Discovery and Preclinical Characterization of Usmarapride (SUVN-D4010): A Potent, Selective 5-HT Receptor Partial Agonist for the Treatment of Cognitive Deficits Associated with Alzheimer's Disease.

A series of oxadiazole derivatives were synthesized and evaluated as 5-hydroxytryptamine-4 receptor (5-HTR) partial agonists for the treatment of cognitive deficits associated with Alzheimer's disease. Starting from a reported 5-HTR antagonist, a systematic structure-activity relationship was conducted, which led to the discovery of potent and selective 5-HTR partial agonist 1-isopropyl-3-{5-[1-(3-methoxypropyl) piperidin-4-yl]-[1,3,4]oxadiazol-2-yl}-1H-indazole oxalate (Usmarapride, ). It showed balanced physicochemical-pharmacokinetic properties with robust nonclinical efficacy in cognition models.

Samelisant (SUVN-G3031), a potent, selective and orally active histamine H3 receptor inverse agonist for the potential treatment of narcolepsy: pharmacological and neurochemical characterisation.

Rationale: Samelisant (SUVN-G3031) is a potent and selective histamine H3 receptor (H3R) inverse agonist with good brain penetration and oral bioavailability.

Objectives: Pharmacological and neurochemical characterisation to support the utility of Samelisant (SUVN-G3031) in the treatment of sleep-related disorders like narcolepsy.

Methods: Samelisant (SUVN-G3031) was tested in rat brain microdialysis studies for evaluation of modulation in histamine, dopamine and norepinephrine.

Discovery and Development of 3-(6-Chloropyridine-3-yloxymethyl)-2-azabicyclo[3.1.0]hexane Hydrochloride (SUVN-911): A Novel, Potent, Selective, and Orally Active Neuronal Nicotinic Acetylcholine α4β2 Receptor Antagonist for the Treatment of Depression.

A series of chemical optimizations guided by in vitro affinity at the α4β2 receptor in combination with selectivity against the α3β4 receptor, pharmacokinetic evaluation, and in vivo efficacy in a forced swim test resulted in identification of 3-(6-chloropyridine-3-yloxymethyl)-2-azabicyclo[3.1.0]hexane hydrochloride (, SUVN-911) as a clinical candidate.