Ezatiostat (TLK199) [γ-glutamyl-S-(benzyl)cysteinyl-R-phenyl glycine diethyl ester] is an inhibitor of Glutathione S-transferase P1–1 (GSTπ). The drug is a peptidomimetic of GSH (glutathione), esterified to enhance cellular uptake and designed to bind to the “G-site” of GSTP1–1. Independent of catalysis inhibition, TLK199 also disrupts the protein:protein interaction site(s) between GSTP1–1 and JNK1. Telik Inc was developing TLK-199 for the potential prevention of myelosuppression in blood diseases, namely myelodysplastic syndrome.

Varespladib (LY315920; A-001) is a potent and selective inhibitor of IIa, V, and X isoforms of human non-pancreatic secretory phospholipase A2 with nM IC50. The molecule acts as an anti-inflammatory agent by disrupting the first step of the arachidonic acid pathway of inflammation. Varespladib methyl is being developed by Anthera Pharmaceuticals Inc for the potential treatment of coronary artery disease, acute coronary syndrome and inflammation. Varespladib methyl is a prodrug that is rapidly metabolized to varespladib, and both compounds are able to potently inhibit the enzymes of the human secretory phospholipase groups. Phase II clinical trials of varespladib methyl in patients with coronary artery disease, rheumatoid arthritis, asthma and ulcerative colitis revealed that the drug was well tolerated. Varespladib methyl did not demonstrate a good efficacy profile in patients with rheumatoid arthritis, asthma and ulcerative colitis; whereas in patients with coronary artery disease, varespladib methyl consistently reduced LDL-cholesterol levels, (elevated LDL-cholesterol levels are a marker of increased cardiovascular risk). Varespladib methyl could represent a novel therapy for the treatment of cardiovascular disease, although the efficacy, safety profile and advantages of this drug compared with existing therapeutic options would need to be established in upcoming phase III trials.

Tecalcet (also known as KRN-568; NPS-R-568; R-568), is an oral calcium channel agonist potentially for the treatment of hyperparathyroidism. Calcimimetics, such as Tecalcet, are agonists and activate the calcium channel in a non-competitive fashion. Tecalcet does not compete directly with calcium that activates the receptor through binding in the extracellular domain of these receptors, but rather, calcimimetics such as Tecalcet, bind allosterically in the seven transmembranes to ‘sensitize’ the receptor to extracellular calcium. Tecalcet acts as an agonist of the calcium receptors of the parathyroid cells, causing a decrease in PTH release. Tecalcet also acts on the parafollicular cells (C-cells) of the thyroid gland, resulting in an increase in calcitonin release. These effects ultimately lead to a decrease in plasma calcium concentrations. Studies in rats have shown that oral administration of R-568 at doses ranging from 3 to 100 mg/kg caused a rapid (<30 minutes) decrease in plasma PTH concentrations and an increase in calcitonin concentrations, accompanied by a dose-dependent decrease in calcium concentrations. Tecalcet had been in phase II clinical trials by for the treatment of hyperparathyroidism, postmenopausal osteoporosis and rheumatic disorders in Japan and US. Development of Tecalcet has been discontinued.

Fandosentan (CI 1034 or PD 180988) is an endothelin A receptor antagonist. It inhibits pulmonary vasoconstriction. Fandosentan was being developed for the treatment of chronic obstructive pulmonary disease and pulmonary hypertension.

Etisazole was studied as a veterinary fungicide, possessed skin sensitizing properties in man. Information about the current use of this compound is not available.

Dimetipirium is a spasmolytic, antineoplastic and anticholinergic agent.

Gantofiban (or EMD 122 347) is an oral double prodrug of the drug, EMD 132338 and is GPIIb/IIIa antagonist. The drug participated in phase II clinical trials in Japan in patients with thrombosis. However, in May 2004, Yamanouchi, the developing company, announced that the study was discontinued. Besides gantofiban was involved in phase II trials, like a treatment option in patients with the acute coronary syndrome. However, further information is not available.

Etoformin is an antidiabetic drug. It decreases gluconeogenesis and increases peripheral utilization of glucose.

Binospirone (MDL-73,005-EF) acts as a potent, highly selective 5-HT1A ligand: as an antagonist at postsynaptic 5-HT1A receptors and also acts as a highly efficacious partial agonist at somatodendritic autoreceptors. Experiments on rodents have shown, that it also possesses anxiolytic properties.