, 187 (31%) received PIR, 303 (51%) received non-PIR, and for 109 (18%), treatment was undetermined. PIR and non-PIR groups were propensity score matched (n = 187 each). Using Kaplan-Meier methodology, OS was significantly higher for those treated with PIR versus non-PIR (log-rank P = 0.0001; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.18-0.55). For PIR and non-PIR, 1-, 3-, and 5-year survival estimates (95% CI) were 98.1% (95.3-99.3%) versus 88.3% (83.5-91.7%); 88.5% (82.6-92.5%) versus 69.1% (62.1-75.1%); and 87.3% (81.0-91.6%) versus 63.3% (55.2-70.3%). Sensitivity and subgroup analyses were consistent with primary results. By Kaplan-Meier methodology, SCT use was significantly lower among AYAs treated with PIR than non-PIR (log-rank P = 0.0004; HR, 0.46; 95% CI 0.30-0.71); use by 2 years was 16.5% (12.2-22.2%) and 33.4% (27.6-40.0%), respectively. CONCLUSIONS: These results support the use of guideline-concordant PIR for AYA ALL.