Nelotanserin

Nelotanserin is a drug developed by Arena Pharmaceuticals which acts as an inverse agonist on the serotonin receptor subtype 5-HT_2A and was under development for the treatment of insomnia. It was shown to be effective and well tolerated in clinical trials, but development was halted in December 2008 because the substance did not meet the trial's effectiveness endpoints. Research continues on newer analogues which may potentially be more successful.

Pharmacology

The elimination half-life of nelotanserin is dose-dependent and ranges from 3.9hours at 10mg to 23.2–23.7hours at doses of 80–160mg.

Later, nelotanserin was repurposed for the treatment of Lewy body dementia by Axovant Sciences. In late 2018, the company announced that while nelotanserin was generally well-tolerated by LBD patients in a small Phase 2 clinical trial for the treatment of REM sleep behavior disorder and there were positive indications on some secondary trial outcomes such as sleep diaries and some polysomnogram sleep parameters, the drug failed to meet its primary endpoint of reducing the frequency of RBD episodes and would be discontinued.