INCB3284 or INCB-3284 Incyte’s internally developed, oral human CCR2 antagonist for the treatment of chronic inflammations. It is in Phase IIa trial of patients with rheumatoid arthritis (RA).

SB-743921 is a synthetic small molecule with potential antineoplastic properties. SB-743921 selectively inhibits the ATP-binding domain of the kinesin spindle protein (KSP), an important protein involved in the early stages of mitosis that is expressed in proliferating cells. Inhibition of KSP results in inhibition of mitotic spindle assembly and interrupts cell division, thereby causing cell cycle arrest and induction of apoptosis. SB-743921 has greater than 40,000 fold selectivity for KSP over other kinesins. SB-743921 has demonstrated promising anti-cancer activity in a variety of in vivo and in vitro human cancer models in preclinical studies. Furthermore, anti-cancer effect has been demonstrated in taxane-refractory malignancies with SB-743921. Toxicity studies demonstrated predictable neutropenias and gastrointestinal toxicities without clear evidence of neurotoxicity. The recommended phase II dose for SB-743921 as a 1-h infusion every 21 days is 4 mg/m2.

PHA-543613 was discovered by Pfizer and has been under development primarily as a potential treatment of schizophrenia. PHA-543613 acts as an agonist to the Neuronal acetylcholine receptor protein alpha-7 subunit. A single human trial was conducted in healthy human volunteers, but the compound has been studied extensively in rat models for schizophrenia as well as Parkinson's disease and Alzheimer's disease.

Idazoxan is an alpha2 receptor antagonist which also shows activity at imidazoline I1 and I2 receptors and modulates the release of dopamine. Idazoxan was in phase II development in the US. Later the development of idazoxan for schizophrenia was discontinued. It was also in clinical trials for cognition disorders in United Kingdom, and was also discontinued. Idazoxan is used in scientific research as a tool for the study of alpha 2-adrenoceptors. Idazoxan`s diastereoisomers possess different relative selectivity for alpha2- pre- and postsynaptic receptors: (+)-idazoxan was 7-8 times more potent than (-)-idazoxan in inhibiting p-[3H]aminoclonidine binding, and 40 times more active in antagonizing clonidine at presynaptic level, indicating a better selectivity for alpha2-presynaptic sites. The pre- and postsynaptic alpha2-adrenoceptors have a different affinity for the two enantiomers of idazoxan. Although the stereoisomers are closely related structurally, (+)-idazoxan possesses a stronger affinity for presynaptic sites. This stereoselectivity was less evident for postsynaptic sites. In rats and dogs, both enantiomers antagonized the sympathoinhibitory effects of clonidine. In rats, (+)- idazoxan was 4-7 times more potent than (-)- idazoxan and 3-8 times more than (-)- idazoxan in dogs. A same order of potency was observed against the sedative effects of clonidine and azepexole in chicks, (+)- idazoxan being 8 times more potent than (-)- idazoxan. Although (+)- idazoxan was more potent than (-) idazoxan, binding studies revealed (-)- idazoxan to be more selective than (+)- idazoxan at central sites. It is concluded that (+)- idazoxan antagonizes both alpha-1 and alpha-2 adrenoceptors and (-)- idazoxan is selective for alpha-2 adrenoceptors. In the pithed rat, only (-)- idazoxan possesses both alpha-1 and alpha-2 agonistic effects.

Levovirin is a guanosine nucleoside analog and the L-enantiomer of ribavirin. It is an investigational drug for the treatment of hepatitis C virus-mediated diseases. Levovirin has a similar immunomodulatory potency to ribavirin in vitro without accumulating in red blood cells or causing hemolytic anemia, a known side effect of ribavirin. Levovirin has been shown to stimulate host immune responses (enhanced Th1 and reduced Th2 cytokine expression). Significantly improved oral absorption of levovirin was achieved following administration of a valine ester prodrug of levovirin R1518. Levovirin was found more potent to inhibit Tick-borne encephalitis virus (TBEV) on the basis of robust binding affinity between protein-drug interactions. This finding may help to understand the nature of helicase and development of specific anti-TBEV therapies.

JTC 801 was developed by Japan Tobacco as a novel opioid receptor-like1 (ORL(1)) receptor antagonist. It was found, that JTC-801 completely antagonized the suppression of nociceptin on the forskolin-induced accumulation of cyclic AMP using ORL(1) receptor expressing HeLa cells in vitro. JTC 801 produced analgesic effects and was studied in phase II of a clinical trial for the treatment of neuropathic, cancer and postoperative pain. Nevertheless, that studies were discontinued.

SB-271046 is one of the first selective 5-HT6 receptor antagonists to be discovered. SB-271046 is a potent, selective and orally active 5-HT6 receptor antagonist with a pKi value of 8.9. This compound provides a useful tool for further elucidating the physiological function of 5-HT6 receptors in vivo. SB-271046 was found to increase levels of the excitatory amino acid neurotransmitters glutamate and aspartate, as well as dopamine and noradrenaline in the frontal cortex and hippocampus of rats, and 5-HT6 antagonists have been shown to produce nootropic effects in a variety of animal studies. Suggested applications of SB-271046 included treatment of schizophrenia and other psychiatric disorders. A phase I clinical development of SB-271046 by GlaxoSmithKline (GSK) was discontinued due to a poor BBB permeability.

SB-743921 is a synthetic small molecule with potential antineoplastic properties. SB-743921 selectively inhibits the ATP-binding domain of the kinesin spindle protein (KSP), an important protein involved in the early stages of mitosis that is expressed in proliferating cells. Inhibition of KSP results in inhibition of mitotic spindle assembly and interrupts cell division, thereby causing cell cycle arrest and induction of apoptosis. SB-743921 has greater than 40,000 fold selectivity for KSP over other kinesins. SB-743921 has demonstrated promising anti-cancer activity in a variety of in vivo and in vitro human cancer models in preclinical studies. Furthermore, anti-cancer effect has been demonstrated in taxane-refractory malignancies with SB-743921. Toxicity studies demonstrated predictable neutropenias and gastrointestinal toxicities without clear evidence of neurotoxicity. The recommended phase II dose for SB-743921 as a 1-h infusion every 21 days is 4 mg/m2.

PD-153035 is a potent and selective ATP-competitive inhibitor of the epidermal growth factor receptor tyrosine kinase EGFR. PD 153035 shows a potent and selective inhibitory effect on tyrosine phosphorylation induced by EGF in Swiss 3T3 fibroblast and A-431 human epidermoid carcinoma cells. PD153035 shows dose-dependent growth inhibitory effects in cultures of EGF receptor-overexpressing human cancer cell lines (A431, Difi, DU145, MDA-MB-468, and ME180) and in nasopharyngeal carcinoma (NPC) cell lines (NPC-TW01, NPC-TW04, and HONE1). Pretreatment of EGFR inhibitors by 24 hours significantly enhances the cytotoxic effect of doxorubicin, paclitaxel, cisplatin, and 5-fluorouracil in NPCTW04 cells. PD153035 abolishes COX-2 expression induced by the PAR(2)-activating peptide 2-furoyl-LIGRLO-NH(2) (2fLI) in Caco-2 colon cancer cells. In A431 human epidermoid tumors grown as xenografts in immunodeficient nude mice, PD153035 at 80 mg/kg i.p. inhibit EGF receptor tyrosine kinase activity. PD153035 improves glucose tolerance, insulin sensitivity, and signaling and reduces subclinical inflammation in HFD-fed mice.

Piperidine is a normal constituent in mammalian brain. It was shown to affect synaptic mechanism in the CNS, and influence neural mechanisms governing regulation of emotional behavior, sleeping, and extrapyramidal function. In addition, there are enzyme systems within the brain that synthesize and metabolize piperidine, and uptake and storage mechanisms for piperidine are found in the nerve endings. Piperidine, which proved to be a highly effective “antipsychotomimetic” agent in rats, has been reported to bring about substantial improvement in a variety of schizophrenic patients.