Children’s Oncology Group AALL0434: A Phase III Randomized Clinical Trial Testing Nelarabine in Newly Diagnosed T-Cell Acute Lymphoblastic Leukemia
Kimberly P. Dunsmore, Stuart S. Winter, Meenakshi Devidas, Brent L. Wood, Natia Esiashvili, Zhiguo Chen, Nancy Eisenberg, Nikki Briegel, Robert J. Hayashi, Julie M. Gastier‐Foster, Andrew J. Carroll, Nyla A. Heerema, Barbara L. Asselin, Karen R. Rabin, Patrick A. Zweidler‐McKay, Elizabeth A. Raetz, Mignon L. Loh, Kirk R. Schultz, Naomi Winick, William L. Carroll, Stephen P. Hunger
Abstract
PURPOSE Nelarabine is effective in inducing remission in patients with relapsed and refractory T-cell acute lymphoblastic leukemia (T-ALL) but has not been fully evaluated in those with newly diagnosed disease. PATIENTS AND METHODS From 2007 to 2014, Children’s Oncology Group trial AALL0434 (ClinicalTrials.gov identifier: NCT00408005 ) enrolled 1,562 evaluable patients with T-ALL age 1-31 years who received the augmented Berlin-Frankfurt-Muenster (ABFM) regimen with a 2 × 2 pseudo-factorial randomization to receive escalating-dose methotrexate (MTX) without leucovorin rescue plus pegaspargase (C-MTX) or high-dose MTX (HDMTX) with leucovorin rescue. Intermediate- and high-risk patients were also randomly assigned after induction to receive or not receive six 5-day courses of nelarabine that was incorporated into ABFM. Patients who experienced induction failure were nonrandomly assigned to HDMTX plus nelarabine. Patients with overt CNS disease (CNS3; ≥ 5 WBCs/μL with blasts) received HDMTX and were randomly assigned to receive or not receive nelarabine. All patients, except those with low-risk disease, received cranial irradiation. RESULTS The 5-year event-free and overall survival rates were 83.7% ± 1.1% and 89.5% ± 0.9%, respectively. The 5-year disease-free survival (DFS) rates for patients with T-ALL randomly assigned to nelarabine (n = 323) and no nelarabine (n = 336) were 88.2% ± 2.4% and 82.1% ± 2.7%, respectively ( P = .029). Differences between DFS in a four-arm comparison were significant ( P = .01), with no interactions between the MTX and nelarabine randomizations ( P = .41). Patients treated with the best-performing arm, C-MTX plus nelarabine, had a 5-year DFS of 91% (n = 147). Patients who received nelarabine had significantly fewer isolated and combined CNS relapses compared with patients who did not receive nelarabine (1.3% ± 0.63% v 6.9% ± 1.4%, respectively; P = .0001). Toxicities, including neurotoxicity, were acceptable and similar between all four arms. CONCLUSION The addition of nelarabine to ABFM therapy improved DFS for children and young adults with newly diagnosed T-ALL without increased toxicity.