Four studies (n=805 patients) were included in the review, including two RCTs of patients receiving first-line therapy and two prospective single-group studies evaluating relapsed patients. One RCT (n=428 patients) compared response rates of R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone) and CHOP; the other RCT (n=321 patients) evaluated R-CVP (rituximab, cyclophosphamide, vincristine and prednisone) and CVP. One single group study (n=16 patients) evaluated R-CHOP in relapsed patients; the other single group study examined R-CHOP in new patients and relapsed patients.
Patients receiving R-CVP as first-line therapy recorded statistically significant higher rates of attaining a complete response than patients receiving R-CHOP (R-CVP 41.3% versus R-CHOP 19.7%; OR 2.86, 95% CI 1.81 to 4.51). Higher complete response rates were also observed in relapsed patients receiving R-CVP as second-line treatment, although the difference was not statistically significant (R-CVP 41.3% versus R-CHOP 32.1%; OR 1.48, 95% CI 0.99 to 2.22).
Higher numbers of patients achieved partial responses to treatment with R-CHOP compared with R-CVP in patients receiving first-line treatment (R-CHOP 76.2% versus R-CVP 40.6%; OR 5.45, 95% CI 2.51 to 11.83) and for all patients analysed (total response R-CHOP 96.0% versus R-CVP 81.9%; OR 5.54, 95% CI 2.69 to 11.40).