Acadia abandons plans to expand pimavanserin indications 

March 12, 2024

Acadia Pharmaceuticals has pulled the plug on its efforts to expand its lead drug, pimavanserin, into additional indications following a phase 3 trial flop exploring the drug as treatment for negative symptoms of schizophrenia.

Pimavanserin, branded Nuplazid, failed to best placebo in the phase 3 ADVANCE-2 trial, according to Acadia. The 454-person trial used the NSA-16 scale, designed to measure change in the predominant negative symptoms that schizophrenia patients experience, which covers symptoms such as blunted affect, poor socialization and lack of motivation.​ 

Nuplazid was approved in the U.S. in 2016 and was the first and only treatment for hallucinations and delusions associated with Parkinson’s disease psychosis. Since that initial approval, San Diego-based Acadia has been pushing to expand the drug's label, in hopes of elevating the atypical antipsychotic to blockbuster status. The drug brought in $549.2 million in sales last year.

In 2021, the FDA struck down the company's bid to expand Nuplazid's use to patients with dementia-related psychosis. Despite meeting the primary and secondary endpoints of its study on patients with DRP, the FDA said that the company had failed to include enough patients with certain subtypes of dementia in its study. 

In August 2022, Acadia tried again, this time pushing to get approval for Nuplazid to treat hallucinations and delusions associated with Alzheimer’s disease psychosis. The FDA issued another CRL and recommended Acadia run an additional trial.

In terms of schizophrenia treatments, other drugmakers are poised to make a mark. Karuna Therapeutics is awaiting a September decision from the FDA for its potentially revolutionary schizophrenia treatment, KarXT. The orally administered drug uniquely targets M1/M4 muscarinic receptors, diverging from traditional treatments by avoiding dopamine and serotonin pathways. Its potential attracted the attention of Bristol Myers Squibb, which acquired Karuna for $14 billion back in December.