COLOGNE, Germany—Adding the anti-CD20 monoclonal antibody rituximab (Rituxan) to chemotherapy (R-chemo) achieved better overall survival rates than chemotherapy alone for patients with advanced indolent or mantle cell lymphoma, according to a recent meta-analysis. The R-chemo patients also exhibited better overall response, complete response, and disease control.
Holger Schulz, MD, of the University of Cologne, and his colleagues conducted a meta-analysis of seven randomized, controlled clinical trials involving 1,943 adult patients. The results allowed them to conclude that "concomitant treatment with rituximab and standard chemotherapy regimens should be considered the standard of care for patients with indolent and mantle cell lymphomas who require therapy and for patients with follicular lymphoma" (J Natl Cancer Inst 99:706-714, 2007).
In the seven trials, published from 1990 to 2005, patients with advanced indolent lymphoma and mantle cell lymphoma were randomized to receive either R-chemo or chemotherapy alone. The study excluded ongoing studies, interim analyses, nonrandomized studies, and studies with 10 or fewer patients per study arm. Also excluded were studies involving patients with HIV or primary CNS lymphoma.
Among the patients in the seven studies, 1,480 had histologically proven follicular lymphoma; 260 had mantle cell lymphoma; and 203 were described as having indolent lymphoma (121) or lymphoplasmocytic/cytoid lymphoma or B-cell chronic lymphocytic leukemia (82). Five trials included untreated patients with advanced disease, and two trials included relapsed or refractory patients with follicular or mantle cell histology.
Various chemotherapy regimens were used in the trials, which precluded a reliable assessment of which chemotherapy regimen is best when used in combination with rituximab, or of the optimal number of cycles needed to treat patients with indolent lymphoma.
Toxicity in the studies was described as mild to moderate in each arm, but those receiving R-chemo were significantly more likely to have fever and leukocytopenia than those treated only with chemotherapy. There was no difference between groups with respect to frequencies of infection or thrombocytopenia.
Data from 1,914 available patients were analyzed for overall response. Among these patients with either indolent lymphoma or mantle cell lymphoma, 854 of 979 patients (87%) in the R-chemo group responded to treatment vs 673 of 935 patients (72%) in the chemotherapy-alone group—corresponding to a relative risk (RR) of response of 1.21 for the treatment group. The rate of complete response was significantly higher in patients treated with R-chemo (RR = 2.03). Analyses for disease control determined that R-chemo had a pooled hazard ratio of 0.62, which was significantly superior to chemotherapy alone.