Can Less Intensive Chemotherapy and an Autotransplant Cure Adult T-Cell Acute Lymphoblastic Leukemia?

Abstract

T-cell acute lymphoblastic leukemia (T-ALL) is a rare disease usually treated with intensive, high-dose consolidation chemotherapy followed by an allotransplant in a substantial number of patients. The data of the RALL-2009 study on 125 adult T-ALL patients suggest that similar total chemotherapy doses given less intensively over a longer interval without interruptions and with an auto- rather than an allotransplant produce outcomes like current more intensive protocols and an allotransplant: 9-year cumulative incidence of relapse (CIR), leukemia-free survival (LFS), and survival were 24% (95% CI 16–33%), 70% (95% CI 59–79%) and 62% (95% CI 51–72%). In a landmark analysis, subjects achieving a complete remission and receiving an autotransplant had a lower 9-year CIR (9% [95% CI 2–22%] vs. 29% [95% CI 16–43%]; p = 0.0076) and better LFS (91% [95% CI 79–98%] vs. 58% [95% CI 41–74%]; p = 0.0009) and survival (92% [95% CI 77–99%] vs. 60% [95% CI 44–77%]; p = 0.001) compared with subjects not receiving an autotransplant. In a multivariate analysis, white blood cells ≥100 × 10⁹/L at study entry were significantly associated with worse LFS (HR = 2.842 [95% CI 1.131–7.143]; p = 0.0263) and survival (HR = 6.085 [95% CI 1.918–19.3]; p = 0.0022) because of more early deaths (HR = 2.42 [95% CI 1.04–5.67]; p = 0.041). Receiving an autotransplant correlated with a lower CIR (HR = 0.23 [95% CI 0.07–0.73]; p = 0.0136) and better LFS (HR = 0.27 [95% CI 0.08–0.85]; p = 0.0256) and survival (HR = 0.158 [95% CI 0.045–0.550]; p = 0.0037).