For the first time in more than three decades, patients with schizophrenia have a fundamentally new treatment option. The U.S. Food and Drug Administration has approved KarXT (xanomeline-trospium), a novel oral medication that targets brain receptors differently than any existing antipsychotic, offering hope for millions living with this chronic mental health condition.
The approval follows five Phase 3 clinical trials involving over 1,800 patients. In the pivotal EMERGENT-2 trial, KarXT reduced schizophrenia symptoms by 9.6 points on the PANSS scale compared to placebo, a statistically significant improvement. Unlike current antipsychotics that block dopamine receptors, KarXT works by stimulating muscarinic acetylcholine receptors in the brain. This mechanism bypasses the severe side effects of traditional drugs, including weight gain, metabolic syndrome, and movement disorders that cause many patients to stop treatment.
For patients, the most meaningful difference may be in tolerability. The most common side effects of KarXT were gastrointestinal, such as nausea and constipation, which were generally mild to moderate. No significant weight gain or motor side effects were reported, a major departure from standard therapies. This could be life-changing for patients who have cycled through multiple medications due to intolerable side effects, often leading to relapse and hospitalization.
KarXT is taken twice daily with food. The drug was developed by Karuna Therapeutics, which designed the combination of xanomeline, a muscarinic agonist, with trospium, a peripheral anticholinergic agent that limits side effects outside the brain. The FDA has required a postmarketing study to evaluate long-term safety, including effects on the cardiovascular system.
The approval marks a new era in psychiatric medicine. Researchers are already studying whether KarXT could help with other conditions, including Alzheimer’s disease psychosis. For now, patients and clinicians have a long-awaited tool that works in a completely new way, offering a fresh start for a condition that has seen little innovation since the 1990s. The drug is expected to be available by late fall, with patient assistance programs to improve access.