About half of all blood cancers are those of the lymphatic system, which are classified as either Hodgkin or non-Hodgkin lymphoma. There are many types of non-Hodgkin lymphoma, including follicular lymphoma (the second most common type) and mantle cell lymphoma (a rare and difficult-to-treat cancer). While the current standard of care for patients with non-Hodgkin lymphoma is a chemotherapy regimen called CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone) plus the immunotherapy rituximab, it has been linked to high toxicity rates. 

However, promising results, presented at the American Society of Hematology Annual Meeting, have been observed in two phase II studies evaluating a new combination treatment consisting of a chemotherapy agent called bendamustine plus rituximab in patients with relapsed or refractory indolent (slow-growing) or mantle cell lymphoma. In order to further investigate the role of bendamustine and rituximab combination therapy, researchers from the German Study Group Indolent Lymphoma (StiL) initiated a multicenter, randomized, phase III study to compare the efficacy and safety of bendamustine plus rituximab versus CHOP plus rituximab as a potential first-line therapy for patients with follicular, indolent, and mantle cell lymphoma.

Five hundred forty-nine patients were randomised to receive one dose of rituximab (375 mg/m2) plus two doses of bendamustine (90 mg/m2) every 28 days or the standard CHOP regimen every 21 days for a maximum of six cycles. The types of non-Hodgkin lymphoma were equally distributed between the two treatment regimens (55 percent and 56 percent for follicular lymphoma, 18 percent and 19 percent for mantle cell lymphoma, and 27 percent and 24 percent for other indolent lymphomas, respectively). The primary objective of the study was to improve progression-free survival for patients with non-Hodgkin lymphoma.

Study results revealed that bendamustine and rituximab combination therapy significantly improved progression-free survival and complete remission rates while showing less toxicity as compared with the current standard treatment. The median progression-free survival for bendamustine and rituximab combination therapy was 54.8 months compared with 34.8 months for CHOP and rituximab combination therapy. The complete remission rate of 40.1 percent for bendamustine and rituximab combination therapy was significantly higher than the 30.8 percent achieved with CHOP and rituximab combination therapy. As predicted, a higher frequency of serious adverse events was seen with the CHOP and rituximab combination therapy, such as neutropenia (10.7 percent versus 46.5 percent) and leukocytopenia (12.1 percent versus 38.2 percent). The bendamustine and rituximab combination therapy was better tolerated by patients as evidenced by lower rates of treatment side effects such as hair loss (15 percent versus 62 percent), infectious complications (95 versus 121 patients), nerve damage (18 versus 73 patients), and episodes of inflammation in the mucous lining of the mouth (16 versus 47 patients).

"While the CHOP and rituximab combination is the current standard of care, it is frequently associated with serious adverse events and more side effects, as was further shown in this study," said lead author Dr. Mathias J. Rummel, Head of the Department for Haematology at the University Hospital in Giessen, Germany. "These promising results suggest that the combination of bendamustine and rituximab has the potential to become the new standard, first-line treatment option for patients with these non-Hodgkin lymphoma entities."

Source: American Society of Hematology