by Dr. C.H. Weaver M.D. Medically Reviewed 1/2019
Among patients with low-tumor-burden follicular lymphoma who have received initial treatment with Rituxan® (rituximab), waiting until disease progression to take additional Rituxan is as effective as ongoing, maintenance Rituxan. These results were presented at the 53rd Annual meeting of the American Society of Hematology.
Follicular lymphoma is an indolent (slow-growing) type of non-Hodgkin’s lymphoma. It involves a type of white blood cell known as a B cell. Low-tumor-burden follicular lymphoma refers to lymphoma with a small tumor size, limited lymph node involvement, and limited or no symptoms.
Rituxan is a targeted therapy that binds to a marker known as CD20 on the surface of B-cells. This binding prompts the immune system to destroy the cell, and may also have direct anticancer effects on the cell.
Early treatment with Rituxan may benefit some patients with low-tumor-burden follicular lymphoma. After initial treatment with Rituxan, however, it’s uncertain whether Rituxan should be continued indefinitely (Rituxan maintenance), or whether additional treatment can be deferred until the lymphoma gets worse (Rituxan as-needed).
To compare these two different approaches to Rituxan treatment, researchers conducted a Phase III clinical trial known as RESORT. The study enrolled 384 people with previously untreated, low-tumor-burden follicular lymphoma. All of the study participants received Rituxan for four weeks. Patients were then assigned to ongoing maintenance therapy with Rituxan (a single dose of Rituxan every three months) or to an as-needed treatment group (four weekly doses of Rituxan when the lymphoma shows signs of worsening).
- Patients in the as-needed group received many fewer doses of Rituxan than patients in the maintenance therapy group (4.5 doses on average, versus 15.8 doses).
- Time to treatment failure (disease progression or nonresponse, or need for other therapy) was similar in the two study groups and better than has been reported previously among untreated (“watch-and-wait”) patients. Time to treatment failure was 3.6 years in the as-needed group and 3.9 years in the maintenance therapy group. The difference between the two study groups was not statistically significant, suggesting that it could have occurred by chance alone.
- A secondary outcome of interest was time to chemotherapy. After three years of follow-up, 86 percent of patients in the as-needed group had avoided the need for chemotherapy, compared with 95 percent of patients in the maintenance therapy group. This difference favored the maintenance therapy group and was statistically significant (unlikely to be due to chance), but also required many additional Rituxan doses.
These results suggest both approaches to Rituxan are effective for low-tumor-burden follicular lymphoma. The as-needed approach, however, has the advantage of requiring many fewer doses of Rituxan.
Reference: Kahl BS, Hong F, Williams ME et al. Results of Eastern Cooperative Oncology Group Protocol E4402 (RESORT): A randomized Phase III study comparing two different rituximab dosing strategies for low tumor burden follicular lymphoma. Presented at the 53rd Annual Meeting of the American Society of Hematology. December 10-13, 2011. Abstract LBA-6.