Long-Term Follow-Up of the RESORT Study (E4402): A Randomized Phase III Comparison of Two Different Rituximab Dosing Strategies for Low-Tumor Burden Follicular Lymphoma.

JCO In 2003, the Eastern Cooperative Oncology Group initiated a randomized phase III clinical trial (E4402) comparing two different rituximab dosing strategies for patients with previously untreated low-tumor burden follicular lymphoma. Rituximab-responsive patients (n = 299) were randomly assigned to either a retreatment rituximab (RR) strategy or a maintenance rituximab (MR) strategy. Each dosing strategy was continued until treatment failure. The primary end point of the study was time to treatment failure (TTF). In the original report, there was no difference in TTF between the two dosing strategies. Here, we report on the long-term outcomes for secondary end points of time to first cytotoxic therapy, duration of response, and overall survival (OS). At 7 years, 83% of MR patients had not required first chemotherapy compared with 63% of RR patients (hazard ratio, 2.37 [95% CI, 1.5 to 3.76]). At 7 years, 71% of MR remained in their first remission compared with 37% of RR patients. Despite the improved first remission length with MR, there was no difference in OS at 10 years (83% 84%). With mature long-term data, we confirm that prolonged maintenance rituximab does not confer an OS advantage in low-tumor burden follicular lymphoma.