Long-term Overall Survival Data Positive for Bexxar in Treatment-NaÃ¯ve Follicular Lymphoma
New Orleans, LA – Bexxar (tositumomab and iodine I 131) pairs the targeting ability of a monoclonal antibody and the therapeutic potential of radiation to form a radiolabeled monoclonal antibody regimen able to bind to the target antigen 20 found on normal and cancerous B cells. According to a poster presented by Mark S. Kaminski, MD, University of Michigan, Ann Arbor, at the 51st ASH Annual Meeting, 83% of patients with treatment-naïve follicular lymphoma who received Bexxar experienced overall survival of 10 years. The overall response rate was 97%, and median duration of complete response was 9.1 years. The median amount of time follicular lymphoma remained responsive to Bexxar therapy was 6 years. A benefit of Bexxar treatment is that it is administered in 4 visits over 1 to 2 weeks and doses are tailored to an individual’s drug clearance rate, allowing each patient to receive a predetermined amount of radiation.
The follicular lymphoma study presented at ASH was a single-center, single-arm, phase II trial of previously untreated patients (n = 76) with stage III and IV disease. From 0.5 to 2.9 years following treatment with Bexxar, 7% (n = 5) of patients received hormone-replacement therapy. Second malignancies were diagnosed in 11 patients (14%). This included 4 skin neoplasms, 3 breast cancers, 2 prostate cancers, 1 endometrial cancer, and 1 glioblastoma. There was also 1 case of myelodysplastic syndrome diagnosed approximately 8 years after treatment. Hematologic toxicity was common, with 5% of patients experience grade 4 neutropenia; no cases of grade 4 thrombocytopenia were reported.
Based on these data, Dr Kaminski and colleagues conclude that a single course of treatment with a Bexxar therapeutic regimen can produce durable responses, especially durable complete responses lasting over a decade in patients with untreated follicular lymphoma. ASH Abstract 3759.
Disclosure: Authors received funding and support from GlaxoSmithKline.