Rituximab maintenance significantly reduces early follicular lymphoma progressions in patients treated with frontline R-CHOP.

Abstract

Twenty percent of patients with high‐tumor‐burden (HTB) follicular lymphoma (FL) develop progression/relapse of disease (POD) within 24 months of frontline immunochemotherapy. Unfortunately, about 50% of these patients die within 5 years since POD event. Rituximab maintenance was proven to reduce relapse rate in responding FL, but its role on preventing POD was not defined. We analyzed 1360 HTB‐FL patients from the Czech Lymphoma Study Group registry treated with frontline rituximab‐containing regimen. Of those, 950 cases received rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP) and achieved complete or partial remission: 712 patients received rituximab maintenance (MAINT) and 238 were a historical observational cohort (OBS). We have proposed a modified POD24 (mPOD24) endpoint for the chemosensitive patients calculated from the end‐of‐induction (EOI). Survival rates since EOI were as follows: 5‐year overall survival (OS) 86.2% versus 94.5% in the OBS and MAINT groups, respectively (P < .001) and 5‐year progression‐free survival 58.5% (OBS) and 75.4% (MAINT) (P < .001). The Cox proportional hazards model showed a decrease in mPOD24 incidence in the MAINT group with the overall hazard rate reduced by 56% (hazard ratio = 0.44; P < .001). The cumulative incidence of mPOD24 was reduced from 24.1% in OBS to 10.1% in MAINT (P < .001). Comparison of non‐mPOD24 cases showed OS similar to that in the general population. Rituximab maintenance given after R‐CHOP resulted in a 2.4‐fold reduction in mPOD24 incidence. Once the non‐POD24 status is achieved, FL does not shorten the patients’ life expectancy.