Pimavanserin
Blocks the serotonin 5-HT2A receptor. Tested for negative symptoms of schizophrenia; its phase 3 trial found no benefit, and its maker stopped trials in 2024.
At a glance
- Type
- Medicine: serotonin 5-HT2A receptor inverse agonist
- Used for
- Tested as an add-on for negative symptoms of schizophrenia
- Status
- Development stopped, for negative symptoms, after its phase 3 trial found no benefit in 2024
- Administration
- Capsules, once a day, added to an antipsychotic
Clinical summaryFor health professionals
What it is
Pimavanserin blocks the serotonin 5-HT2A receptor and dampens its baseline activity. It was tested for negative symptoms, such as low motivation and blunted emotion, added to the antipsychotic people already took.1
How well it works
In a phase 2 trial at 83 sites, 65 of them in Europe, 403 people with mainly negative symptoms took pimavanserin or a placebo for 26 weeks, and negative symptoms improved slightly more on pimavanserin.1 A phase 3 trial in 454 people did not confirm this: negative symptoms improved by 11.8 points on pimavanserin and 11.1 on placebo.2 Its maker, Acadia, said it would conduct no further trials.2
Side effects
In the phase 3 trial, side effects were less common on pimavanserin than on placebo: 30 in 100 people against 40 in 100.2
Alternatives
Roluperidone (opens in a new tab), which also blocks 5-HT2A, is in a phase 3 trial for negative symptoms.
What we don’t know yet
- Why the benefit seen in the first trial did not recur.
