Karuna Therapeutics has reported positive data from its Phase Ib clinical trial of KarXT (xanomeline-trospium) in adults with schizophrenia.

The eight-week, open-label, inpatient trial analysed the effect of KarXT on ambulatory blood pressure for 24 hours in these patients.

The variation in 24-hour average ambulatory systolic blood pressure from baseline at week eight was the trial’s primary endpoint.

Findings showed that KarXT treatment offered -0.59mmHg mean change in 24-hour ambulatory systolic blood pressure from baseline to week eight. 

Furthermore, 1.60mmHg was the upper bound of the two-sided 95% confidence range for the mean change. A clinically meaningful rise in blood pressure is thus ruled out. 

No meaningful variation in systolic blood pressure assessments at day and night were reported. 

The 24-hour average diastolic blood pressure and heart rate were in line with data from previous studies of KarXT for treating schizophrenia. 

In the trial, KarXT was also found to be well tolerated with a side effect profile similar to trials in the EMERGENT programme.

An investigational muscarinic antipsychotic, KarXT is being developed to treat Alzheimer’s disease-associated schizophrenia and psychosis.

Karuna Therapeutics chief medical officer Steve Brannan said: “The data from the trial confirms our findings from the EMERGENT trials that suggested KarXT is not associated with a sustained increase in blood pressure in adults with schizophrenia. 

“These results provide a more definitive characterisation of the cardiovascular safety profile of KarXT, which substantiates the existing clinical data to date and will supplement our NDA as part of the day 120 safety update, along with additional safety data, pending filing acceptance.”

In March 2023, the company reported that the Phase III EMERGENT-3 trial of KarXT in adults with schizophrenia met the primary endpoint.