Roche's Investigational Schizophrenia Drug Bitopertin Phase III Studies "Disappointing"
Roche this week provided updates regarding the first two of six Phase III studies on its investigational schizophrenia drug bitopertin. Though the drug was generally well tolerated and maintained safety levels compared to Phase II trials, it did not significantly reduce negative symptoms in adult patients.
Bitopertin is an oral glycine inhibitor thought to possibly improve N-methyl-D aspartate (NMDA) receptor function. NMDA receptor function is speculated to be reduced in patients with schizophrenia and contributes to all core symptoms of the severe mental disorder.
Scizophrenia affects an estimated 26 million people around the world and is a leading cause of disability. The condition is characterized by positive, negative, and cognitive symptoms including hallucinations, social withdrawal, and difficulty in concentration.
Bitopertin is intended to target negative symptoms, but failed to meet primary endpoints. The results were based on the negative symptoms factor score of the positive and negative symptom scale (PANSS). Studies showed that adding bitopertin to antipsychotic therapy failed to significantly reduce negative symptoms at 24 weeks when compared to placebo.
The SearchLyte clinical development program used for the study was comprised of six Phase III studies assessing bitopertin as a possible add-on to anti-psychotic therapy. The therapy focused on schizophrenia symptoms not fully addressed by existing methods of treatment. Over 3,600 people across 32 countries took part in the studies.
Roche Global Product Development Head and Chief Medical Officer Sandra Horning, M.D., said, “These results are disappointing for people with negative symptoms because more effective treatments are needed for these debilitating effects of schizophrenia… We will await data from the remaining bitopertin studies in schizophrenia before deciding on next steps.”
As of present, three Phase III studies assessing bitopertin for sub-optimally controlled schizophrenia symptoms are underway.