Combining an anti-CD20 monoclonal antibody with conventional chemotherapy has demonstrated survival benefits in patients with a previously untreated B-cell malignancy, according to research published in The New England Journal of Medicine (October 2017;377:1331-1344).
Previous research has demonstrated the positive survival effects of combining the anti-CD20 monoclonal antibody rituximab with chemotherapy in patients with newly diagnosed follicular lymphoma. However, the effects of obinutuzumab—also an anti-CD20 monoclonal antibody with demonstrated antitumor activity in other malignancies—in combination with chemotherapy has yet to be studied.
Robert Marcus, MD, King’s College Hospital (London, UK), and colleagues conducted a trial (GALLUM) to compare the effects of obinutuzumab-based chemotherapy with rituximab-based chemotherapy in patients with previously untreated advanced-stage follicular lymphoma. A total of 1202 patients were randomized to undergo induction treatment with either the obinutuzumab regimen (n = 601 patients) or the rituximab regimen (n = 601 patients). All patients who responded to induction therapy received maintenance treatment with the same antibody for up to 2 years.
After a median follow-up of 34.5 months, researchers found that patients in the obinutuzumab arm had a significantly lower risk of progression-free survival (PFS), relapse, or death. The 3-year PFS rate was 80% in the obinutuzumab arm, compared with 73.3% in the rituximab arm. The hazard ration for progression, relapse, or death was 0.66 (95% CI, 0.51-0.85; P = .001).
Researchers also reported that deaths were higher in the rituximab arm (n = 46) than in the obinutuzumab arm (n = 35), resulting in a hazard ratio for death of 0.75 (95% CI, 0.49-1.17; P = .21). While response rates were comparable at the end of the induction phase between the obinutuzumab and rituximab arms (88.5% vs 86.9%, respectively; P = .33), event-free survival favored patients in the obinutuzumab arm (hazard ratio, 0.65; 95% CI, 0.51-0.83; P < .001).
Adverse events were more common in the obinutuzumab arm, researchers acknowledged (74.6% vs 67.8%, respectively).
“The results of this large collaborative trial show that the replacement of rituximab with obinutuzumab in the context of immunochemotherapy and maintenance therapy in patients with previously untreated follicular lymphoma resulted in significantly longer PFS,” the authors wrote in their concluding remarks.—Zachary Bessette