Zaurategrast (CDP323) is an ethyl ester prodrug of CT7758, a potent carboxylic acid antagonist of integrin alpha4-beta1 (α4β1) or very late antigen 4 (VLA4). CDP323 was under development with UCB and Biogen Idec for the treatment of multiple sclerosis. Its development was discontinued in 2009 based on inadequate interim efficacy data in a phase II clinical trial.

Sparfosate (PALA) is a stable transition state analogue for an aspartate transcarbamylase- cartalyzed reaction with antineoplastic activity. PALA is a potent inhibitor of aspartate transcarbamylase (Ki about 10(-8) M for ACTases of various origins), which in whole cells blocks the de novo synthesis of pyrimidines. Thus PALA inhibits de novo pyrimidine biosynthesis and increases the extent to which fluorouracil metabolites are incorporated into RNA. In vivo, low doses of PALA inhibit whole body pyrimidine synthesis. While this action is cytotoxic in vitro, extensive human testing demonstrates that PALA alone is devoid of selective antitumor activity. Interest in the therapeutic action of PALA derives from the demonstration that its action potentiates the cytotoxicity of several cytotoxic drugs, notably 5-fluorouracil (5-FU). Development of Sparfosate for cancer and Hepatitis B treatment is assumed to have been discontinued.

Modithromycin (EDP-420, EP-013420, S-013420) is 6-11-bicyclic erythromycin derivative patented by Enanta Pharmaceuticals, Inc as an antibacterial agent. In preclinical studies, Modithromycin exhibited high levels of in vitro activities against N. gonorrhea, including isolates resistant to azithromycin, cefixime, ceftriaxone, spectinomycin, ampicillin, tetracycline, and ciprofloxacin. Modithromycin also has the good in vivo efficacy against S. pneumoniae and H. influenzae, which might be due to its lasting intracellular activity. In healthy adults, clinical trials Modithromycin shows long half-life and its high systemic exposure. Modithromycin was well tolerated, with no serious or severe adverse events reported, and no subject was discontinued from the study due to an adverse event. In 2005 Modithromycin was studied in phase II clinical trials but no further development reports were published.

Fluorescein Lisicol (NRL972) is a fluorescent-labelled bile acid analog that is used as an investigational marker for liver function, specifically hepatic biliary transporter function. Fluorescein Lisicol has been used in trials investigating the pharmacokinetics of hepatic cirrhosis, viral hepatitis, non-alcoholic steatohepatitis and non-alcoholic fatty liver disease.

Methylenedioxymethamphetamine (or 3,4-methylenedioxymethamphetamine (MDMA)), a synthetic, psychoactive drug also known as ecstasy that was used as a recreational drug. This drug acts as both a stimulant and psychedelic and exerts its effects in the brain on neurons that use the chemicals serotonin, dopamine and norepinephrine to communicate with other neurons. In spite of the presence of this compound in the List of control and forbidden compounds, it was studied in psychotherapy for patients with chronic, treatment-resistant posttraumatic stress disorder. Initial results showed efficacy for the treatment approach, although further studies are needed.

Livoletide (AZP-531) is an analog of unacylated ghrelin, a naturally occurring hormone that is thought to counteract the effects of acylated ghrelin. The drug was designed to improve glycaemic control and reduce weight. Livoletide participated in pivotal phase 2b/3 clinical study for the treatment of Prader-Willi syndrome. In addition, the drug was studied in patients with type 2 diabetes mellitus (T2D). Its pharmacokinetic profile, suitable for once daily dosing, and metabolic effects support further clinical development for T2D.