We evaluated the role of rituximab (R) both in remission induction and maintenance treatment of relapsed/resistant follicular lymphoma (FL). A total of 465 patients were randomized to induction with 6 cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) (every 3 weeks) or R-CHOP (R: 375 mg/m 2 intravenously, day 1). Those in complete remission (CR) or partial remission (PR) were randomized to maintenance with R (375 mg/m 2 intravenously once every 3 months for a maximum of 2 years) or observation. R-CHOP induction yielded an increased overall response rate (CHOP, 72.3%; R-CHOP, 85.1%; P < .001) and CR rate (CHOP, 15.6%; R-CHOP, 29.5%; P < .001). Median progressionfree survival (PFS) from first randomization was 20.2 months after CHOP versus 33.1 months after R-CHOP (hazard ratio [HR], 0.65; P < .001). Rituximab maintenance yielded a median PFS from second randomization of 51.5 months versus 14.9 months with observation (HR, 0.40; P < .001). Improved PFS was found both after induction with CHOP (HR, 0.30; P < .001) and R-CHOP (HR, 0.54; P ؍ .004). R maintenance also improved overall survival from second randomization: 85% at 3 years versus 77% with observation (HR, 0.52; P ؍ .011). This is the first trial showing that in relapsed/ resistant FL rituximab maintenance considerably improves PFS not only after CHOP but also after R-CHOP induction.
IntroductionFor patients with follicular lymphoma (FL) chemotherapy alone has not resulted in improved overall survival (OS) over the past 30 years. [1][2][3][4] Although in most patients complete remissions (CRs) or partial remissions (PRs) can be obtained with either single agents or combination chemotherapy, the clinical course is characterized by a high relapse rate. After relapse, both the response rate and relapse-free survival after subsequent salvage treatment regimens steadily decrease, resulting in a median survival of only 4 to 5 years after first relapse. [5][6][7][8] Therefore, new treatment modalities resulting in increased progression-free survival (PFS) and OS are urgently required. Optimal treatment of patients relapsed after 1 or 2 chemotherapy regimens is largely unknown.Rituximab (R) is a chimeric murine/human anti-CD20 monoclonal antibody capable of killing CD20 ϩ lymphoma cells. Effector mechanisms include complement-mediated cytotoxicity, antibodydependent cellular cytotoxicity, and possibly direct induction of apoptosis. 9,10 In the nonrandomized pivotal study in 166 relapsed low-grade lymphoma patients, monotherapy with rituximab resulted in a response rate of 48%, with a 6% complete remission (CR) rate and a median time to progression in responding patients of 13 months. 11 Toxicity was generally mild to moderate (grade 1 or 2) and occurred primarily with the first infusion. 11 In a subsequent small phase 2 study, the combination of R with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) was shown to be safe and effective. 12 Treatment results in FL might not only be improved by more effective induction...