How safe and effective is R-CHOP as a first-line treatment for patients with FL in the long-term?

This study compared the safety and effectiveness of R-CHOP (rituximab combined with cyclophosphamide, doxorubicin, vincristine, prednisone) to CHOP-RIT (CHOP followed by iodine-133-tositumomab, Bexxar) as a first-line treatment for follicular lymphoma (FL) patients. This study concluded that immunochemotherapy should remain the standard first-line treatment for high-risk FL patients until other therapies are proven superior.

Follicular lymphoma (FL) is the most common type of non-Hodgkin’s lymphoma (NHL), representing 12% of all NHL cases. The current standard first-line treatment for these patients is immunochemotherapy. This type of treatment combines immunotherapy and chemotherapy to stimulate the immune system to attack and destroy cancer cells. However, data about the side effects and effectiveness of immunochemotherapies are limited.

Iodine-133-tositumomab (Bexxar) is a monoclonal antibody with a radioactive particle attached to it. This type of treatment is called radioimmunotherapy (RIT). It binds to cancer cells and gives them the radioactive particle, leading to cancer cell death. The long-term safety and effectiveness of R-CHOP and CHOP-RIT are still under investigation.

This study involved 531 previously untreated FL patients with stage 2 (3%), 3 (36%), or 4 (61%) disease. 70% of all patients had intermediate or high-risk disease. 264 patients received R-CHOP and 267 patients received CHOP-RIT. 93% of all patients completed treatment. The average follow-up period was 10.3 years.

The 10-year progression-free survival (time from treatment before disease progression) rates were 42% (R-CHOP) and 56% (CHOP-RIT). The 10-year overall survival (time from treatment to death of any cause) rates were 81% (R-CHOP) and 75% (CHOP-RIT). 37% (R-CHOP) and 41% (CHOP-RIT) of patients showed a complete response (complete disappearance of all signs of cancer) to treatment. 99% (R-CHOP) and 98% (CHOP-RIT) of patients showed remission.

A total of 117 patients died. Of these, 57.7% (R-CHOP) and 53.8% (CHOP-RIT) were due to disease or treatment complications. 19.2% (R-CHOP) and 26.1% (CHOP-RIT) of deaths were due to secondary cancers. 16.1% (R-CHOP) and 15.1% (CHOP-RIT) of patients developed secondary cancers. The CHOP-RIT group had a 4.9% rate of MDS (myelodysplatic syndrome) or AML (acute myeloid leukemia) compared to 1.8% (R-CHOP).

This study concluded that immunochemotherapy should remain the standard first-line treatment for patients with high-risk FL until other therapies are proven superior. 

This study was partly funded by GlaxoSmithKline, the manufacturer of Bexxar. As of February 2014, the company stopped making and selling Bexxar, and it is no longer available.

Although the mortality rate due to secondary diseases like MDS or AML was higher in the CHOP-RIT group, there were only 12 MDS or AML-related deaths during follow-up. Also, only 40% of patients had available data for these conditions. Because the actual number of deaths was small, this result should be interpreted with caution.