Comparison of the effectiveness of RB and R-CHOP regimens in first-line therapy in 277 patients with grade 1–2 follicular lymphoma: a retrospective single-center analysis
Authors: Sannikova M. A. , Nikitin E. A. , Chernikov M. V. , Kislova M. I. , Agashirinova A. A. , Arakelyan G. R. , Ptushkin V. V. 
Published: January 2025

Background. Chemoimmunotherapy, including cytotoxic drugs and anti-CD20 monoclonal antibodies have significantly improved outcomes in patients with newly diagnosed follicular lymphoma (FL) compared with chemotherapy. A number of clinical studies have compared the effectiveness of the two most popular treatment regimens, rituximab plus bendamustine (RB) and rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP), with conflicting results.

Aim. To conduct a retrospective analysis of the treatment results of a large cohort of patients with grade 1–2 FL who received RB or R-CHOP regimens in the first line therapy in real-life clinical practice, to analyze the impact of individual prognostic factors, as well as rituximab maintenance therapy on survival, the incidence of secondary malignancies and causes of mortality.

Materials and methods. Data were collected on patients with grade 1–2 FL who were treated at the Botkin Hospital from November 2006 to November 2022. The inclusion criteria for the study were newly diagnosed histologically confirmed FL of grade 1–2, age ≥18 years, RB or R-CHOP therapy as first line. No radiation therapy was allowed. Response assessment was performed according to the 2007 International Working Group criteria.

Results. The inclusion criteria for the study were met by 277 patients; 164 patients received R-CHOP and 113 patients received RB. Overall response rate was comparable between groups (96 % vs 94 % in the RB and R-CHOP groups, respectively, p = 0.3396). The median followup period was 35 (3–117) months in the RB group and 50 (3–200) months in R-CHOP group. The median progression-free survival (PFS) in the R-CHOP group was 86 months, while the median of PFS in the RB group was not reached, the differences did not reach statistical significance (hazard ratio (HR) 0.65; 95 % confidential interval (CI) 0.42–1.004; p = 0.0665). Three-year PFS was 81 and 72 %, and five-year PFS was 66 and 57 % in the RB and R-CHOP groups, respectively. Progression within 24 months of initiation of therapy was more common in R-CHOP group (20 % vs 11 %, p = 0.0466). The median time to next therapy in R-CHOP group was 90 months and was not reached in RB group (HR 0.75; 95 % CI 0.48–1.18; p = 0.2277). Unifactor analysis of individual prognostic factors showed superior PFS in most subgroups receiving RB regimen. R-CHOP regimen showed a trend towards improved PFS only in patients with maximum standardized uptake value (SUVmax) >14 (HR 2.46; 95 % CI 0.52–11.62; p = 0.2211). The use of rituximab maintenance therapy improved PFS in both treatment groups: in R-CHOP group, the differences reached the level of significance (HR 0.22; 95 % CI 0.05–1.01; p<0.0001) , in RB group they did not reach the level of significance (HR 0.41; 95 % CI 0.02–8.67; p = 0.3605). There were no significant differences in overall survival. The 5-year cumulative incidence of secondary malignancies as well as the incidence of grade 5 infections were comparable between groups.

Conclusion. In summary, our study shows that RB regimen generally has comparable long-term efficacy to R-CHOP regimen in first-line therapy in patients with grade 1–2 FL. Unifactor analysis of individual prognostic factors showed better PFS in most subgroups using the RB regimen. The use of rituximab maintenance therapy significantly improved PFS in R-CHOP group compared with RB regimen. Our study with a significant median follow-up did not find differences in the incidence of secondary malignancies or non-lymphoma related mortality.