Long term efficacy and safety of Fludarabine, Cyclophosphamide and Rituximab regimen followed by 90Y-ibritumomab tiuxetan consolidation for the treatment of relapsed grades 1 and 2 follicular lymphoma

Abstract

Background: In this retrospective study, we investigated the efficacy and safety of radioimmunotherapy with 90Yttrium- ibritumomab tiuxetan (90Y-RIT) in 9 patients with recurrent follicular lymphoma (FL) who were treated in a consolidation setting after having achieved complete (CR) or partial remission (PR) with Fludarabine, Cyclophosphamide and Rituximab (FCR). Methods: The median age was 63years (range 46-77). All patients were relapsed with histologically confirmed CD20-positive (grade 1 or 2) FL, at relapse they received FCR every 28days: F (25mg/m2x 3days), C (1 gr/m2day 1) and R (375mg/m2day 4) for 4cycles. Those who achieved at least a PR with <25% bone marrow involvement were treated with 90Y-RIT 11.1 or 14.8MBq/Kg, at 3months after completing FCR. Patients underwent a further restaging at 12weeks after 90Y-RIT with a total body CT scan, FDG-PET/CT and bilateral bone marrow biopsy. Results: Nine patients completed the treatment: FCR followed by 90Y-RIT (6 patients at 14.8MBq/Kg, 3 patients at 11.1MBq/Kg). After FCR, 7 patients obtained CR and 2 PR; after 90Y-RIT 2 patients in PR converted to CR 12weeks later. With a median follow up of 95months (range 20-114) since FCR and 88months (range 13-104) since 90Y-RIT 3 deaths were not related to lymphoma; all 3 deceased patients obtained CR before 90Y-RIT and died still in CR. The median overall (OS) and progression free survival (PFS) have not been reached, in this analysis both OS or PFS are 67% at 7.5year. The most common grade 3 or 4 adverse events were hematologic. Conclusions: These results confirm the long term efficacy and safety of 4cycles of FCR followed by 90Y-RIT in relapsed grades 1 and 2 FL and suggest that this regimen could be a therapeutic option for this setting of patients, specially at age of 60-75 with no unexpected toxicities. 2015