After five weeks of treatment in the trial that enrolled just over 250 participants, those who were given Karuna's drug experienced significant reductions on a scoring system used to measure the severity of schizophrenia symptoms., as compared to those given a placebo.

The drug arm of the study, in particular, showed an 8.4-point higher decline on the scale, which goes as high as 210 points and measures both positive and negative symptoms of schizophrenia.

The findings add to a growing body of evidence that Karuna's drug, known as KarXT, could be a valuable new option for schizophrenia patients. It previously met the primary objectives of two other mid to late-stage trials, and Karuna intends to officially request FDA approval in the middle of this year.

Unlike other schizophrenia treatments, which target the mood-regulating chemicals dopamine and serotonin, KarXT targets two members of a protein family that regulate whether acetylcholine gets released in the brain. Acetylcholine is a neurotransmitter involved in many critical processes for brain function.

Karuna plans to launch its drug in 2024. According to the company, three million people in the United States and 21 million more worldwide have schizophrenia.