Cobenfy, a drug Bristol Myers Squibb acquired in a $14 billion deal, failed to show added benefits in patients with schizophrenia when used alongside standard treatments.

Bristol Myers Squibb has announced that its schizophrenia drug Cobenfy did not meet the main goal in a late-stage clinical trial. The trial was designed to evaluate whether Cobenfy could help patients who had stopped responding to their current antipsychotic medications. The drug, also known as KarXT, was acquired through the company’s $14 billion purchase of Karuna Therapeutics and has been viewed as a major part of the company’s growth strategy.

The study enrolled adults aged 18 to 65 with schizophrenia who were already on stable antipsychotic treatment. Over six weeks, the trial measured whether adding Cobenfy led to better symptom control. Results showed only a two-point reduction in symptoms compared to a placebo. Analysts had anticipated a more substantial improvement to support broader use of the drug.

Cobenfy, approved last year, is unique in that it targets cholinergic receptors rather than the dopamine receptors that most existing antipsychotics act on. This mechanism had raised expectations that it could complement existing therapies. However, no current medications have approval for use as an add-on treatment in schizophrenia, which had placed Cobenfy in a potential first-mover position.

Market reaction was swift, with Bristol Myers shares dropping nearly 5% after the announcement. William Blair analyst Matt Phipps said the results were a "blow for uptake curve," though he noted that the market remains large.

Bristol Myers stated it will complete a full analysis of the data and plans to share detailed findings at an upcoming medical conference. The company has not yet disclosed whether it will adjust its development plans for the drug. For now, the anticipated expansion of Cobenfy’s role in schizophrenia treatment remains uncertain.