Acadia Halts Psychosis Clinical Trial Early for Nuplazid

Shares of ACADIA Pharmaceuticals are up nearly 70% after the company announced it halted a Phase III psychosis trial early after its Parkinson’s disease drug Nuplazid hit primary endpoints and positioned the company to seek another potential regulatory approval.

This morning, San Diego-based ACADIA haled the HARMONY study assessing Nuplazid (pimavanserin) for the treatment of dementia-related psychosis. The company said the drug demonstrated a “highly statistically significant longer time to relapse” of psychosis with pimavanserin compared to placebo in a planned interim efficacy analysis. Following the early halt of the trial, ACADIA said it is planning to meet with the U.S. Food and Drug Administration in preparation of filing a supplemental New Drug Application. Also, the company said it intends to share the data from the HARMONY trial at upcoming medical meetings.

Nuplazid, a selective serotonin inverse agonist and antagonist preferentially targeting 5-HT2A receptors, was previously granted Breakthrough Therapy designation by the FDA. No drug has been approved by the FDA for the treatment of dementia-related psychosis. Nuplazid was previously approved by the FDA in 2016 for the treatment of hallucinations and delusions associated with Parkinson’s disease psychosis.

The HARMONY study was a 12-week stabilization study in which patients were treated with 34mg of Nuplazid daily. Following the stabilization period, patients who met pre-specified criteria for treatment response were randomized into the double-blind period of the study to continue their Nuplazid treatment or were switched to placebo. They were then followed for up to 26 weeks or until a relapse of psychosis occurred. The primary endpoint in the study was time to relapse in the double-blind period.

ACADIA President Serge Stankovic said the company is excited that the trial stoppage brings them one step closer to being able to offer patients with dementia-related psychosis a “critically needed treatment option.”