Pimavanserin – Major Depressive Disorder


Pimavanserin is a proprietary small molecule that we are advancing to Phase 3 development for major depressive disorder (MDD). Pimavanserin is a selective serotonin inverse agonist (SSIA) preferentially targeting 5-HT2A receptors. Its distinct mechanism of action targets serotonergic 5-HT2A receptors that may play a role in depression.

About Major Depressive Disorder (MDD)

According to the National Institute of Mental Health, MDD affects approximately 16 million adults in the United States, with approximately 2.5 million adults treated with adjunctive therapy. MDD is a condition characterized by depressive symptoms, such as a depressed mood or a loss of interest or pleasure in daily activities for more than two weeks, as well as impaired social, occupational or other important functioning. The majority of people who suffer from MDD do not respond adequately to initial antidepressant therapy.


In October 2018, we announced positive top-line results from CLARITY, a Phase 2 study evaluating pimavanserin for adjunctive treatment in 207 patients with MDD who had a confirmed inadequate response to existing first-line, SSRI or SNRI, antidepressant therapy.

We plan to meet with the FDA and initiate two Phase 3 clinical trials with pimavanserin in adjunctive MDD in the first half of 2019.