UCB35625 is a potential inhibitor of chemokine/eosinophil interactions. UCB35625 is a trans-isomer of a compound J113863, which was originally identified by scientists at Banyu Pharmaceutical Company as a candidate small molecule chemokine receptor antagonist. UCB35625 initially identified as CCR1 and CCR3 antagonists also bind to CCR2 and CCR5 and act as full agonist, partial agonist or antagonist according to the nature of the receptor and the signaling pathway investigated. UCB35625 shows promise as a lead compound for the design of future therapeutics, which may be of use in the treatment of allergic inflammatory diseases such as asthma and also the blockade of viral entry by HIV strains that utilize CCR3.

J 113863 is a potent and high selective CKR-1 (CCR1) and CKR-3 (CCR3) chemokine receptor antagonist, which is also behaved as a full agonist of CCR2 and as a very partial agonist of CCR5. This compound was investigated for the treatment of multiple sclerosis and rheumatoid arthritis, but the status of these studies are not known.

GW-803430 is centrally active and selective antagonist of melanin-concentrating hormone receptor (MCHR) 1. GlaxoSmithKline was developing orally active, potent and selective GW-803430 for the treatment of obesity. GW803430 produces robust antiobesity and antidepressant-like effects in rodents.

A-987306 is a new histamine H(4) antagonist. A-987306 is potent in H(4) receptor binding assays (rat H(4), K(i) = 3.4 nM, human H(4) K(i) = 5.8 nM) and demonstrated potent functional antagonism in vitro at human, rat, and mouse H(4) receptors in cell-based FLIPR assays. A-987306 also demonstrated H(4) antagonism in vivo in mice, blocking H(4)-agonist induced scratch responses, and showed anti-inflammatory activity in mice in a peritonitis model. Most interesting was the high potency and efficacy of this compound in blocking pain responses, where it showed an ED(50) of 42 umol/kg (ip) in a rat post-carrageenan thermal hyperalgesia model of inflammatory pain. A-987306 inhibited the scratching response (IC50 = 0.4 umoles/kg, i.p.) with (85%) inhibition seen at 30 umoles/kg, i.p. A-987306 is a potent and selective H4R antagonist with robust antipruritic activity and is a useful tool for further exploration of the role of H4R receptors in vivo.

A-943931 is a potent and selective H4R antagonist with high affinity at both human (Kis = 4.6 nM) and rat (Kis = 3.8 nM) receptors. A-943931 competitively and potently antagonizes rat H4R agonist-mediated responses in [35S]GTPγS binding assays (Kbs = 28 nM) and intracellular calcium mobilization at rat and human receptors (Kbs from 5-10 nM). When tested in vivo in a mouse model of clobenpropit (10 nM, i.d.) induced scratching, A-943931 inhibited the scratching response (IC50 = 26 umoles/kg, i.p.) with significant inhibition (69%) at the highest tested dose (30 umoles/kg, i.p.). A-943931 is a potent and selective H4R antagonist with robust antipruritic activity and is a useful tool for further exploration of the role of H4R receptors in vivo.

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).