Roche's neuroscience efforts have suffered a setback after its investigational schizophrenia drug bitopertin failed in a couple of late-stage studies.

The Swiss major announced that two Phase III trials of bitopertin in adults with persistent, predominant negative symptoms of schizophrenia failed to meet their primary endpoints. Specifically,  adding the oral glycine reuptake inhibitor to antipsychotic therapy did not significantly reduce negative symptoms such as include social withdrawal and lack of motivation at 24 weeks compared to placebo.

Sandra Horning, Roche's chief medical officer, said the results are disappointing for people with negative symptoms "because more effective treatments are needed for these debilitating effects of schizophrenia". She added that "we will await data from the remaining bitopertin studies in schizophrenia before deciding on next steps".

A third Phase III study evaluating bitopertin for negative symptoms of schizophrenia is ongoing, while three others looking at the drug for sub-optimally controlled symptoms, such as hallucinations and delusions, are ongoing. Data from the studies will be presented at upcoming medical meetings.

Roche noted that its neuroscience portfolio has 10 new molecular entities, including late-stage programmes in multiple sclerosis and Alzheimer's disease, as well as in schizophrenia.