by Dr. C.H. Weaver M.D. updated 2/2019
Among patients with follicular lymphoma, the addition of Rituxan® (rituximab) to the CVP (cyclophosphamide, vincristine, and prednisone) chemotherapy regimen improves the response rate and time to disease progression (time before lymphoma worsens), but may not significantly improve survival. These results were first published in the medical journal Blood, and were updated at the 47th annual meeting of the American Society of Hematology.
Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. The main cells in the lymph system are lymphocytes, which exist in two forms: B and T-cells. Each of these cells has a very specific function in fighting infection.
NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows-both are determined by the cells’ appearance under a microscope. Follicular lymphoma is considered a low-grade or indolent lymphoma, which means that it is a slow-growing subset of NHL.
Rituxan is a monoclonal antibody that has been designed to recognize and bind to B-cells, which are the cancerous cells in follicular lymphoma. The binding of Rituxan stimulates the immune system to attack the B-cells; other properties of Rituxan are speculated to be involved in the direct killing or disabling of the B-cell.
Although Rituxan is used extensively in the treatment of NHL, is effective, and associated with few side effects, the effect of Rituxan on survival has remained uncertain.
To evaluate the effects of various outcomes, including survival, an international group of researchers conducted a clinical trial among 321 patients with follicular lymphoma. All patients had experienced a complete or partial reduction in lymphoma after four cycles of the CVP chemotherapy regimen. Patients were randomly assigned to receive further therapy with CVP alone or with Rituxan plus CVP (R-CVP).
Compared to CVP alone, treatment with R-CVP improved several patient outcomes, but did not significantly improve survival:
- 81% of patients treated with R-CVP experienced a complete or partial disappearance of detectable lymphoma, compared to 57% of patients treated with CVP alone.
- Time to progression (time before lymphoma worsened) was 34 months among patients treated with R-CVP, compared to 15 months among patients treated with CVP alone.
- There were 12 lymphoma deaths among patients treated with R-CVP and 25 lymphoma deaths among patients treated with CVP alone.
- Survival after three years was 89% among patients treated with R-CVP and 81% among patients treated with CVP alone.
Both treatment regimens were well tolerated. With this longer follow-up, the researchers concluded that R-CVP continued to provide major benefit compared to CVP alone.
Marcus R, Imrie K, Belch A, et al. CVP chemotherapy plus rituximab compared to CVP as first-line treatment for advanced follicular lymphoma. Blood. 2005;105:1417-1423.
Solal-Celigny P, Imrie K, Belch A, et al. Mabthera (Rituximab) Plus CVP Chemotherapy for First-Line Treatment of Stage III/IV Follicular Non-Hodgkin’s Lymphoma (NHL): Confirmed Efficacy with Longer Follow-Up. Blood. 2005;106:106a, abstract number 350.