Tiospirone (TSP) is an atypical antipsychotic drug. Tiaspirone appeared to be a promising antipsychotic agent as it didn`t cause extrapyramidal syndromes. It has 5HT-2 antagonistic properties as well as affinity for D2, 5HT-1a, 5HT-6 and sigma receptors. Tiospirone was in phase III clinical trials for the treatment of attention hyperactivity disorder with Mead Johnson in the USA but its development appears to have been discontinued.

Ensaculin is related to naturally occurring benzopyranones like scoparone. The compound is a potent functional antagonist of excitatory amino acid-induced convulsions and mortality. In receptor-binding studies, Ensaculin showed high affinity to dopaminergic (D2, D3), serotoninergic (5-HT1A, 5-HT7), and adrenergic (A1a, A1b) receptors in the nanomolar range. Ensaculin antagonizes NMDA responses in a voltage-dependent manner. Various studies support the notion that this compound could indeed have a broad range of nootropic properties. Although few patients presented postural hypotension and dizziness after receiving ensaculin in phase I clinical trials, this drug candidate was further discontinued in phase III due to potential side effects.

Plinabulin (formerly known as NPI-2358) is a potent microtubule-destabilizing agent that exerts its effect by binding to the colchicine-binding site of tubulin. Plinabulin projects its potent antitumor activity against a broad spectrum of tumor cell lines. This drug in combination with docetaxel is under development by BeyondSpring Pharmaceuticals in a worldwide Phase 3 clinical trial for non-small cell lung cancer. Pegfilgrastim is also in phase II clinical trial for the prevention of chemotherapy-induced neutropenia, where docetaxel, doxorubicin, and cyclophosphamide (TAC) were used as the chemotherapy. Plinabulin also possessed antitumor activity in animal models with multiple myeloma cancer cells, where the JNK protein appeared to be a primary target of plinabulin.

The dihydrochloride salt of nolatrexed, a water-soluble lipophilic quinazoline folate analog with antineoplastic activity. Nolatrexed occupies the folate binding site of thymidylate synthase, resulting in inhibition of thymidylate synthase activity and thymine nucleotide synthesis with subsequent inhibition of DNA replication, DNA damage, S-phase cell cycle arrest, and caspase-dependent apoptosis. This agent also exhibits radiosensitizing activity. Orphan designation of nolatrexed was granted in the Unites States of America for treatment of hepatocellular carcinoma.

Sunepitron (CP-93,393) is an anxiolytic drug with highly selective serotonin 5-hydroxytryptamine 1A autoreceptor agonist, alpha2-adrenergic antagonist, and dopamine D2 agonist properties. Sunepitron hydrochloride had been in Phase III clinical trials by Pfizer for the treatment of anxiety disorder and depression. However, this research has been discontinued.

Lisofylline [1-(5R-hydroxyhexyl)-3,7-dimethylxanthine] is a unique metabolite of pentoxifylline. Lisofylline inhibited the generation of phosphatidic acid and free fatty acids. Lisofylline blocked the release of pro-inflammatory cytokines in oxidative tissue injury, in response to cancer chemotherapy and in experimental sepsis. Lisofylline regulates immune cell function and autoimmune response by inhibition of IL-12 signalling and cytokine production. Lisofylline may have therapeutic value in the prevention of autoimmune disorders, including Type 1 diabetes, autoimmune recurrence following islet transplantation, and in preservation of beta cell functional mass during islet isolation.

Enclomiphene (Androxal), in development by Repros Therapeutics Inc, is a non-steroidal estrogen receptor antagonist that promotes gonadotropin-dependent testosterone secretion by the testes. Enclomiphene constitutes the trans-stereoisomer of clomiphene citrate, a drug that has been widely prescribed for several decades for the treatment of female ovulatory dysfunction. Because of the antagonistic effects of enclomiphene, the drug has the potential to increase serum testosterone levels in men with secondary hypogonadism by restoring physiological endogenous testosterone secretion while maintaining testicular volume and, potentially, spermatogenesis. In clinical trials conducted to date, enclomiphene demonstrated significant efficacy in the physiological restoration of testosterone levels in males with secondary hypogonadism. The compound also exhibited an unanticipated favorable effect on fasting plasma glucose; this result has been accompanied by rapidly accumulating evidence from other researchers for a bidirectional relationship between low serum testosterone and obesity/metabolic syndrome (syndrome X) in men.

Taselisib (GDC-0032) is an highly selective small-molecule inhibitor of phosphatidylinositol 3-kinase (PI3K) p110-α isoform (PIK3CA). Taselisib is designed to bind to the ATP-binding pocket of PIK3CA to potentially prevent subsequent downstream signaling. Taselisib caused a strong differential growth inhibition in carcinoma cells harbored oncogenic PIK3CA mutations. In preclinical studies, taselisib induced growth inhibition in PIK3CA-mutant xenograft mouse models. Genentech (a Roche subsidiary) is developing taselib primarily for the treatment of solid tumours.

Sorbinil (also known as CP-45,634), an aldose reductase inhibitor that has been in phase III clinical trials in preventing the development of diabetic retinopathy and neuropathy in persons with insulin-dependent diabetes. However, this research has been discontinued. It is also known, that sorbinil is oxidatively metabolized to a potentially toxic intermediate.

Linsitinib is an inhibitor of the insulin receptor and the insulin-like growth factor 1 receptor, which may result in the inhibition of tumor cell proliferation and the induction of tumor cell apoptosis. Linsitinib is in phase II clinical trials for the treatment of metastatic prostate carcinoma, gastrointestinal stromal tumors and other cancers. Common adverse events included fatigue, nausea hyperglycaemia and anorexia.