Psychosis and cognition are symptom domains that cut across many different psychiatric and neurological disorders including schizophrenia and Alzheimer's. While Alzheimer's is condition that is widely talked about in the popular media due to the growing population and immense unmet need, schizophrenia is discussed less often despite the significant unmet need of the more than 3 million patients suffering form the disorder in the US alone. Schizophrenia is characterized by profound disruptions in thinking, affecting language, perception, and the sense of self, that typically includes psychotic episodes. Symptoms of schizophrenia can be divided into three categories: positive symptoms (e.g. hallucinations and delusions), cognitive symptoms (e.g. poor working memory) and negative symptoms (e.g., lack of emotional expression and social isolation).
Antipsychotics are the mainstay therapy for the treatment of schizophrenia. However, we believe that significant unmet need remains as currently used drugs can leave residual positive symptoms and do not treat the other symptom domains of schizophrenia. Available drugs also have serious side effects associated with them including potentially irreversible movement disorders, considerable weight gain, diabetes, risk of metabolic syndrome, and sedation.
Psychosis (hallucinations and delusions) can also be present in a number of different diseases such as Alzheimer’s disease, Parkinson's and Huntington's disease. Although Karuna is initially targeting psychosis in schizophrenia, KarXT has potential to more generally control psychosis.
Previous data in Alzheimer’s and Schizophrenia also suggests that xanomeline has a pro-cognitive benefit. Karuna intends to pursue the development of KarXT for cognitive symptoms across multiple disorders.