Feb. 2, 2005 - A new type of lymphoma treatment that combines cancer-killing antibodies and radiation may have potential as a powerful initial attack against an advanced form of non-Hodgkin's lymphoma, according to a new study.
Researchers found a one-week treatment with Bexxar induced a complete remission of the disease that lasted more than five years in most patients with previously untreated follicular lymphoma.
Although these results are exciting, experts say the treatment does not constitute a "cure" for this type of non-Hodgkin's lymphoma. This was a small study on the effectiveness of Bexxar as a first line of treatment in patients with advanced disease, and more research on this approach is required before it can be approved by the FDA for widespread use.
Follicular lymphoma is the second most common form of non-Hodgkin's lymphoma and accounts for more than 20% of all cases. Follicular lymphoma is cancer of the lymph nodes, which are an important part of the immune system, the body's natural defense system against infection.
Bexxar combines the antibody (tositumomab) with radioactive iodine and is administered through an infusion. The antibody stimulates the body's immune system to fight the cancer.
The drug was approved by the FDA in 2003 for the treatment of follicular, non-Hodgkin's lymphoma in patients who have not responded to initial therapy with the drug Rituxan and who have relapsed following chemotherapy. But this is the first study to use the drug in previously untreated patients.
New First-Line Treatment for Lymphoma?
In the study, researchers tested the drug in 76 patients with advanced follicular lymphoma (stage III and IV) who had not yet been treated for their disease. The patients were given a one-week treatment with Bexxar and were followed for about five years.
The results appear in the Feb. 3 issue of The New England Journal of Medicine.
Researchers found that 95% of the patients responded to the treatment; 75% had a complete disappearance of the signs of their cancer.
After follow-up, the estimated five-year overall survival rate was 89%. Fifty-one percent of patients survived during this period with no evidence that their cancer continued to progress.
The rate at which the cancer returned progressively declined over time: 25%, 13%, and 12% during the first, second, and third years after treatment, respectively.
Of the 57 patients who had a complete remission, 40 remained in remission for four to seven years.
Researchers say the toxicity or hazardous side effects of Bexxar were moderate, and none of the patients treated required transfusions or other serious therapy-related complications.
Researchers say the results of this study support using the drug early in the treatment of follicular lymphoma. However, another study is needed to compare the safety and effectiveness of this approach vs. currently available therapies and in a larger number of patients.
No Lymphoma Cure Yet
In an editorial that accompanies the study, Joseph M. Connors, MD, of the British Columbia Cancer Center Agency, says the high response and remission rates with this treatment after four years of follow-up is encouraging.
"For a treatment accomplished in just a few weeks with modest toxicity, these results are especially impressive," writes Connors. "But how impressive? Sufficient enough to claim that patients are being cured? No, relapses are still occurring in 4 percent to 5 percent of patients per year, even after five years. Sufficient to justify 131-I-tositumomab as a primary treatment for follicular lymphoma? No. Sufficient to justify additional clinical trials? Yes."
Connors points out that the patients in the study were a highly select group of younger-than-average patients with a low-to-moderate disease burden, and the drug still needs more study before it's adopted as a first line of treatment for follicular lymphoma.