A Cancer and Leukemia Group B multi-center study of DA-EPOCH-rituximab in untreated diffuse large B-cell lymphoma with analysis of outcome by molecular subtype.

BACKGROUND: A phase II trial of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) from the National Cancer Institute showed promising activity in untreated diffuse large B-cell lymphoma. The Cancer and Leukemia Group B conducted a study to determine if these results could be reproduced in a multi-institutional setting. DESIGN AND METHODS: The study included 69 patients with untreated diffuse large B-cell lymphoma at least 18 years of age and at least stage II. Radiaton therapy was not permitted on study. Median age was 58 years (range 23-83) and 40% had high-intermediate or high International Prognostic Index risk. Immunohistochemical biomarkers for cell of origin and proliferation were performed.
RESULTS: With a median follow up of 62 months, time to progression and overall survival were 81% and 84%, respectively, and time to progression was 87%, 92% and 54% for low/low-intermediate, high-intermediate and high International Prognostic Index risk groups, respectively, at 5-years and beyond. The time to progression and event-free survival of germinal center B-cell lymphoma were 100% and 94%, respectively, and non-germinal center B-cell GCB diffuse large B-cell lymphoma were 67% and 58%, respectively, at 62 months (germinal center vs. non-germinal center B cell P=0.008). DA-EPOCH-R was tolerated without significant grade 4 non-hematologic toxicities.
CONCLUSIONS: These results provide the first confirmation by a multi-institutional group that DA-EPOCH-R provides high durable remissions in diffuse large B-cell lymphoma and is effective in both germinal center and non-germinal center B-cell subtypes. The trial was registered at ClinicalTrials.Gov (NCT00032019).