In addition to significant improvements in 5-year OS and PFS with maintenance rituximab, there was a trend toward an association between maintenance and reduced transformation risk.
Survival outcomes of patients with follicular lymphoma may be improved with the use of upfront rituximab maintenance treatment, according to the results of a population-based study.
In the study, patients who received first-line treatment with rituximab in combination with chemotherapy followed by maintenance rituximab had improved progression-free survival (PFS) and overall survival (OS).
“The role of maintenance rituximab as part of the first-line standard of care strategy in treatment requiring follicular lymphoma is still debated,” Charlotte Madsen, of the department of hematology at Aarhus University Hospital, Denmark, and colleagues, wrote in Blood Advances. “The present study adds to the existing data by showing that, in two independent cohorts of follicular lymphoma patients, the use of maintenance rituximab leads to an improvement of not only progression-free survival, but also overall survival.”
According to the study, although follicular lymphoma can have a chronic clinical course, it is still considered an incurable disease. Some patients who recur will experience histological transformation of their disease. The introduction of maintenance rituximab had improved PFS for patients with follicular lymphoma, but its effect on OS and histological transformation is unknown.
Madsen and colleagues used two independent population-based cohorts to look at the effect of up-front rituximab maintenance. The training cohort included 733 Danish patients who had completed first-line induction with rituximab-chemotherapy, who were alive and eligible for maintenance rituximab, and who had no evidence of histological transformation. Of the 733 patients, 364 were consolidated for maintenance therapy.
The patients who were consolidated for maintenance rituximab more often had advanced clinical stage (90% vs 78%), high FLIPI (Follicular Lymphoma International Prognostic Index) score (64% vs 55%), and bone marrow infiltration (49% vs 40%).
Patients who underwent maintenance treatment had significant improvements in 5-year OS (89% vs 81%; P = .001) and PFS (72% vs 60%; P < .001). In addition, there was a trend toward an association between maintenance and a reduction of transformation risk in this cohort.
The researchers validated the results in an independent cohort of 190 Finnish patients and were able to confirm the positive effect of maintenance rituximab on 5-year OS (89% with maintenance rituximab vs 81% without it; P = .046) and PFS (70% vs 57%; P = .005). However, no reduced risk for transformation was found.
“The fact that a number of prospective and retrospective studies seem to report an advantage in progression-free survival rather than overall survival for follicular lymphoma patients treated with maintenance rituximab after front-line induction may reflect the prolonged overall survival of follicular lymphoma patients in the rituximab era,” the researchers wrote. “In the light of a lower number of events, there will be an inevitable need [for] large study populations and extensive length of follow-up in order to demonstrate significant overall survival differences. This need may justify, despite their inherent limitations, a role for large population-based retrospective analyses, such as the present one.”