Randomized phase II study of concurrent and sequential combinations of rituximab plus CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) chemotherapy in untreated indolent B-cell non-Hodgkin lymphoma: 7-year follow-up results

Rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) is one of the most frequently applied initial treatments for indolent B-cell non-Hodgkin lymphoma (B-NHL); however, information on its long-term outcome is limited. Untreated patients in the concurrent arm (Arm C) received six R (375 mg/m(2) ) treatments, 2 days prior to each cycle of CHOP, and patients in the sequential arm (Arm S) received 6 weekly R (375 mg/m(2) ) treatments following six cycles of CHOP. Sixty-nine patients were randomized but two patients were withdrawn before receiving the protocol treatment. Sixty-five patients (94%) had follicular lymphoma, and 37 (55%) were at low risk, 23 (34%) at intermediate risk and seven (10%) at high risk according to the Follicular Lymphoma International Prognostic Index. We previously reported that the overall response rate (ORR) in Arm C and in Arm S was 94% and 97%, respectively. The median progression-free survival (PFS)/7-year PFS rate in Arm C, Arm S and all 67 assessable patients was 2.4 years/23% (95% confidence interval [CI], 9-40%), 3.8 years/41% (95% CI, 23-57%) and 2.8 years/32% (95% CI, 20-45%), respectively. There was no significant difference between the two arms (P = 0.107). The overall survival (OS) of the 67 patients was 95% at 7 years. In conclusion, 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 concurrent or sequential combination, warranting further investigations on post-remission therapy.