Rituximab Maintenance in Previously Untreated Follicular Lymphoma: 9-Year Follow-up
As reported in the Journal of Clinical Oncology by Bachy et al, 9-year follow-up of the phase III PRIMA trial indicated a maintained progression-free survival benefit of maintenance rituximab vs observation following first-line induction therapy for follicular lymphoma. As in the prior reports from the trial at 3 and 6 years, a progression-free survival benefit was not accompanied by an overall survival benefit.
Study Details
In the trial, patients with previously untreated high–tumor burden follicular lymphoma received induction with immunochemotherapy regimens consisting of rituximab plus—according to study center preference—CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone; six cycles), CVP (cyclophosphamide, vincristine, and prednisone; eight cycles), or FCM (fludarabine, cyclophosphamide, and mitoxantrone; six cycles). A total of 1,018 patients responding to induction were randomly assigned to rituximab maintenance (375 mg/m2 every 8 weeks, n = 505) or observation (n = 513) until disease progression or for up to 2 years.
Progression-Free and Overall Survival
Median duration of follow-up was 9.0 years. Median progression-free survival was 10.5 years in the rituximab maintenance group vs 4.1 years in the observation group (hazard ratio = 0.61, P < .001). Estimated progression-free survival at 10 years was 51.1% vs 35.0%. Progression-free survival benefit was consistent among subgroups according to age, sex, Follicular Lymphoma International Prognostic Index score, induction chemotherapy, and response to induction.
Median time to next antilymphoma treatment was not reached vs 6.1 years (HR = 0.66, P < .001). At data cutoff, 42.0% vs 55.4% of patients had started a new antilymphoma treatment or died before receiving subsequent treatment. Median time to next chemotherapy treatment was not reached vs 9.3 years (HR = 0.71, P < .001). At data cutoff, 37.2% vs 47.6% of patients had started a new chemotherapy treatment or died before receiving subsequent treatment.
Median overall survival was not reached in either group, with estimated 10-year survival rates being 80.1% vs 79.9% (HR = 1.04, P = .7948).
The investigators concluded, “Rituximab maintenance after induction immunochemotherapy provides a significant long-term [progression-free survival] but not [overall survival] benefit over observation.”
Emmanuel Bachy, MD, PhD, of the Hematology Department, Lyon-Sud Hospital, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The trial was supported by F. Hoffmann-La Roche and Biogen Idec. For full disclosures of the study authors, visit jco.ascopubs.org.
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