Benorterone (or SKF 7690), a steroidal antiandrogen that was studied in the treatment of acne, seborrhea, and hirsutism in women but was never marketed.

THIOINOSINE (Methylmercaptopurine riboside, NSC- 40774) is a purine derivative with antineoplastic and anti-angiogenic properties. THIOINOSINE is readily converted in cells to its active form, 6-methylmercaptopurine ribonucleoside 5'- monophosphate (MMPR-P), by the enzyme adenosine kinase. THIOINOSINE inhibits amidophosphoribosyltransferase, the first committed step in de novo purine synthesis, and inhibits fibroblast growth factor-2 (FGF2)-induced cell proliferation. It has been used similarly to Mercaptopurine in the treatment of Leukemia. It has being tested in clinical trials for advanced pancreatic cancer.

Apadenoson (BMS-068645) is a selective adenosine 2A agonist that contains a methyl ester group which undergoes esterase hydrolysis to its acid metabolite. Apadenoson had been in phase III clinical trials by Forest (now a part of Allergan) for the treatment of coronary artery disease. However, this study has been terminated.

Lexacalcitol (KH1060) is over 100 times more active than 1alpha,25-dihydroxyvitamin D3 and is of potential interest in the treatment of psoriasis and other diseases characterized by accelerated cell growth and T lymphocyte activation, which was studied in the clinical trial. KH1060 also prevents type I diabetes in the preclinical investigation without significant effects on calcium or bone metabolism. In addition also was shown that neuroblastoma (NB) cell lines were more susceptible to growth inhibition by KH1060, suggesting its possible use in NB to potentiate the action of retinoids, which are in clinical use for this disease. The underlying biochemical reasons for the increased biological activity of KH1060 are unknown, but it can include 1) metabolic considerations in addition to explanations based upon 2) enhanced stability of KH1060-liganded transcriptional complexes.

Lonaprisan is an orally bioavailable pentafluoroethyl derivative of a mifepristone-related steroid with antiprogestagenic activity. Lonaprisan is a pure, highly receptor-selective progesterone receptor (PR) antagonist (both PR isoforms PR-A and PR-B); binding of this agent to PRs inhibits PR activation and the associated proliferative effects. Lonaprisan showed limited efficacy as second-line endocrine therapy in postmenopausal women with PR-positive metastatic breast cancer. Lonaprisan had been in phase II clinical trials by Bayer for the treatment of breast cancer and dysmenorrhea. However, this research has been discontinued.

Afeletecan (Bay 38-3441) is a camptothecin glycoconjugate which stabilizes the active lactone form of camptothecin and allows selective uptake into tumor cells. Afeletecan is a topoisomerase inhibitor. Afeletecan was in phase I clinical trials with Bayer for the treatment of cancer; however, development appears to have been discontinued.

Ciladopa, is a troponylpiperazine derivative and dopamine agonist that has been shown to influence dopaminergic mechanisms in animals. Preclinical pharmacological studies have suggested that it has antiparkinsonian activity similar to that of bromocriptine but without many of the troublesome side effects. Unfortunately in some clinical trials no significant differences was found among the treatment groups and placebo.

Pyrroliphene is a dialkylaminodiphenylbutanol ester with antitussive and analgesic activities. In clinical trials the major side effect of Pyrroliphene was sedation, and the other side effect liabilities were similar to those of morphine.

Enadoline (CI-977) is a potent and selective agonist at the kappa-opioid receptor. Enadoline is a potent antinociceptive agent. Clinical use of enadoline was associated with dose-limiting neuropsychiatric adverse events. Enadoline may yet find some application against ischaemic stroke and severe head injury, presumably in comatose patients.

FLORTANIDAZOLE F-18 is a radioactive tumor hypoxia tracer to potentially identify and quantify the degree of hypoxia in tumors in vivo via positron emission tomography (PET) imaging.