Kaminski MS et al. (2005) 131I-tositumomab therapy as initial treatment for follicular lymphoma. New Engl J Med 352: 441–449

The radioimmunoconjugate 131I-tositumomab has shown promise in the treatment of recurrent follicular lymphoma. For the first time, Kaminski et al. have used the drug in previously untreated patients.

This phase II, open-label study included 76 consecutive patients with low-grade, B-cell lymphoma. All had stable or progressive disease and had received no previous treatment. Patients received a single course of 131I-tositumomab therapy and were followed up for a median period of 5.1 years. A response was observed in 72 (95%) patients; regression of the palpable tumor was in most cases noted within 2 weeks. A complete response—defined as the disappearance of all disease for 1 month or more, or no change in minimal residual radiographic abnormalities for at least 6 months—was recorded in 57 (75%) patients, within a median time of 202 days. Forty of these complete responders remained in remission for 4.3–7.7 years. These response rates were higher than have been achieved using this therapy in previously treated patients. Hematologic toxicity was moderate and reversible, and no patient developed acute myeloid leukemia or myelodysplastic syndrome.

In an accompanying editorial, Joseph Connors points out that the patients included in this study had a good prognostic profile. They had slowly progressive disease, were younger than the average patient and had lower tumor burden. He notes that, while the results were impressive, randomized trials will be needed to determine whether the treatment is superior to current strategies.