Pimavanserin Prevents Relapse in Patients with Dementia-Related Psychosis
At a recent scientific meeting, Erin Foff of Acadia Pharmaceuticals Inc. described a study of pimavanserin (a selective serotonin inverse agonist/antagonist at 5-HT2A receptors) in dementia-related psychosis. Pimavanserin is currently approved in the United States for the treatment of hallucinations and delusions associated with Parkinson’s disease (PD). There is currently no Food and Drug Administration–approved treatment for dementia-related psychosis.
Enrolled patients had moderate-to-severe psychosis associated with Alzheimer’s disease, Parkinson’s, dementia with Lewy bodies, vascular dementia, or frontotemporal dementia. After a 12-week open label phase with flexible dosing and a target dosage of 34mg/day, 217 of the participants with a good response to pimavanserin were then randomized to continue pimavanserin or switch to placebo. The study was stopped early when a prespecified interim analysis revealed that pimavanserin was clearly superior to placebo. There was a more than 2.8-fold reduction in risk of relapse with pimavanserin compared to placebo in the double-blind period. Those on higher doses of 34mg/day showed a more than 3.4-fold reduced risk of relapse. Acadia will seek FDA approval for pimavanserin for the treatment of dementia-related psychosis.
Antipsychotic Drug Pimavanserin Seems to Reduce Psychosis in People with Alzheimer’s
The antipsychotic drug pimavanserin was approved by the US Food and Drug Administration last year as a treatment for hallucinations and delusions in Parkinson’s disease. Now it looks as though it may also help people with Alzheimer’s disease. Pimavanserin works differently than other antipsychotic medications—a selective serotonin inverse agonist, it acts at serotonin HT2A receptors to produce effects opposite to those that serotonin would produce at the same receptor.
In a trial of 181 patients with Alzheimer’s and psychotic symptoms, those who received 34 mg/day of pimavanserin had a significant improvement in psychotic symptoms in six weeks compared to those who received placebo.
Over 12 weeks of treatment, pimavanserin did not impair cognition, as atypical antipsychotics can do.
Pimavanserin was well tolerated. The most common side effects were falls, urinary tract infections, and agitation. Like other atypical antipsychotics, the drug carries a box warning from the FDA that there is an increased risk of death when the drug is used to treat older people with dementia-related psychosis.
The FDA has designated pimavanserin a breakthrough therapy and is giving it priority review. These designations can speed up the development and review of a drug and are granted when a drug looks like it will be substantially better or safer than existing treatments for a serious condition.
