Long-term efficacy, safety, and tolerability of xanomeline and trospium chloride in schizophrenia: A 52-week, open-label trial (EMERGENT-5).

BACKGROUND

The M1/M4 muscarinic receptor agonist xanomeline combined with the peripherally restricted pan-muscarinic receptor antagonist trospium chloride is the first approved treatment for adults with schizophrenia with no direct D2 dopamine receptor blockade. Xanomeline and trospium chloride (KarXT) reduced symptoms and was generally well tolerated in adults with schizophrenia in three, 5-week, randomized, double-blind, placebo-controlled trials and a 52-week, open-label extension trial.

METHODS

EMERGENT-5 (NCT04820309) was a 52-week, open-label trial evaluating the long-term safety, tolerability, and efficacy of twice daily KarXT (maximum dose 125/30 mg) in psychiatrically stable adults with schizophrenia. Safety measures included treatment-emergent adverse events (TEAEs), vital signs, and laboratory parameters. Efficacy measures included change in Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression-Severity (CGIS).

RESULTS

Between June 2021-May 2024, 566 participants at 54 US sites received ≥1 dose of KarXT. Overall, 277/566 (48.9 %) participants completed the trial. A total of 466/566 (82.3 %) experienced ≥1 TEAE, the majority of which were mild or moderate in intensity; severe TEAEs were reported in 33/566 (5.8 %) participants. The most common TEAEs occurring in ≥5 % of participants were nausea (23.1 %), vomiting (20.3 %), constipation (18.0 %), hypertension (10.4 %), diarrhea and dry mouth (9.4 % each), dizziness (8.8 %), headache (8.1 %), dyspepsia (7.2 %), somnolence (6.2 %), weight decreased (5.7 %), and hyperhidrosis (5.1 %). KarXT improved PANSS total, PANSS positive and negative subscale, and CGI-S scores over the trial duration.

CONCLUSIONS

Psychiatrically stable adults with schizophrenia were safely switched from prior antipsychotics to KarXT with a trend toward symptom improvement over 1 year. The safety and tolerability profile of KarXT was consistent with observations in prior clinical trials; no new safety issues emerged.