1‐α‐D‐(5‐Fluoro‐5‐deoxyarabinofuranosyl)‐2‐nitroimidazole (fluoroazomycin arabinoside, FAZA) is a putative PET imaging agent when labelled with 18F. Fluoroazomycin arabinoside is essential in the generation of fluorine F 18-fluoroazomycin arabinoside (18F-FAZA), which is a radiofluorinated 2-nitroimidazole derivative with hypoxia (low oxygen)-specific tracer activity. 18F-FAZA is reduced under hypoxic conditions, forming highly reactive intermediates. In its reduced form, 18F-FAZA covalently binds to macromolecules, thereby accumulating in hypoxic cells (e.g. malignant tumors) and allowing radioisotopic imaging of these particular cells with positron emission tomography (PET).

GW-870086 (now known as GSK 870086) was developed by GlaxoSmithKline as a glucocorticoid receptor agonist. Repeat inhaled doses of GW-870086 was studied in phase II clinical trial in patients with asthma. In addition, phase II clinical trial was investigated to determine the efficacy of GW-870086 ream formulation in subjects with moderate to severe atopic dermatitis. However, the development of this drug appears to have been discontinued.

11C-NOP-1A is a new radioligand for thenociceptin/orphanin FQ peptide (NOP) receptor, with high affinity (Ki, 0.15 nM) and appropriate lipophilicity (measured logD, 3.4) for PET brain imaging. 11C-NOP-1A is the the first successful radioligand to image NOP receptors in rat and monkey brain. 11C-NOP-1A is a selective antagonist at the NOP receptor and has high affinity and appropriate lipophilicity for blood–brain barrier permeability. 11C-NOP-1A imaging in rhesus monkeys showed high brain uptake and a large receptor-specific signal and could be quantified with the gold standard method of compartmental modeling. In humans 1C-NOP-1A reliably quantified NOP receptors in human brain both in large brain regions and at a voxelwise level using parametric imaging. The radiation absorbed dose in humans was similar to that observed with other 11C-labeled ligands and would allow multiple scans of a single subject. Thus, 11C-NOP-1A is a promising radioligand for reliably quantifying NOP receptors in human brain.

Fluoroazomycin Arabinoside F-18 (18F-FAZA) is a radiofluorinated 2-nitroimidazole derivative with hypoxia (low oxygen)-specific tracer activity. 18F-FAZA is reduced under hypoxic conditions, forming highly reactive intermediates. In its reduced form, 18F-FAZA covalently binds to macromolecules, thereby accumulating in hypoxic cells (e.g. malignant tumors) and allowing radioisotopic imaging of these particular cells with positron emission tomography (PET). (18)F-FAZA shows superior biokinetics and is, thus, a promising PET tracer for the visualization of tumor hypoxia. Clinical evaluation of 18F-FAZA is currently ongoing, and early results have been reported for head and neck, lung, prostate, and rectal cancers.

D-Methyldopa is an inactive isomer of methyldopa. It is known, that only L-isomer has the ability to inhibit dopa decarboxylase and possesses the antihypertensive activity in man. Moreover, about twice the dose of the racemate (DL-form of methyldopa) is required for the equal antihypertensive effect.

(R)-Mequitazine or V0162 (10-[(3R)-1-azabicyclo[2.2.2]oct-3-ylmethyl]-10H-phenothiazine) is an anticholinergic enantiomer of mequitazine, an existing oral racemic antihistamine commercialized for over 30 years. (R)-Mequitazine was found to be an antagonist at muscarinic acetylcholine receptors behaving as an inverse agonist. (R)-Mequitazine was investigated in clinical trials for the treatment of chronic obstructive pulmonary disease, asthma and urinary incontinence.

4‐Chlorokynurenine (AV-101) is a neuropharmaceutical drug candidate in development for the treatment of major depressive disorder. Pharmacology studies conducted in rodent models have demonstrated AV-101’s antihyperalgesic activity in models of facilitated pain processing was seen at serum concentrations ranging from 150–300 M. In addition, AV-101 has been shown to be neuroprotective activity against an intrahippocampal injection of quinolinic acid, reductions in seizures, and antidepressive activity. An oral prodrug, AV-101, which, in the brain, is converted into one of the most potent and selective GlyB site antagonists of the NMDAR, has been demonstrated to be active in animal models of neuropathic pain. The two Phase 1 studies were designed to assess the safety and pharmacokinetics of AV-101, over a wide dose range, after daily dosing for 14-days. AV-101 has excellent safety and PK characteristics providing support for advancing AV-101 into Phase 2 studies in neuropathic pain.