Talibegron (ZD2079) is a β3 adrenoceptor agonist and insulin sensitiser. It was developed as a potential treatment for obesity and non-insulin-dependent diabetes mellitus. Talibegron hydrochloride had been in phase II clinical trials by AstraZeneca for the treatment of type 2 diabetes and obesity. However, this research has been discontinued.

Tesmilifene is a small-molecule antineoplastic drug and chemopotentiator that was under development by YM BioSciences for the treatment of breast cancer. Tesmilifene was developed as a selective ligand of the antiestrogen binding sites without estrogen receptor affinity. Tesmilifene potentiates the cytotoxicity of a variety of chemotherapy drugs in vitro and in vivo. Tesmilifene in combination with doxorubicin provides an unexpected and very large survival advantage over doxorubicin alone in a randomized trial in phase III clinical trial in advanced breast cancer. Unfortunately, Tesmilifene application associated with high rate disease and treatment-related adverse events and poor quality of life. Based on these results further development of Tesmilifene was discontinued

Icopezil (previously known as CP-118,954) was developed as a selective acetylcholinesterase inhibitor for the treatment of cognitive disorders. Phase II trials of icopezil were underway in Japan and in the USA for the treatment of patients with Alzheimer's disease. However, Pfizer has discontinued these studies.

Dactolisib is a dual inhibitor of phosphatidylinositol 3-kinase (P13K) and the downstream mammalian target of rapamycin (mTOR) by binding to the ATP-binding cleft of these enzymes (inhibitor of PI3K/Akt/mTOR cascade). It is being investigated as a possible anti-cancer cancer agent and drug against Influenza virus infections. Frequently reported adverse events included nausea, vomiting, diarrhoea, fatigue/asthenia, anaemia, and anorexia.

Forodesine hydrochloride is the salt of the synthetic high-affinity transition-state analog forodesine (BCX-1777, immucillin-H), a substrate designed to mimic the properties or the geometry of the transition state of reaction. It is an anticancer drug that has been developed for the treatment of different hematologic malignancies. In December 2006, orphan designation (EU/3/06/421) was granted by the European Commission to Napp Pharmaceuticals Research Limited, United Kingdom, for forodesine hydrochloride for the treatment of acute lymphoblastic leukemia. Forodesine hydrochloride has been evaluated in Phase I/Phase II clinical trials for several cancer types including chronic lymphocytic leukemia (CLL), B-Cell acute lymphoblastic leukemia and refractory cutaneous T-cell lymphoma (CTCL). Forodesine is a potent purine nucleoside phosphorylase (PNP) inhibitor that acts by elevating plasma 2'-deoxyguanosine (dGuo) and intracellular deoxyguanosine triphosphate, which in turn affects deoxynucleotide-triphosphate pools and induces cell death by apoptosis. Forodesine in the presence of dGuo inhibited the proliferation of CEM-SS (T-acute lymphoblastic leukemia) cells with an IC50 of 0.015 uM. This inhibition by forodesine and dGuo was accompanied by a 154-fold and 8-fold elevation of endogenous dGuo triphosphate (dGTP) and deoxyadenosine triphosphate (dATP) pools, respectively. Cytotoxic activity of forodesine in the presence of dGuo was selective to T lymphocytes. It is a 10- to 100-fold more potent inhibitor of human lymphocyte proliferation than other known PNP inhibitors such as PD141955 and BCX-34.8

Atiprosin (AY-28,228), an octahydro-pyrazino-pyrido-indole drug, possesses the alpha-adrenoceptor antagonist activity and exerts antihypertensive effects. Atiprosin has never been marketed

Ondelopran (also known as LY2196044) was developed as orally available opioid receptor antagonist for the treatment of alcoholism. This drug completed clinical trials phase III where was assess its efficacy and safety in the treatment of alcohol dependence in adult outpatients.

Org 25935 (SCH 900435) is a synthetic drug developed by Organon International, which acts as a selective inhibitor of the glycine transporter GlyT-1. In human trial for prevention of relapse in alcohol-dependent patients in Org 25935 demonstrated no benefit over placebo in preventing alcohol relapse. Org 25935 was tested as an adjunctive treatment to atypical antipsychotics in predominant persistent negative symptoms of schizophrenia, where it did not differ significantly from placebo in reducing negative symptoms or improving cognitive functioning. Clinical trials against panic disorder did not show any benefit compared to placebo.

Remacemide is a low-affinity noncompetitive NMDA receptor antagonist with sodium channel blocking properties. It has been studied for a number of conditions including acute ischemic stroke, epilepsy, Parkinsons Disease, and Huntington's disease. It was concluded, that was unlikely that remacemide would be further developed as an antiepileptic drug. As for other conditions, there no any information in the literature, why remacemide is no longer being developed for them.

Norcodeine is the N-demethylated derivative of codeine. It has relatively little opioid activity in its own right, but is formed as a metabolite of codeine following ingestion. Codeine and its other major metabolites codeine-6-glucuronide and norcodeine have weak affinity to opioid μ-receptors.