Taprenepag isopropyl (also known as PF-04217329) a prodrug of CP-544326 (active acid metabolite), a potent and selective EP(2) receptor agonist. Taprenepag isopropyl was studied in a clinical trials phase II involving patients with primary open angle glaucoma. According to Pfizer’s pipelines in May 2011, the study was discontinued.

Sibrafiban (G-7453) is the orally administered, nonpeptide, double-prodrug of Ro 44-3888 which is a selective glycoprotein IIb/IIIa receptor antagonist. Sibrafiban is a double prodrug that undergoes bioconversion to the inactive prodrug Ro 48-3656 and to the active IIb/IIIa antagonist, Ro 44-3888, after oral administration. Sibrafiban was undergoing clinical trials for secondary prevention of cardiac events in patients stabilised after acute coronary syndromes. Sibrafiban has been shown to have comparable efficacy to aspirin in preventing recurrent ischemic events in patients suffering from acute coronary syndromes. Sibrafiban was under development by Genentech and Hoffmann-La Roche, and in phase III trials as an antithrombotic. The development of sibrafiban was discontinued in 1999 following unfavorable Phase III efficacy data.

Nexeridine, a pethidine derivative, is an opioid analgesic.

FERTIRELIN is an analog of luteinizing hormone releasing factor. The drug has been used since 1981 in Japan to treat various types of reproductive failure in cattle.

Dirucotide (MBP 8298) is a synthetic myelin basic protein (MBP) peptide designed to decrease type 2 helper T cells (TH2)-mediated B-cell signalling of auto-reactive T-cells thereby reducing the production of specific antibodies that target endogenous MBP. MBP is the dominant site of attack in patients with multiple sclerosis and haplotype (HLA) DR2 or DR4. Dirucotide did not meet the primary endpoint of delaying disease progression, as measured by the Expanded Disability Status Scale (EDSS), during the two-year MAESTRO-01 Phase III trial in patients with secondary progressive multiple sclerosis (SPMS). In addition, there were no statistically significant differences between dirucotide and placebo on the secondary endpoints of the study. After disappointing trial results, development of the drug was ended in 2009.

Pargeverine (also known as a propinox) is an antispasmodic drug that was studied for the treatment of disorders of the gastrointestinal tract, the uterus, and the gallbladder. Pargeverine showed a dual mechanism of action, it binds to muscarinic and calcium receptors that can be related to its antispasmodic activity. The clinical trial has shown that pargeverine was an effective drug in the treatment of moderate to severe colic pain of biliary origin. In addition, its efficacy and tolerability were determined in patients with moderate-to-severe acute intestinal colic pain. As a result, no differences in blood pressure or heart rate were found among treatments. The incidence of mouth dryness was significantly more frequent with the 20 mg and 30 mg doses of propinox than with the placebo or the 10 mg dose. Information about the current development of this drug is not available.

Clomegestone (clomagestone) is an investigational steroidal progestogen. Clomegestone exhibits anti-estrogenic activity in estrone stimulated immature mice when administered orally at 100 ug.

Icometasone (CL09) is a synthetic glucocorticoid corticosteroid. It is a metabolite of Mometasone Furoate. The binding on human serum albumin was shown to be non saturable, suggesting that other proteins were involved in CL09 binding. This binding was demonstrated to be reversible. CL09 was extensively metabolized since no unchanged CL09 was recovered in bile or urine and at least nine metabolites have been detected. It was studied in Europe as an anti-asthmatic agent but investigation is discontinued.