Begacestat (GSI-953 or PF-5212362), a gamma-secretase inhibitor (GSI) that selectively inhibits cleavage of APP over Notch, was discovered for the treatment of Alzheimer's disease. The drug has shown promise results in phase I clinical trials, however further studies were discontinued.

Valategrast (R-411) is a dual-acting α4/β1 - α4/β7 integrin antagonist which underwent clinical development with Roche for the treatment of multiple sclerosis (MS) and asthma. Phase I and II studies have been conducted. It had shown good efficacy in animal disease models. Following oral administration, R-411 was rapidly and completely biotransformed into its active metabolite, RO-0270608, most of which was eliminated by biliary excretion. R-411 had shown acceptable pharmacokinetics and good safety in healthy volunteers. R-411 inhibited eosinophil and T H 2 cell excitation and survival, and inhibited eosinophil migration from blood to pulmonary tissues. The idea of combining R-411 with montelukast (leukotriene antagonist) in the pharmaceutical dosage forms, therefore, provided a therapeutic treatment that had the combined effect of reducing circulating eosinophil counts and reducing eosinophil egress into pulmonary tissues, thereby providing an early onset of bronchodilation as well as sustained anti-inflammatory effects. Valategrast had been in phase II clinical trials by Roche for the treatment of asthma and in phase I clinical trials for the treatment of multiple sclerosis (MS). However, the study had been discontinued. Development of Valategrast was discontinued for the treatment of asthma after clarification of the regulatory framework for that class of compounds.

Levisoprenaline (l-isoproterenol) is beta1- and beta2-adrenoreceptor agonist. In Japan, continuous inhalation of levisoprenaline is a recommended treatment for pediatric patients with acute severe exacerbation. Compared with salbutamol, l-isoproterenol reduced modified pulmonary index score more rapidly. But in most countries do not recommend continuous inhalation of l-isoproterenol to treat pediatric patients with acute severe exacerbation of asthma due to worsening asthma control. Levisoprenaline was used to cause experimental chronic heart failure in rats.

Tiotidine is a controversial histamine H2 receptor ligand with negligible activity against H1- and H3- receptors. It was found that tiotidine behaves as an inverse agonist in U-937 cells, diminishing basal cAMP levels. Tiotidine showed two binding sites, one with high affinity and low capacity and the other with low affinity and high capacity. Tiotidine is currently in use as a radioligand in histamine H2-receptor binding studies. Compared to cimetidine, tiotidine appears to be approximately eight times more potent on a molar basis than cimetidine as an inhibitor of acid secretion, and the tiotidine effect is more prolonged. It was developed for the treatment of peptic ulcer.

Ridogrel is a dual action drug used for the prevention of systemic thrombo-embolism and as an adjunctive agent to thrombolytic therapy in acute myocardial infarction. Ridogrel, a combined thromboxane synthase inhibitor, and receptor antagonist is used with streptokinase as an adjunctive therapy to reduce the formation and size of blood clots. Blood clots can cause ischemic cardiac events (heart attacks). Ridogrel has the dual property of inhibiting the synthesis of thromboxane and blocking the receptors of thromboxane/prostaglandin/endoperoxides. It has been shown to accelerate the speed of recanalization and to delay or prevent reocclusion during systemic thrombolysis with tissue plasminogen activator (streptokinase). Ridogrel is a more potent antiplatelet agent than aspirin and might offer an advantage over aspirin as an adjunct to thrombolysis in patients suffering from acute myocardial infarction. While aspirin inhibits cyclooxygenase, the enzyme responsible for producing thromboxane, ridogrel inhibits thromboxane synthesis directly. Ridogrel has been studied primarily as an adjunctive agent to thrombolytic therapy in acute MI (AMI). Despite positive results from initial pilot studies, the largest clinical study, the Ridogrel versus Aspirin Patency Trial (RAPT) failed to demonstrate any advantage with this agent over aspirin. In the study of 907 patients with AMI, there was no difference in the primary endpoint of infarct vessel patency rate between those randomized to ridogrel (72.2%) or aspirin (75.5%). Various mechanisms are likely responsible for the results seen with ridogrel in clinical trials, including potentially ineffective thromboxane receptor inhibition with the concentrations of ridogrel used in human studies. As such, there currently are no clinical indications for preferential use of ridogrel over aspirin.

UK-390957 is a selective serotonin reuptake inhibitor (SSRI) that was in phase II/III development in the USA, European Union and other territories with Pfizer, for the treatment of Premature ejaculation. UK-390957 represented a major development in sexual medicine, and offered patients the convenience of on-demand dosing, significant improvements in IELT, ejaculatory control, and sexual satisfaction with minimal adverse effects. However development of UK-390957 was discontinued.

Thiamiprine is a cytotoxic purine derivative patented by Wellcome Foundation Ltd. as an immunosuppressive and antineoplastic agent. In preclinical models, Thiamiprine is active against a variety of transplantable rodent tumors and in the rat adjuvant arthritis model.