Fipamezole is a fluorine substituted imidazole compound with high antagonist specificity for the presynaptic alpha2-adrenoceptor. There were no significant differences between the affinity of Fipamezole for the different subtypes, thus characterizing Fipamezole as a non-subtype–selective alpha2 antagonist. Fipamezole had been in phase III clinical trials for the treatment of dyskinesia associated with Parkinson’s disease. Detected side effects are hypertension, nausea, vomiting, dysgeusia, facial flushing.

AV608, a 4-aminopiperidine derivative, is a selective, specific, long-acting, orally active and potent nonpeptidic antagonist of the NK-1 receptor. AV-608 had been in phase II clinical trials for the treatment of social phobia and overactive bladder (OAB). This compound was originally discovered by Novartis, and then licensed to Areva Pharmaceuticals in October 2003. Addition this drug was in phase I clinical trial for the treatment of Irritable Bowel Syndrome (IBS), this disease is characterized by chronic abdominal pain and frequent comorbid anxiety. The substance P ⁄ neurokinin-1 receptor system is implicated in the regulation of both pain and anxiety, suggesting a potential therapeutic target in IBS. However, the researches on this drug candidate were discontinued in 2010.

Chlorpromazine Phenolphthalinate is Phenolphthalinate salt of psychotropic agent Chlorpromazine marketed as Wintermin by Japanese pharmaceutical company Shionogi Inc for treating certain mental or mood disorders. Chlorpromazine is a psychotropic agent indicated for the treatment of schizophrenia and other central nervous system disease

Dihydrexidine, a novel full efficacy D1 dopamine receptor agonist. Dihydrexidine was shown to stimulate cyclic AMP synthesis just as well or better than dopamine. It was the first dopamine D1 receptor agonist that had potent antiparkinsonian activity in a primate model of Parkinson's disease. Dihydrexidine produces hypothermia. Dihydrexidine has been shown to alleviate cognitive deficits or enhance cognitive performance in a number of animal models of cognition. It is under investigation for the improving the cognitive and working memory deficits in schizophrenia and schizotypal disorder.

Basmisanil (INN) (developmental code names RG-1662, RO5186582) is a highly selective inverse agonist/negative allosteric modulator of α5 subunit-containing GABAA receptors which is under development by Roche for the treatment of cognitive impairment associated with Down syndrome. The phase II trials were recently terminated due to lack of efficacy. This outcome suggests either that the α5-NAM was insufficiently effective to restore neuronal plasticity or alternatively that the hypothesis of excessive GABAergic inhibition obstructing neuronal plasticity does not extend to individuals with DS.

Talopram (Lu 3-010) is a selective inhibitor norepinephrine transporter belonging to the antidepressants of the thymoleptic group.

Cobalt protoporphyrin (CoPP) is a potent HO-1 inducer and generally known to be an antioxidant in various cell types. CoPP has been shown to downregulate various cytochrome P450 isoforms, and various mechanisms of action have been attributed to its ability to induced HO- 1. It has also been used to promote endogenous carbon dioxide (CO) generation and protect against myocardial infarction in vivo. CoPP also participated in regulating the inflammatory response in CNS which mainly suppressed inflammatory component. It has been demonstrated that CoPP reduced LPS/Interleukin 13 (IL-13)-induced microglial death.

Tracazolate (ICI 136,753), a pyrazolopyridine, is a non-benzodiazepine with anxiolytic-like activity in animal models. It is known to interact with gamma-aminobutyric acid (GABA)(A) receptors, adenosine receptors, and phosphodiesterases. Its intrinsic efficacy, potentiation, or inhibition is determined by the nature of the third subunit (gamma1-3, delta, or epsilon) within the GABA(A) receptor complex.

CHF-5074 is a small molecule with a unique microglial modulating mechanism of action capable of selectively reducing pro-inflammatory activities of microglial cells while increasing their ability to remove neurotoxic amyloid beta (“Aβ”) aggregates in the brain by phagocytosis. CHF-5074 reduces Aβ42 and Aβ40 secretion, with an IC50 of 3.6 and 18.4 μM, respectively. Microglia are small cells that migrate through the brain to remove waste products, such as amyloid aggregates that cause inflammation and irreversible damage to nerve cells. Chronic dysfunction of microglia is increasingly believed to play an important role at the very beginnings of Alzheimer’s disease. The results from Chiesi’s human clinical studies corroborate the large body of data from published preclinical studies. In Alzheimer’s disease transgenic mouse models, CHF-5074 was shown to reduce neuroinflammation, inhibit brain amyloid β plaque deposits, reduce tau pathology, and reverse associated memory deficits. These findings indicate CHF-5074 acts simultaneously on several important therapeutic targets, and this neuroprotective multi-target approach may translate into preventing the memory loss that is the hallmark of Alzheimer’s disease.

Belnacasan (VX-765), and its active metabolite VRT- 043198, is a novel and irreversible IL-converting enzyme/ caspase-1 inhibitor. VRT-043198 exhibits 100- to 10,000-fold selectivity against other caspase-3, -6 and -9. It exhibited potent inhibition against ICE/caspase-1 and caspase-4 with Ki of 0.8 nM and less than 0.6 nM, respectively. And VRT-043198 also inhibits IL-1β release from both PBMCs and whole blood with IC50 of 0.67 uM and 1.9 uM, respectively. Belnacasan inhibits the release of IL-1, IL-18 and IL-33. Belnacasan has shown to inhibit acute partial seizures in preclinical models and has shown activity in preclinical models of chronic partial epilepsy that do not respond to currently available compounds for epilepsy. In addition, it seems to reduce disease severity and the expression of inflammatory mediators in models of rheumatoid arthritis and skin inflammation. Belnacasan had been in phase II clinical trials by Vertex for the treatment of epilepsy. However, this study has been terminated later.