LAPAQUISTAT is a squalene synthase inhibitor. It was shown to lower cholesterol levels in several animal models. It was investigated for the treatment of diabetes and hypercholesterolemia, however, its development was discontinued.

LAUROLINIUM, a quaternary ammonium compound, is a cationic antimicrobial agent. It has a broad spectrum of activity against Gram‐positive and Gram‐negative bacteria, fungi, and protozoan Trichomonas vaginalis. It is suitable for use in the treatment of local infections, for the sterilization of skin areas and for general antiseptic purposes.

Dexecadotril is powerful and selective inhibitor of neprilysin. It is anti-hypotensive agent. Dexecadotril was found to possess chemoprotective activity. It might be biologically active against multiple myeloma. It was under clinical evaluation as an intestinal antisecretatory agent.

Davalintide (AC-2307) is a second-generation mimetic of a pancreatic peptide hormone amylin, developed by Amylin Pharmaceuticals. In preclinical models, davalintide possessed enhanced pharmacological properties and was able to reduce food intake. Safety, tolerability, and effect on body weight of subcutaneous davalintide were investigated in obese or overweight subjects. The results of the clinical trial were not reported, but Amylin decided to discontinue davalintide in 2010.

Inocoterone acetate (USAN) (also known as RU-38882, RU-882) is the acetate ester of inocoterone a steroid-like nonsteroidal antiandrogen (NSAA) that was developed for topical administration to treat acne but was never marketed. Inocoterone acetate is actually not a silent antagonist of the androgen receptor but rather a weak partial agonist, similarly to steroidal antiandrogens like cyproterone acetate. In this double-blind study of 126 male subjects with acne, a topical solution of the antiandrogen inocoterone produced a modest but statistically significant reduction in the number of inflammatory acne lesions.

Vadimezan (5,6-dimethyl(xanthenone-4-acetic acid), ASA404, DMXAA) is a fused tricyclic analogue of flavone acetic acid with potential antineoplastic activity. In pre-clinical mouse tumour models it was demonstrated that administration of Vadimezan rapidly leads to disruption of the existing vasculature in the tumour and consequent haemorrhagic necrosis of the tumour. This was consistent with the finding that a single dose of Vadimezan induced a prolonged reduction in the growth of xenografted tumours in animal models. The ability to disrupt the vasculature in these pre-clinical models has been attributed to a rapid induction of cytokines, particularly TNFα (tumour necrosis factor α), serotonin and nitric oxide, resulting in hemorrhagic necrosis and a decrease in angiogenesis. Despite the fact that the molecular targets for the drug remained unknown, the promising pre-clinical results led to Vadimezan being selected for clinical development. Results of Phase I trials showed some restriction of tumour blood flow within 24 h of treatment, although this was not as dramatic as seen in pre-clinical models. Unlike the animal models, there was also very little evidence for the rapid death of blood vessels or for increases in TNFα levels in human tumors. No difference in antitumour activity, cytokine induction or toxicity was observed between two parallel Phase I trials, one dosed weekly and the other dosed every 3 weeks. Therefore the drug proceeded to Phase II clinical trials, dosed every 21 days in combination with chemotherapeutic agents. These trials indicated the drug had small benefits in the treatment of non-small-cell lung cancer and prostate cancer. However, a subsequent Phase III clinical trial was not able to reproduce this response and clinical development was halted.

Thiorphan is the first potent synthetic inhibitor of enkephalinase. Thiorphan displays antinociceptive activity after systemic administration. Thiorphan also inhibits to a lesser extent the widely distributed angiotensin-converting enzyme, a carboxydipeptidase implicated in blood pressure regulation. Thiorphan failed to potentiate allergen-induced airway responses in asthma. Thiorphan significantly reduced the castor oil-induced diarrhea in rats when administered intravenously but not when administered intracerebroventricularly. Racecadotril, via its active metabolite thiorphan, was consistently effective in animal models and patients with various forms of acute diarrhea by inhibiting pathologic (but not basal) secretion from the gut without changing gastro-intestinal transit time or motility.

Amibegron (SR 58611A or SR 58611) is a highly selective agonist for atypical beta3-adrenoceptors. It stimulates neuronal activity in a specific area of the prefrontal cortex and also inhibits intestinal motility. Amibegron was in phase III trials worldwide for the treatment of depression and generalised anxiety disorder but development of the product was discontinued in 2008. Amibegron has been tested for its potential as a treatment for irritable bowel syndrome.