R-FND Followed by Radioimmunotherapy for High-Risk Follicular Lymphoma

Abstract

Follicular lymphoma (FL) patients, (pts) with high-risk features using the FL International Prognostic Index (FLIPI) have an expected 5-year survival of only about 50% with conventional therapy. With the incorporation of anti-CD20 monoclonal antibody (mAb) therapy, results are improving (e.g., Buske, Blood 2006; 108: 1504). Starting in 2003, we have treated high-risk (FLIPI ≥3) FL pts with R-FND (rituximab, fludarabine, mitoxantrone, dexamethasone) for 4 cycles, followed by radioimmunotherapy (RIT) with ibritumomab tiuxetan, and subsequent rituximab maintenance. Results for the first 35 pts are: complete (CR) and partial (PR) remission 83% and 14%; 3-year overall (OS) and failure-free survival (FFS) 89% and 74% (median follow-up 24 mo.). RIT converted 5 PR pts to CR. Toxicity was mainly hematologic. Five pts did not receive RIT, one because of neutropenia after R-FND. Following RIT, platelet and neutrophil nadirs were 28 and 0.3, occurring at 4–7 weeks. 16 pts required transfusions, and 27 received growth factors. 13 pts had infections, only 2 of which were grade 3. Recovery occurred by 3 weeks in most, with prolonged cytopenias in 6. There has been 1 case of myelodysplasia. In conclusion, the additional complexity of this RIT intensification strategy is warranted in this high-risk FL population, resulting in OS and FFS outcomes that are better than non-mAb therapies, and at least as good as published chemotherapy-rituximab combination therapy.