Piriprost (U-60, 257) is a structural analog of prostaglandin I2 (PGI2) with low IP receptor-mediated activity. It inhibits 5-LO (5-lipoxygenase). Piriprost inhibits the release of histamine and leukotrienes, implicating its role in inflammation and allergic responses. However, it was shown, that piriprost did not influence the airway responses after allergen in asthma. Nevertheless, even more, the drug was irritant to the respiratory tract than was placebo.

Omidoline, an antiparkinsonian agent that has never been marketed. Information about the current use of this drug is not available.

16alpha-Bromoepiandrosterone (HE2000) is a synthetic steroid that limits non-productive inflammation, enhances protective immunity and improves survival in clinical studies of patients with human immunodeficiency virus (HIV), malaria and tuberculosis infections. HE 2000 had also shown activity in vitro against cytomegalovirus, polio, hepatitis B and C and influenza virus. 16alpha-Bromoepiandrosterone inhibits glucose-6-phosphate dehydrogenase (G6PD) and cell proliferation. HE 2000 was in phase II development for the Hepatitis B in Malaysia and Singapore, but it was suspended.

Eritoran (E-5564) is a synthetic lipid A analog that has been designed to antagonize the effects of lipopolysaccharide (LPS) and has been found to do this by interacting with Toll-like receptor 4, the cell surface receptor for LPS. Preclinical in vitro and in vivo studies of eritoran tetrasodium indicate it can limit excessive inflammatory mediator release associated with LPS and improve survival in sepsis models. Clinically, eritoran was being investigated for the treatment of severe sepsis, septic shock, and other endotoxin-mediated indications. Eritoran development has been discontinued.

Taltobulin, also known as HTI-286 and SPA-110, is a fully synthetic analog of the natural tripeptide hemiasterlin, inhibits tubulin polymerization and circumvents transport-based resistance to taxanes. Taltobulin was a potent inhibitor of proliferation (mean IC50 = 4 nm in 18 human tumor cell lines) and had substantially less interaction with multidrug resistance protein (P-glycoprotein) than currently used antimicrotubule agents, including paclitaxel, docetaxel, vinorelbine, or vinblastine. Taltobulin showed strong antitumor activity both in androgen-dependent and androgen- independent tumors and may be a promising agent in second- line treatment strategies for patients suffering from docetaxel- refractory prostate cancer.

Atrasentan (ABT-627, A-127722) is a selective endothelin A receptor antagonist. Atrasentan is being developed by AbbVie as an oral treatment for diabetic nephropathies.Abbott Laboratories was conducting clinical development of atrasentan for the treatment of certain cancers, including phase II trials for prostate cancer. However, no recent development has been reported for cancer indications and development is presumed to be discontinued.

2-Methoxyestradiol (2ME2) is a natural metabolite of endogenous estrogen hormone 17β-estradiol in human and devoid of estrogenic activity. It is a drug that prevents the formation of new blood vessels that tumors need in order to grow (angiogenesis). It has undergone Phase 1 clinical trials against breast cancers. Preclinical models also suggest that 2ME2 could also be effective against inflammatory diseases such as rheumatoid arthritis. 2-Methoxyestradiol is an angiogenesis inhibitor, and has been shown to attack both tumor cells and their blood supply in preclinical testing. Presently, it is an investigational drug under various phases of clinical trials alone or in combination therapy. Its anticancer activity has been attributed to its antitubulin, antiangiogenic, pro-apoptotic and ROS induction properties. 2-Methoxyestradiol shows strong cytotoxic effect on estrogen dependent and independent cancerous cells, which is mainly due to disruption of microtubule process and p53 induced apoptosis through caspase, reactive oxygen species (ROS), superoxide dismutase (SOD) and nitric oxide synthase. 2-Methoxyestradiol inhibits tubulin polymerisation by binding to colchicine binding site of the tubulin and arrests cell cycle at G2/M-phase.

Mesabolone is a synthetic anabolic androgen.

Elarofiban is a novel nonpeptide glycoprotein IIb/IIIa (GPIIb/IIIa) antagonist. It inhibits thrombin-induced platelet aggregation in human gel-filtered platelets and platelet aggregation in human platelet-rich plasma (PRP) in response to collagen, arachidonic acid, ADP, and SFLLRN-NH(2). Elarofiban had adequate oral pharmacokinetics in dogs and excellent oral pharmacodynamics. Elarofiban has been in phase II clinical trials for the treatment of myocardial infarction and thrombosis. However, this research has been discontinued.