A Multicenter Phase II Study of Twice-Weekly Bortezomib plus Rituximab in Patients with Relapsed Follicular Lymphoma: Long-Term Follow-Up

Single-agent bortezomib (B) has shown activity in heavily pretreated patients with relapsed/refractory indolent lymphoma. On the basis of these findings, we performed a phase II study of B combined with rituximab (R) in patients with relapsed follicular lymphoma (FL). Forty-five patients with fairly good prognostic profiles were enrolled from 2007 to 2011 and received a total of 6 cycles of the B+R combination. The endpoints were the overall response rate (ORR), progression-free survival (PFS), duration of remission (DoR), overall survival (OS), and toxicity evaluation. When considering all the enrolled patients the ORR was 64%. At 5 years, the estimated PFS, DoR, and OS were 34, 49, and 70%, respectively. After excluding the 7 R-naïve patients, the ORR was 58%, with a PFS of 19 months. The most common grade >2 toxicities were thrombocytopenia (18%), peripheral neuropathy (13%), and neutropenia (2%). Our study shows the feasibility, long-term efficacy, and excellent tolerability of the B+R combination. We are aware that our study has specific limitations, such as the small sample size consisting of patients with a relatively good prognostic profile. However, because FL patients will be treated with subsequent chemotherapy regimens, a well-tolerated and effective chemotherapy-free therapy could be considered an additional tool for long-term disease control.