AEE-788 is an orally available anticancer agent that was being developed by Novartis. AEE-788 is a dual family epidermal growth factor receptor/ErbB2 and vascular endothelial growth factor receptor tyrosine kinase inhibitor with antitumor and antiangiogenic activity. At the enzyme level, AEE-788 inhibited EGFR and VEGF receptor tyrosine kinases in the nm range (IC(50)s: EGFR 2 nm, ErbB2 6 nm, KDR 77 nm, and Flt-1 59 nm). In cells, growth factor-induced EGFR and ErbB2 phosphorylation was also efficiently inhibited (IC(50)s: 11 and 220 nm, respectively). AEE-788 demonstrated antiproliferative activity against a range of EGFR and ErbB2-overexpressing cell lines (including EGFRvIII-dependent lines) and inhibited the proliferation of epidermal growth factor- and VEGF-stimulated human umbilical vein endothelial cells. These properties, combined with a favorable pharmacokinetic profile, were associated with a potent antitumor activity in a number of animal models of cancer, including tumors that overexpress EGFR and or ErbB2. Oral administration of AEE-788 to tumor-bearing mice resulted in high and persistent compound levels in tumor tissue. Moreover, AEE-788 efficiently inhibited growth factor-induced EGFR and ErbB2 phosphorylation in tumors for >72 h, a phenomenon correlating with the antitumor efficacy of intermittent treatment schedules. AEE-788 has potential as an anticancer agent targeting deregulated tumor cell proliferation as well as angiogenic parameters. AEE-788 had been in phase Ⅱ clinical trials by Novartis for the treatment of glioblastoma multiforme. However, this research has been discontinued.

Denbufylline is a selective xanthine derivative that inhibits PDE IV and has bronchodilatory properties. Shown to exhibit negative inotropic effects by acting on verapamil-sensitive sites of Ca2+ channels in guinea pig ventricle papillary muscle independently of its PDE inhibitory activity. Denbufylline, a selective type 4 phosphodiesterase (PDE-4) inhibitor, is a potent activator of the hypothalamo-pituitary-adrenal (HPA) axis when given orally or intraperitoneally (i.p.) to adult male rats. Denbufylline was being developed as an agent for the therapy of dementia.

Carmegliptin is a potent, long-acting, selective, orally bioavailable, pyrrolidinone-based inhibitor of dipeptidyl peptidase 4 (DPP-4), with hypoglycemic activity. ). DPP-IV is a proline-specific serine protease enzyme that is known to rapidly inactivate two incretin hormones released during food ingestion, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Incretins are essential for regulating both fasting and postprandial plasma glucose by stimulating insulin secretion, supporting β-cell mass, and inhibiting glucagon production by the α-cells to reduce glucose production by the liver. By selectively inhibiting DPP-IV, carmegliptin prolongs the activity of circulating GLP-1 and GIP and improves their potential to prolong the antidiabetic actions. Carmegliptin is indicated for use as monotherapy or in combination with other oral antihyperglycemic agents for the treatment of Type 2 diabetes.

Zaprinast is (M&B 22,948; 2-o-propoxy-phenyl-8-azapurin-6-one) is a selective inhibitor of cyclic GMP (cGMP)-dependent phosphodiesterases, with vasodilation activity in a variety of species and tissues. The potency of zaprinast as a vasorelaxant varies with the species, the tissue, and the presence and absence of endothelium. Zaprinast apparently loses all or most of its vasorelaxant capacity when arteries have been denuded of the endothelial cell layer. Alternatively, the vasorelaxant effects of zaprinast can be attenuated using methylene blue, an inhibitor of soluble guanylate cyclase and hemoglobin inhibitor of nitric oxide synthesis. Therefore, zaprinast-induced relaxations appear to be endothelium-dependent. In human platelets zaprinast, at a dose of 10 mkM, caused a modest (20%) inhibition of aggregation as well as a small increase in cGMP content. In anesthetized rats, zaprinast dose-dependently lowered mean arterial blood pressure (MAP), an effect that correlated well with increased levels of plasma cGMP. Zaprinast decreased mean arterial pressure, the reduction being inversely related to zaprinast concentration. Zaprinast had no effect on heart rate, but increased cardiac output, urinary output, urinary sodium excretion, as well as renal blood flow. Oral administration of zaprinast to spontaneously hypertensive rats at a dose of 200 mg/kg/day normalized blood pressure. In normotensive rats, however, no changes in blood pressure were observed with the same treatment. In an initial placebo-controlled, double-blind crossover trial, 10 mg of zaprinast was effective in reducing exercise-, but not histamine-induced bronchoconstriction in adult asthmatics. However, in a similar study with asthmatic children, zaprinast was ineffective in preventing exercise-induced bronchoconstriction. Since then the clinical development of zaprinast has been discontinued.

Omigapil (CGP 3466 or TCH346) is a structurally related analog of R-(-)-deprenyl that exhibits virtually no monoamine oxidase type B inhibiting activity but is neuroprotective in the picomolar concentration range. It binds to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and at subnanomolar concentrations prevent the S-nitrosylation of GAPDH, inhibit GAPDH-Siah binding and prevent the nuclear translocation of GAPDH. Omigapil demonstrated promising potential in the treatment of Parkinson's disease and motoneuron disease in animal models, however, it did not show efficacy in clinical trials. Omigapil is in development for the treatment of congenital muscular dystrophy.

Merimepodib has immunosuppressive activity. It targets hepatitis C indirectly through the inhibition of inositol monophosphate dehydrogenase, which exerts an acute antiproliferative effect on lymphocyte proliferation due to their almost exclusive dependence on the de novo pathway for synthesis of guanosine. Phase II clinical trial study of merimepodib for the treatment of HCV infection and psoriasis were completed. The poor pharmacokinetic-pharmacodynamic results have resulted in discontinuation of clinical trials.

Daiichi Sankyo developed an inhibitor of acyl-coenzyme A:cholesterol acyltransferases (ACAT1 and ACAT2), pactimibe (also known as CS 505). Pactimibe has been used in trials phase II for reducing the progression of coronary artery disease and in patients with atherosclerosis. However, on October 26, 2005, the company made the decision to discontinue all ongoing clinical studies of pactimibe, because of the secondary endpoints that showed a lower effect of the drug on atherosclerosis than the standard of care alone and no beneficial effect on the frequency of cardiovascular events.

Pamapimod (R-1503, Ro4402257) is a potent and selective inhibitor of p38 mitogen-activated protein kinase alpha. The preclinical data support the conclusion that pamapimod has the ability to inhibit the signs and symptoms of rheumatoid arthritis and other autoimmune diseases. Pamapimod was being developed for use in the treatment of rheumatoid arthritis. There is no clear-cut evidence that pamapimod alone or in the presence of methotrexate is efficacious in subjects with rheumatoid arthritis but it does cause adverse effects. It is unlikely that pamapimod will be useful in the treatment of rheumatoid arthritis.

Relacatib (SB-462795) is a potent and orally bioavailable small molecule inhibitor of cathepsin K that inhibits bone resorption. This has been shown in vitro in human tissue and in vivo in cynomolgus monkeys. The drug was developed for treatment in (postmenopausal) osteoporosis, osteoarthritis and potentially other bone disorders. Interactions with other drugs have been reported, and were subject of investigation of a phase I clinical trial (evaluating interactions of relacatib with ibuprofen, acetaminophen, and atorvastatin).

Senazodan (previously known as MCI 154), a positive inotropic agent that inhibits phosphodiesterase III and possesses a vasodilating property. Senazodan was studied in the phase II clinical trial in Japan in patients with acute heart failure. However, this study was discontinued.