July 24 2013 | By Márcio Barra
Roche has announced that its experimental leukemia drug GA101, or obinutuzumab, used in combination with chemotherapy, was better than Rituxan at helping people with chronic lymphocytic leukemia live longer without their disease worsening, according to the results from the second phase of the clinical trial. Both drugs were tested and compared in combination with chlorambucil.
The trial, named CLL11, is a phase III, multicenter, open-label, randomized three-arm study investigated in 781 previously untreated people with chronic lymphocytic leukemia and co-existing medical conditions who are in need of therapy. The study included two stages of analysis, with the first stage results being reported at the start of this month. Data from the first stage showed that patients taking Obinutuzumab had a 86%reduction in the risk of disease worsening or death when combined with chlorambucil chemotherapy compared to chlorambucil alone in previously untreated people with chronic lymphocytic leukemia .
Stage 2 enrolled an additional 192 patients to enable the final direct comparison of GA101 versus Rituxan, both in combination with chlorambucil. The results of second stage were reached well ahead of the trial completion date in 2014 as a result of the magnitude of difference seen between the two study arms. While no numbers were provided by Roche, it’s safe to assume that the differences between treatment arms in the second stage were similar to the first stage results.
Roche said final data from the study would be submitted to the American Society of Hematology’s annual meeting in December.
Obinutuzumab can be seen as Roche’s response to Rituxan losing its patent in Europe this year. Obinutuzumab, or GA101, is an antibody created to improve the immune system’s capability to attack and kill B cells, from which chronic lymphocytic leukemia originates. From the clinical trial data released thus far, the drug shows marked improvements over Roche’s own Rituxan, due to its increased potency in attacking B cells.
Roche is aiming for a December 20, 2013 approval date in the U.S, after being granted Priority Review Status by the FDA. This would be great news for Roche, as it would allow company to add a branded biologic to their portfolio sooner than later, as Rituxan will soon lose its patent protection. Rituxan added close to $6 billion in sales to the firm’s 2012 balance sheet.