Cridanimod (Virexxa) is a small-molecule immunomodulator and interferon inducer, which, in preliminary studies, has been shown to increase progesterone receptor expression in endometrial tissue. Restoration of progesterone receptor expression may re-sensitize endometrial tumor tissue to progestin therapy in previously unresponsive tumors. Cridanimod was originally developed by Polysan and Pharmsynthez and licensed to Xenetic Biosciences. Virexxa is currently being studied in an ongoing Phase 2 multi-national study in conjunction with progestin therapy for the treatment of endometrial cancer in women with the recurrent or persistent disease who have failed progestin monotherapy.

Sitaxentan (TBC11251, trade name Thelin) is a potent and selective Endothelin A receptor antagonist. Sitaxentan was under development by Encysive Pharmaceuticals (now Pfizer) for use in the treatment of pulmonary hypertension, congestive heart failure and asthma. It was launched in the major markets of the European Union (EU) under name Thelin for the treatment of pulmonary arterial hypertension. In December 2010, Pfizer discontinued clinical trials of sitaxentan worldwide and initiated voluntary product withdrawal from markets where it is approved due to life-threatening idiosyncratic risk of liver injury.

Avorelin is a superagonist of natural luteinizing-hormone-releasing-hormone. Avorelin has been formulated in high molecular weight polylactic glycolic acid to afford protracted and continuous release of the peptide from subcutaneous implants. Avorelin has been in phase II clinical trials by Mediolanum for the treatment of prostate cancer, breast cancer and endometriosis. However, this research has been discontinued. Adverse events mainly related to androgen suppression (hot flushes, decreased libido and impotence) or the nature of the disease (skeletal pain).

Ritipenem (FCE 22101), a penem antibiotic, penicillin binding protein inhibitor, is potent against both gram-positive and -negative bacteria, and its acetoxymethyl ester (FCE 22891; ritipenem-acoxil) is orally available. Ritipenem is manufactured by Tanabe Seiyaku in the ritipenem acoxil prodrug form, which can be taken orally. It is not FDA approved in the United States.

Lenapenem is an anti-bacterial agent that was tested in late 90's in phase II clinical trials against bacterial infections. Lenapenem was shown to be active against both Gram-positive and Gram-negative bacteria and exerted its therapeutic effect by inhibiting penicillin binding proteins. The development of the drug was terminated due to the safety reason.

Cyclocytidine HCl (also known as Ancitabine) is the prodrug of cytarabine, which is structurally similar to human deoxycytidine to be incorporated into human DNA and then kills the cell. Cyclocytidine was introduced as an antineoplastic agent for the treatment of lymphatic leukemia, sinus acceleration and an increase in systemic blood pressure. Cyclocytidine in combination with amsacrine were effective retrieval therapy for pediatric patients with acute nonlymphoblastic leukemia who were in relapse or unresponsive to frontline therapy.

Velnacrine (9-amino-1,2,3,4-tetrahydroacridin-1-ol) is an inhibitor of acetylcholinesterase. It was studied for the treatment of Alzheimer's disease however development was discontinued. There has been no research into the use of velnacrine as a cognitive enhancer in the treatment of Alzheimer's disease since 1994. The FDA peripheral and CNS drug advisory board voted unanimously against recommending approval. This review shows the toxic nature of velnacrine, and provides no evidence of efficacy.

Cibenzoline is a class I sodium channel blocker antiarrhythmic drug available in a limited number of countries. Cibenzoline also has moderate calcium channel blocking (class IV) effects and prolongs the action potential duration through its potassium channel blocking (class III) effect. It is used for the treatment of supraventricular and ventricular arrhythmias, and in obstructive hypertrophic cardiomyopathy.

Talipexole is a D2 receptor agonist which was marketed in June 1996 in Japan for the treatment of Parkinson's disease. Clinical trials with talipexole in patients with Parkinson's disease demonstrated statistically significant improvements from baseline for parkinsonian symptoms including akinesia, rigidity, tremor and gait disturbances.

Dopexamine hydrochloride is a synthetic catecholamine, structurally related to dopamine, with marked intrinsic agonist activity at beta 2-adrenoceptors, lesser agonist activity at dopamine DA1- and DA2-receptors and beta 1-adrenoceptors, and an inhibitory action on the neuronal catecholamine uptake mechanism. The drug is administered by intravenous infusion, and is characterized by a rapid onset and short duration of action. Dopexamine is being tested as a treatment for heart failure and sepsis.