Randomized phase II study of concurrent and sequential combinations of rituximab (R) plus CHOP (R-CHOP) in untreated indolent B-NHL: 7-year follow-up results

Abstract

8616 Background: R-CHOP is regarded as one of the most effective initial treatments for indolent B-cell Non-Hodgkin lymphoma (B-NHL); however, the information on its long term outcome is limited. Methods: Sixty-nine patients (pts) with untreated indolent B-NHL of advanced stages were randomized in the concurrent or sequential combinations of R-CHOP. Pts in the concurrent arm (Arm C) received 6 times of R (375 mg/m2), 2 days prior to each cycle of CHOP, and pts in the sequential arm (Arm S) received weekly 6 times of R (375 mg/m2) following 6 cycles of CHOP. No maintenance therapy was given in both arms. The last pt was enrolled in July, 2000, and the planned observation was completed in May, 2007. Results: A total of 69 pts were randomized but 2 were withdrawn before receiving treatment because of neutropenia or concomitant cancer. Sixty-five pts (94%) had follicular lymphoma, and 31 pts were in low, 27 in intermediate and 11 in high risk group according to the Follicular Lymphoma International Prognostic Index, respectively. We previously reported that overall response rate (ORR) in Arm C was 94%, including a 66% complete response (CR) compared with 97%, including a 68% CR in Arm S, and the time to achieving response was shorter in Arm C than Arm S (p=0.322) (Cancer Sci 2006;97;305). The median progression-free survival (PFS) of the 67 pts was 49 months; 36 months in Arm C (n=34) and 62 months in Arm S (n=33) (p= 0.417). And at 7years the estimated probability of PFS of the 67 pts was 33% (95% CI; 22–44%); 28% in Arm C and 39% in Arm S. Three pts (Arm C, 1; Arm S, 2) died. Six pts (18%) in Arm C and 11 (33%) in Arm S were progression-free at 7 years. Overall survival (OS) of the 67 pts was 96%. During the follow-up periods, clinically significant adverse event was not observed. Conclusions: R-CHOP is a highly effective initial treatment for untreated indolent B-NHL in terms of ORR and OS. However, its long-term PFS is not good enough either in a concurrent or sequential combination, warranting further investigations on post-remission therapy after R-CHOP. No significant financial relationships to disclose.