Roche today announced that two phase III studies of its investigational medicine bitopertin (RG1678) in adults with persistent, predominant negative symptoms of schizophrenia failed to meet their primary endpoints, based on the negative symptoms factor score of the positive and negative symptom scale (PANSS). Negative symptoms include social withdrawal and lack of motivation.
In the studies, adding bitopertin to antipsychotic therapy did not significantly reduce negative symptoms at 24 weeks compared to placebo. Bitopertin was generally well tolerated and its overall safety profile was similar to that seen in the previously reported phase II trial (NN20372).
A third phase III study evaluating bitopertin for persistent, predominant negative symptoms of schizophrenia is ongoing. In addition, three phase III studies investigating bitopertin for sub-optimally controlled symptoms of schizophrenia are in progress. Sub-optimally controlled symptoms, such as hallucinations and delusions, are symptoms that do not resolve despite treatment with an antipsychotic.
“These results are disappointing for people with negative symptoms because more effective treatments are needed for these debilitating effects of schizophrenia,” said Sandra Horning, M.D., Chief Medical Officer and Head of Global Product Development at Roche. “We will await data from the remaining bitopertin studies in schizophrenia before deciding on next steps.”
Data from the studies will be submitted for presentation at upcoming medical meetings.