Amiglumide [CR 1795] is an amino acid derivative with cholecystokinin A antagonist activity. It has potential use for treating gastrointestinal disorders, pancreatitis and biliary dyskinesia. Amiglumide was developed in preclinical trials with Rottapharm in Italy.

FENIMIDE, a succinimide derivative, is an antipsychotic drug. It is not found in any pharmaceutical preparations sold in the US. It was found that FENIMIDE produced a sedative effect prior to deeper central nervous system depression.

Racemethorphan is racemic mixture of Dextromethorphan and Levomethorphan. Racemethorphan is listed under the Single Convention on Narcotic Drugs 1961 and is therefore listed in the United States as a Controlled Substance, specifically as a Narcotic in Schedule II. Dextromethorphan is a non-narcotic morphine derivative widely used as an antitussive. Dextromethorphan is a cough suppressant in many over-the-counter cold and cough medicines. In 2010, the FDA approved the combination product dextromethorphan/quinidine for the treatment of pseudobulbar affect. Dextromethorphan suppresses the cough reflex by a direct action on the cough center in the medulla of the brain. Levomethorphan is an opioid analgesic of the morphinan family that has never been marketed.

Alnespirone [S 20499] is a potent and full agonist at pre- and postsynaptic serotonin 1A receptors. Alnespirone is the (+)-enantiomer, S 20244 is the racemate. In animal models, alnespirone demonstrated both anxiolytic and antidepressant activity and was undergoing phase II trials in these indications with Servier in France. However, development of Alnespirone was discontinued for anxiety disorders and major depressive disorder.

ABT-102 is a selective antagonist of transient receptor potential vanilloid type 1 (TRPV1), designed for the treatment of nociceptive pain. ABT-102 potently blocks multiple modes of TRPV1 receptor activation and effectively attenuates downstream consequences of receptor activity.

GSK-163090 is potent, selective, and orally active 5-HT1A/B/D receptor antagonist. GSK163090 was found to combine potent in vivo activity with a strong preclinical developability profile, and on this basis it was selected as a drug candidate with the aim of assessing its potential as a fast-onset antidepressant/anxiolytic. GSK-163090 had been in phase II clinical trials by GlaxoSmithKline for the treatment of major depressive disorder (MDD) and anxiety disorders. However, this research has been discontinued.

Lensiprazine (SLV314) is a potent D2 receptor antagonist in vitro and have a considerable in vitro affinity for serotonin reuptake sites. It capable of antagonizing apomorphine-induced climbing behavior, disrupting CAR activity and potentiating 5-hydroxytryptophan (5-HTP) behavior. SLV314 has also been found to antagonize amphetamine- and ketamine-stimulated locomotor activity and methylphenidate-induced gnawing and stimulated behaviors, furthermore, a significant dose discrepancy was seen between the antipsychotic and cataleptogenic effects of SLV314. Lensiprazine demonstrated putative antipsychotic and selective serotonin reuptake inhibitor potential.

Doliracetam possesses activity on the central nervous system. It has cognition enhancing properties and might be useful in the treatment of Alzheimer’s disease and epilepsy

GW842166 is a pyrimidine cannabinoid 2 (CB2) receptor agonist that was being developed by GlaxoSmithKline for the treatment of inflammatory pain. It has potent analgesic, anti-inflammatory and anti-hyperalgesic actions in animal models, but without cannabis-like behavioural effects due to its extremely low affinity for the CB1 receptor. GW842166 shows similar potency and efficacy for rat and human recombinant CB2 receptors with EC50 of 91 nM and 63nM, respectively. GW842166 is in Phase 2 trial.

ISPRONICLINE is a partial agonist at the a4b2 subtype of nicotinic acetylcholine receptors (nAChRs) without interaction with other nAChRs or other receptor systems. It has antidepressant, nootropic, and neuroprotective effects. It progressed to phase II clinical trials for the treatment of dementia and Alzheimer's disease but is no longer under development.