Obinutuzumab with chlorambucil helped patients with blood cancer live longer without disease worsening compared to rituximab

In elderly patients with chronic lymphocytic leukemia (CLL) taking obinutuzumab (Gazyva, Genentech), also known as GA101, in combination with chlorambucil lived nearly 1 year longer without worsening of their disease compared to rituximab in combination with chlorambucil, according to a study published online ahead of print in the New England Journal of Medicine.

A total of 781 patients were randomized into 3 treatment arms: chlorambucil alone, chlorambucil plus rituximab, chlorambucil plus obinutuzumab. The primary end point was progression-free survival. This study, conducted in cooperation with the German CLL Study Group, showed that median progression-free survival was 26.7 months for patients treated in the obinutuzumab-a novel glycoengineered type 2 CD20 antibody- arm compared with 15.2 months for those in the rituximab arm (HR 0.39, CI 0.31–0.49, P<.0001). No new safety signals were observed for either obinutuzumab or rituximab.

“It can be concluded from the study that chemoimmunotherapy with chlorambucil plus GA101 is a very active treatment in this difficult-to-treat patient population,” said Valentin Goede, MD, German CLL Study Group, University Hospital Cologne, Germany. “It therefore can be expected that this regimen and particularly the antibody will be increasingly used in elderly patients with CLL - GA101 may replace rituximab in this clinical setting.

“Together with another trial, this study establishes CD20 antibody-based chemoimmunotherapy in elderly patients with CLL and comorbidities,” Dr Goede continued. “The study demonstrates that the antibody features of GA101 [ie, the type 2 character and glycoengineering] translate into improved outcome compared to rituximab as the standard of care, thus making GA101 an attractive drug to be explored in other CLL indications and in combinations with other novel drugs for CLL.”