Nelotanserin is a potent, selective 5-HT(2A) inverse agonist. Originally called ADP-125, the compound was developed by Arena Pharmaceuticals as a treatment for insomnia, but failed efficacy measures for this indication in Phase 2. In 2015, Axovant Sciences licensed this compound for development, renamed it nelotanserin, and began evaluating it in dementia with Lewy bodies (DLB). Both radioligand binding and functional inositol phosphate accumulation assays suggest that nelotanserin has low nanomolar potency on the 5-HT(2A) receptor with at least 30- and 5000-fold selectivity compared with 5-HT(2C) and 5-HT(2B) receptors, respectively. Nelotanserin dosed orally prevented (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI; 5-HT(2A) agonist)-induced hypolocomotion, increased sleep consolidation, and increased total nonrapid eye movement sleep time and deep sleep, the latter marked by increases in electroencephalogram (EEG) delta power. Nelotanserin has been used in trials studying the treatment of Lewy body dementia, visual hallucinations, dementia with Lewy bodies, and REM sleep behavior disorder.

Traxoprodil (CP-101,606) is a potent, selective N-Methyl-D-aspartate (NMDA) receptor (NR2B subunit) antagonist under development by Pfizer for its potential as a neuroprotectant in head injury and neurodegenerative disease. It is in phase II trials in the US and in phase I in Japan for the potential treatment of head injury, such as, Depressive Disorder, Major and Parkinson's Disease. CP-101,606 does not protect against glutamate-induced neurotoxicity in cultured cerebellar neurons, up to a dose of 10 uM. These results are consistent with CP-101,606 being a potent NMDA antagonist, selective for the type of NMDA receptor associated with the hippocampus. Some further investigation revealed that CP-101,606 was associated with a dose-related dissociation and amnesia. These results support the hypothesis that glutamate antagonists may be useful antidyskinetic agents. However, future studies will have to determine if the benefits of dyskinesia suppression can be achieved without adverse cognitive effects.

Trestolone is a synthetic androgen that inhibits the release of follicle-stimulating hormone and impairs spermatogenesis. Luteinizing hormone is also suppressed, which cuts production of testosterone. The azoospermia and oligospermia are reversible after discontinuation of trestolone. Trestolone has androgenic and anabolic properties and loss of secondary sex characteristics is not seen. Like testosterone, trestolone undergoes enzymatic aromatization to an estrogen. The use of trestolone instead of testosterone for androgen replacement therapy could have health-promoting effects by reducing the occurrence of prostate disease. Trestolone had been in phase II clinical trial for the andropause control. However, this development was discontinued.

Alvameline is a partial agonist of the M1 mAChR that also displays M2/M3 antagonist effects. It readily crosses the blood-brain barrier. It has an effect profile that makes it of interest to test its ability to counteract bladder overactivity in humans. Behaviorally, alvameline has been shown to significantly improve Morris water maze (MWM) performance in both young and ageimpaired rats. It failed to improve cognition in patients with mild to moderate Alzheimer's disease.

Palosuran, also known as ACT-058362, a potent and specific antagonist of the human UT receptor. Urotensin inhibition with palosuran was a promising alternative in pulmonary arterial hypertension. Palosuran inhibits binding to primate UT receptors in cell membranes but demonstrates differential activity in intact cells and vascular tissues. Palosuran improves pancreatic and renal function in diabetic rats. Phase-II clinical trials for diabetic nephropathies and cardiovascular disorders were discontinued.