Follicular Lymphoma Treatment Better With RituximabKey Words
Follicular lymphoma, rituximab (Rituxan®), monoclonal antibody. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary.)
Summary
In patients with newly diagnosed follicular lymphoma, the addition of rituximab, a monoclonal antibody, to the standard chemotherapy regimen CVP dramatically delayed the progression of disease, produced higher response rates that lasted longer, and extended survival compared to treatment with CVP alone.
Source
Journal of Clinical Oncology, July 28, 2008 [Epub ahead of print] (see the journal abstract)
J Clin Oncol. 2008 Jul 28. [Epub ahead of print]
Background
Follicular lymphoma is one of the most common kinds of non-Hodgkin lymphoma. Its progression rate varies widely, though it tends to spread slowly and has few symptoms. Patients with follicular lymphoma usually survive ten years or longer.
Rituximab (Rituxan®) is a monoclonal antibody that has been used to treat various cancers of the blood (leukemia) and the lymphatic (lymphoma) systems. It has been used successfully, both alone and in combination with standard chemotherapy, in patients whose follicular lymphoma has either recurred or proven resistant to other treatment. In addition, long-term data from several clinical trials have shown that the addition of rituximab to first-line chemotherapy improves long-term outcomes.
The trial described here was begun in 2000 to evaluate adding rituximab to a chemotherapy regimen called CVP (cyclophosphamide, vincristine, and prednisone), which is commonly used as a first-line treatment for follicular lymphoma. Preliminary findings from this trial, published in the Feb. 15, 2005, issue of the journal Blood (see the journal abstract) showed that the addition of rituximab to CVP (R-CVP) significantly improved response rates (the percentage of patients whose cancer shrinks or disappears after treatment) and lengthened the time before patients' disease progressed.
However, the preliminary data could not answer the question of whether rituximab improved overall survival, because most patients were still alive at the time of the analysis.
The Study
Previously untreated patients with advanced (stages III to IV) follicular lymphoma were randomly assigned to one of two groups: 162 patients received R-CVP, and 159 received CVP alone. Patients were evaluated after four cycles and if their cancer showed no response, they were removed from the study and provided other treatment. Those who remained in the study received the final four cycles of whichever regimen they had begun.
The study's lead author is Robert Marcus, M.B., from the Department of Hematology at Kings College Hospital, London, United Kingdom.
Results
Significant differences were seen in nearly all measures in favor of the R-CVP arm, where 81 percent of patients responded to therapy compared to 57 percent of patients in the CVP-only group.
Patients receiving R-CVP also did better in other important ways: the median time before their cancer stopped responding to treatment (27 months in the R-CVP group vs. 7 months in the CVP-only group) and the median time their cancer continued to respond to treatment (35 months vs. 14 months).
The median time before death or the need for a different antilymphoma treatment was 49 months for the R-CVP group compared to 12 months for the CVP group. Patients receiving R-CVP were more likely to be alive four years after treatment than patients receiving CVP (83 percent vs. 77 percent. Side-effects were no more serious in the R-CVP group than in the CVP group.
Limitations
This trial was not designed to test whether giving rituximab as part of first-line therapy helps patients live longer than giving rituximab after the disease progresses, explained Sandra J. Horning, M.D., from California's Stanford University Medical Center in an accompanying editorial. Because the investigators could not directly compare patients receiving rituximab as first-line and second-line therapy (only about one-third of patients in the CVP arm received rituximab at first relapse), "the results from this trial cannot fully address the question of sequence," said Horning.
"That to me would be the important question: if you take everyone who got R-CVP and compared them to people who got CVP, but then at relapse got rituximab, was there a survival benefit of getting rituximab upfront?" asks Wyndham Wilson, M.D., head of the Lymphoma Therapeutics Section of the National Cancer Institute's Center for Cancer Research.
Comments
Despite the fact that the trial cannot answer the question of whether rituximab as first-line or second-line therapy provides better overall survival, "the data suggest that primary treatment with rituximab plus chemotherapy in follicular lymphoma patients who require therapy leads to longer overall survival, particularly in higher risk disease and if the use of subsequent rituximab…is delayed or uncertain," concludes Horning.
"The bottom line is that the use of rituximab upfront with chemotherapy seems to prolong survival," agrees Wilson.
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