The monoclonal antibody rituximab (Rituxan®), when added to standard chemotherapy as a first-line treatment for follicular lymphoma, significantly delayed the progression of the disease and produced higher response rates, according to findings reported at the American Society of Clinical Oncology (ASCO) annual meeting last week by Dr. Kevin Imrie of the Toronto-Sunnybrook Regional Cancer Center in Canada.
Early results of the trial appeared in Blood in February, 2005 but the more extensive analysis Dr. Imrie reported provides "the first hard evidence that rituximab's demonstrated efficacy with recurrent disease" in follicular and other types of lymphoma extends to first-line treatment.
Previously untreated patients with advanced follicular lymphoma were randomly assigned: 162 patients received rituximab plus a standard first-line chemotherapy regimen of cyclophosphamide, vincristine, and prednisone (CVP); another 159 patients received CVP alone. After four cycles, only those patients who had responded remained in the study and received the final four cycles of whichever regimen they had begun.
Significant differences were seen for nearly all measures in favor of the rituximab-plus-CVP arm. About 81 percent of patients responded to rituximab therapy compared with 57 percent of patients in the CVP-only group. The rituximab patients had a longer median time before their cancer stopped responding to treatment (27 months vs. 7 months) and a longer median time during which their cancer continued to respond to treatment (35 months vs. 14 months). Side effects incidence was similar for both groups.