Role of Allogeneic HCT as Postremission Therapy for Transplant-Eligible Adult Lymphoblastic Leukemia/Lymphoma After Frontline Hyper-CVAD

Background Hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with cytarabine and methotrexate (hyper-CVAD) is a commonly used regimen in adults with acute lymphoblastic leukemia (ALL)/lymphoblastic lymphoma (LBL). Adult patients fit for pediatric-inspired protocols have an excellent outcome with chemotherapy alone. However, it is unclear whether patients receiving hyper-CVAD should undergo allogeneic hematopoietic cell transplantation (HCT) as postremission therapy. Our aim was to examine the role of HCT at first complete remission (CR1) in adult ALL/LBL after hyper-CVAD. Patients and Methods Adult patients with newly diagnosed ALL/LBL receiving frontline hyper-CVAD from 2008 to 2018 were identified and records retrospectively extracted. Results A total of 85 patients were identified and included for further analysis. The median (range) age was 23 (14-68) years, and 56 (66%) were male. A total of 24 (28%) had adverse cytogenetics, and 48 (56%) had at least one risk factor. All patients received hyper-CVAD as induction; induction failure was seen in 10 (12%). A total of 38 patients continued the hyper-CVAD course, while the remaining 47 received HCT in CR1. Three-year event-free survival (EFS) and overall survival for the entire cohort were 51.4% and 61.6%, respectively. Median follow-up of alive patients was 39.9 (3.8-123.8) months. At multivariable analysis for EFS, induction failure was associated with worse outcome (hazard ratio [HR], 4.8; 95% confidence interval [CI] 1.7-13.7; P = .003), whereas HCT in CR1 improved outcome (HR, 0.42; 95% CI 0.18-0.97; P = .044). Furthermore, HCT in CR1 was the only prognostic factor for overall survival (HR, 0.3; 95% CI 0.11-0.85; P = .023). Conclusion HCT at CR1 resulted in a favorable EFS and overall survival in ALL/LBL patients after hyper-CVAD frontline therapy. Given that hyper-CVAD is a widely used protocol for adult patients, further examination of this observation is warranted.