The placebo-controlled, double-blind, inpatient trial analysed the safety, efficacy and tolerability of KarXT versus placebo in trial subjects in the US.
It enrolled a total of 252 schizophrenia patients aged 18 to 65 years with symptoms of psychosis.
These subjects were randomised into a 1:1 ratio to receive either a flexible dose of KarXT or a placebo twice daily (BID) for five weeks.
The variation from baseline in the Positive and Negative Syndrome Scale (PANSS) total score of KarXT versus placebo at week five was the trial’s primary endpoint.
PANSS is a scale to assess the severity of schizophrenia symptoms.
The variation from baseline in PANSS positive, PANSS negative and PANSS negative Marder factor subscale of KarXT versus placebo at week five were the key secondary endpoints of the trial.
According to the findings, KarXT offered a statistically significant and clinically meaningful 9.6-point decline in the PANSS total score versus placebo at week five, meeting the trial’s primary endpoint.
Furthermore, the therapy offered an early and sustained statistically significant decline of symptoms, as evaluated by PANSS total score, beginning at week two and lasting through all the trial’s timepoints.
The key secondary endpoints of the trial were also met and a statistically significant decline in schizophrenia’s positive and negative symptoms were reported.
KarXT was found to be well tolerated in the trial with an overall rate of treatment-emergent adverse events (TEAEs) being 75% compared to 58% for placebo.
An oral M1/M4-preferring muscarinic agonist, KarXT is being developed to treat psychiatric and neurological ailments, including schizophrenia and Alzheimer’s disease-associated psychosis.
Karuna Therapeutics CEO, president and chairman Steve Paul said: “We are thrilled that these topline results from the Phase III EMERGENT-2 trial confirm what was seen in our Phase III EMERGENT-1 trial and underscore the potential for KarXT, with its novel and unique mechanism of action, to redefine what successful treatment looks like for the 21 million people living with schizophrenia worldwide, and potentially usher in the first new class of medicine for these patients in more than 50 years.”
The company plans to file a New Drug Application with the US Food and Drug Administration for KarXT to treat schizophrenia mid-next year.
In November 2019, the company reported that KarXT showed promise in treating acute psychosis in schizophrenia patients in a Phase II trial.