Radioimmunotherapy effective first-line treatment for follicular lymphoma

The anti-CD20 antibody tositumomab labeled with iodine-131 can induce prolonged remissions in patients with follicular lymphoma when used as first-line therapy, according to phase II trial results reported in the New England Journal of Medicine for February 3.

“This appears to be as good as any state-of-the-art chemotherapy regimen that’s out there for follicular lymphoma,” Dr. Mark S. Kaminski told Reuters Health. And with minimal side effects, “it’s very patient-friendly,” he added.Dr. Kaminski, an oncologist at the University of Michigan Medical Center in Ann Arbor, and colleagues enrolled 76 previously untreated patients with stage III or IV follicular lymphoma. Treatment involved two infusions of 131-I-tositumomab administered approximately 1 week apart.Seventy-two patients (95%) exhibited a response, with complete responses observed in 57 (75%). Five-year progression-free survival was 59% overall, and 77% among those with complete response. Five-year overall survival was 89%.The annualized rate of relapse declined progressively over time, the authors note, from 15% during the first year to 4.4% per year after 3 years.Hematologic toxicity was moderate and reversible, with no patients requiring transfusions or hematopoietic growth factors. Furthermore, “there was no hair loss and only minimal nausea,” Dr. Kaminsky added.These results “compare favorably with the best published results of studies of any type of initial therapy, including monoclonal anti-CD20 antibody (rituximab) alone, intensive chemotherapy, or chemotherapy combined with rituximab,” the authors note.”This article is not advocating Bexxar as front-line treatment, but it opens the door for further clinical trials so we can best determine which of the many different approaches to use for this kind of lymphoma and in what sequence,” Dr. Kaminski stressed. But perhaps the “bigger message,” he added, is that “this is so effective up front, don’t wait until the last minute to give this to your patients. Move it further up in the treatment plan.”In a related editorial, Dr. Joseph M. Connors, from the University of British Columbia in Vancouver, Canada, cautions that “evidence of the superiority of the new treatment can emerge only from carefully designed prospective, randomized trials.” Also, an economic analysis is needed “to answer the important question of cost for this potentially very expensive new treatment.”(Source: N Engl J Med 2005;352:441-449,496-498: Reuters Health: February 2005.)