On December 6, 2023, AbbVie agreed to buy Cerevel Therapeutics for about $8.7 billion, a pipeline that included emraclidine, an experimental schizophrenia drug that works on the muscarinic M4 receptor. Sixteen days later Bristol Myers Squibb agreed to buy Karuna Therapeutics for $14.0 billion, for a drug that acts on both M1 and M4 receptors and was already under FDA review.
AbbVie completed the Cerevel deal on August 1, 2024. On November 11, 2024, 102 days later, it announced that both Phase 2 trials of emraclidine had missed their main goal. AbbVie recorded a $4.5 billion impairment on the drug for 2024. This page sets out what the filings and papers say, and the questions an audit would put to the evidence. Every figure was read from the cited source. It does not claim that an audit would have prevented the loss.
| Dec 6, 2023 | AbbVie announces it will buy Cerevel for $45.00 per share in cash, a total equity value of about $8.7 billion. Its release describes emraclidine as a positive allosteric modulator of the muscarinic M4 receptor. It says that in a Phase 1b study emraclidine “has shown promising efficacy and safety in schizophrenia,” and that two Phase 2 trials designed to be registration-enabling were being completed. | AbbVie press release, Dec 6 2023 |
| Dec 22, 2023 | Bristol Myers Squibb announces it will buy Karuna for $330.00 per share, a total equity value of $14.0 billion ($12.7 billion net of cash acquired). Its release calls Karuna’s drug KarXT (xanomeline-trospium) a first-in-class M1/M4 muscarinic receptor agonist, with an FDA decision date of September 26, 2024. | Bristol Myers Squibb release, Dec 22 2023 |
| Mar 18, 2024 | Bristol Myers Squibb completes the Karuna acquisition. | Bristol Myers Squibb release, Mar 18 2024 |
| Aug 1, 2024 | AbbVie completes the Cerevel acquisition. | AbbVie 10-K, fiscal 2024 |
| Nov 11, 2024 | AbbVie announces that its two Phase 2 EMPOWER trials of once-daily emraclidine in adults with schizophrenia experiencing an acute worsening of psychotic symptoms did not meet their primary endpoint: a statistically significant improvement over placebo in the change in PANSS total score at week 6. | AbbVie 8-K, Jan 10 2025 |
| Jan 10, 2025 | AbbVie reports it will record an impairment on the emraclidine intangible asset, estimated at about $3.5 billion after tax, and that about $3.6 billion of other Cerevel intangible assets remain under monitoring. | AbbVie 8-K, Jan 10 2025 |
| Fiscal 2024 | AbbVie’s annual report records a $4.5 billion intangible asset impairment charge related to emraclidine, within operating losses of $4.9 billion attributable to Cerevel. | AbbVie 10-K, fiscal 2024 |
The January 2025 filing gave an after-tax estimate of about $3.5 billion; the annual report records $4.5 billion. Equity value is not the same as the value assigned to emraclidine.
| 1997 | A 6-month trial of xanomeline in 343 people with Alzheimer disease, described in its abstract as an “m1 and m4 selective” muscarinic agonist. Behavioral symptoms such as delusions and hallucinations fell in a dose-dependent way. In the high-dose arm, 52% of patients stopped treatment because of adverse events, mostly gastrointestinal. | Bodick et al., Arch Neurol 1997, PMID 9109749 |
| 2024 | The EMERGENT-2 Phase 3 trial of KarXT in 252 people with acute schizophrenia, funded by Karuna. The paper describes xanomeline as a “dual M1 and M4-preferring” agonist. The primary endpoint was met: PANSS total score fell 21.2 points on KarXT versus 11.6 on placebo, a difference of 9.6 points (95% CI −13.9 to −5.2) at week 5. | Kaul et al., Lancet 2024, PMID 38104575 |
The first two questions concern evidence that was public when the deal was signed. The last two draw on later filings. None is a finding that the deal was wrong. The method behind them, tracing each load-bearing claim to its primary source and tagging each link supported, partial, contradicted or missing, is described on the main page.
A Phase 2 readout is a binary event. A trial that reads out 102 days after close (August 1 to November 11, 2024) carries a risk that documents can describe but cannot fully remove. What an audit can do is show, before the money moves, which evidence supports the mechanism being bought and which is borrowed from a neighboring one.