Rituximab plus gemcitabine and oxaliplatin in patients with refractory/relapsed diffuse large B-cell lymphoma who are not candidates for high-dose therapy. A phase II Lymphoma Study Association trial.

A previous pilot study with rituximab, gemcitabine and oxaliplatin showed promising activity in patients with refractory/relapsed B-cell lymphoma. We, therefore, conducted a phase II study to determine whether these results could be reproduced in a multi-institutional setting. This phase II study included 49 patients with refractory (n=6) or relapsing (n=43) diffuse large B-cell lymphoma. The median age of the patients was 69 years. Prior treatment included rituximab in 31 (63%) and autologous transplantation in 17 (35%) patients. International Prognostic Index at enrollment was >2 in 34 patients (71%). The primary endpoint was overall response rate after four cycles of treatment. Patients were planned to receive eight cycles if they reached at least partial remission after four cycles. After four cycles 21 patients (44%) were in complete remission and 8 (17%) in partial remission, resulting in an overall response rate of 61%. Factors significantly affecting overall response rate were early (<1 year) progression/relapse (18% versus 54%; P=0.001) and prior exposure to rituximab (23% versus 65%; P=0.004). Five-year progression-free and overall survival rates were 12.8% and 13.9%, respectively. Rituximab, gemcitabine and oxaliplatin were well tolerated with grade 3-4 infectious episodes in 22% of the cycles. These results are the first confirmation from a multicenter study that rituximab, gemcitabine and oxaliplatin provide a consistent response rate in patients with refractory/relapsed diffuse large B-cell lymphoma. This therapy can now be considered as a platform for new combinations with targeted treatments. This trial was registered at clinicaltrial.gov under #NCT00169195.