Obinutuzumab Significantly Improves PFS in CLL

Hal Barron, MD

The first set of results from a phase III clinical trial found that obinutuzumab (also known as GA101) plus chlorambucil chemotherapy significantly improved progression-free survival (PFS) in patients with chronic lymphocytic leukemia (CLL), according to an announcement from the drug’s investigator Genentech.

Though Genentech did not announce specific results from the trial, the company plans to have the results presented at an upcoming medical meeting, according to a statement. Additionally, the company announced that they plan to submit the results of this trial that have been obtained thus far to the FDA for potential regulatory approval.

Obinutuzumab is a type 2 anti-CD20 monoclonal antibody designed to treat B-cell malignancies. Research is being done to determine whether obinutuzumab is superior to rituximab in both CLL and non-Hodgkin’s lymphoma.

In the phase III CLL11 trial, obinutuzumab plus chlorambucil was compared with rituximab plus chlorambucil and chlorambucil alone in patients with previously untreated CLL. The results of Stage 1 of the study only represent the comparison of obinutuzumab and chlorambucil with chlorambucil alone. Stage 2 results concern obinutuzumab and chlorambucil compared with rituximab and chlorambucil and will be reported at a later date. Though survival results have not become available as of yet, Genentech did note that no new safety events were reported for the obinutuzumab or rituximab arms of the study up until the time of this particular analysis.

“The improvement in progression-free survival seen with GA101 is encouraging for people with CLL, a chronic illness of older people for which new treatment options are needed,” said Hal Barron, MD, chief medical officer and head of Global Product Development for Genentech, in a statement. “GA101 demonstrates our ongoing commitment to the research and development of new medicines for this disease."