For patients randomly assigned to R-chemotherapy, physicians could choose among three standard regimens: rituximab plus bendamustine (R-B), rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), or rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP).
There was no statistical difference between treatment approaches in CR/CRu at 120 weeks, which was 48% in the R2 arm and 53% in the R-chemotherapy arm (P = 0.13). Best CR/CRu also was not statistically different between arms (59% and 67%, respectively), as was best overall response rate (84% and 89%). The 3-year duration of response was 77% in the R2 arm and 74% for R-chemotherapy.
With 37.9 months median follow-up, progression-free survival was “nearly identical” between the two groups, Dr. Fowler said, at 77% for R2 and 78% for R-chemotherapy (P = 0.48). The 3-year overall survival was 94% in both the R2 and R-chemotherapy arms, though survival data are still immature, Dr. Fowler noted.
Grade 3/4 neutropenia was more common in the R-chemotherapy arm, resulting in higher rates of febrile neutropenia, according to Dr. Fowler, who also noted that rash and cutaneous reactions were more common with R2. About 70% of patients in each arm were able to tolerate treatment, and reasons for discontinuation were “fairly similar” between arms, Dr. Fowler added.