BMS Sees Early ROI for $14B Karuna Buy with Phase III Schizophrenia Win

Bristol Myers Squibb_hapabapa/iStock

Pictured: Bristol Myers Squibb office in Brisbane, California/iStock, hapabapa

Bristol Myers Squibb on Saturday unveiled interim data from the Phase III open-label EMERGENT-4 study, showing that the investigational antipsychotic KarXT (xanomeline and trospium) can elicit significant and sustained symptom improvement in patients with schizophrenia.

The results, presented at the Annual Congress of the Schizophrenia International Research Society (SIRS 2024), demonstrated that more than 75% of KarXT-treated patients saw at least a 30% improvement in symptoms at 52 weeks of follow-up, as measured by the Positive and Negative Syndrome Scale (PANSS) total score. The drop in PANSS score was 33.3 points from baseline.

Patients receiving KarXT also demonstrated a 1.7-point improvement in the Clinical Global Impression-Severity score. This score shift represents an improvement from being “markedly ill” at baseline to “moderately” or “mildly” ill after 1 year, according to BMS.

Roland Chen, senior vice president and head of immunology, cardiovascular and neuroscience development at BMS, in a statement said that EMERGENT-4’s data further establish KarXT’s ability to elicit a “continued and consistent meaningful reduction in symptoms of schizophrenia” through 52 weeks of follow-up in an outpatient setting.

The company will share more data from the EMERGENT program “later this year,” Chen said, adding that BMS will also have “continued conversations” with the FDA for KarXT’s ongoing review.

Originally developed by Karuna Therapeutics, KarXT is a muscarinic antipsychotic which, unlike existing schizophrenia therapies, does not block dopamine receptors. Instead, the treatment activates both the M1 and M4 Muscarinic acetylcholine receptors, in turn inducing improvements in the positive and negative symptoms of schizophrenia.

In December 2023, BMS acquired Karuna for $14 billion. KarXT is currently being reviewed by the FDA, with a PDUFA date in September 2024.

On Saturday at the SIRS 2024 Annual Congress, BMS also presented long-term safety data for KarXT from its Phase III EMERGENT clinical development program. Pooling data from EMERGENT-4 and EMERGENT-5—both of which are open-label studies—showed that KarXT was generally well-tolerated over 52 weeks of treatment, with an adverse event profile consistent with what had been established in prior trials.

KarXT also had an overall favorable effect on patients’ weight and metabolic profiles, with most patients losing weight after 52 weeks. However, KarXT did not meaningfully change total cholesterol, triglyceride and HbA1c levels.

Chen in a separate statement called these long-term data “extremely encouraging,” signaling that KarXT is not associated with “burdensome side effects” even after one year of follow-up. This safety and tolerability profile “underscores its potential to provide a meaningful and differentiated option for people living with schizophrenia,” he said.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at or

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