Dinaline represents a group of pharmacologically active lipophilic substances with a relatively simple structure derived from N-acyl-o-phenylenediamine. It has been found to exhibit high antineoplastic activity in a series of slowly growing tumors such as chemically induced rat mammary and colorectal carcinomas, osteosarcoma C22LR and Brown Norway myeloid leukemia. The drug was inactive against many of the typically hypersensitive signal tumors, i.e. mouse leukemias P388 and L1210, sarcoma 180 and Yoshida sarcoma. Colon carcinoma cells exposed to dinaline demonstrate distinct but reversible changes in amino acid transport, protein metabolism, DNA synthesis and cell proliferation.

Ciluprevir (BILN-2061) is a selective inhibitor of the HCV NS3 serine protease, which was developed by Boehringer Ingelheim for the treatment of hepatitis C infection. The drug was discontinued in phase II due to adverse events such as cardiac toxicity (demonstrated in animals). In the cell-based replicon assay, ciluprevir inhibited HCV RNA replication at low nanomolar levels. It had inhibitory rate constant (Ki) values of 0.3 and 0.66 nM for the NS3 proteases of HCV genotypes 1a and -1b, respectively.

KW-2449, a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase, is under investigation to treat leukaemia patients. KW-2449 is a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase with IC50 values of 6.6nM, 14nM, 4nM and 48nM, respectively. KW-2449 has potent growth inhibitory activity against various types of leukaemia by several mechanisms of action. Kyowa Hakko Kirin Pharma Inc. (a US subsidiary of Kyowa Hakko Kirin Co) was developing KW-2449 for the treatment of acute lymphoblastic leukaemia; acute myeloid leukaemia; chronic myeloid leukaemia; myelodysplastic syndromes, but later these studies were discontinued.

Vicriviroc or SCH 417690 is a potent and selective antagonist of the CCR5 receptor. vicriviroc binds specifically to the CCR5 receptor and prevents infection of target cells by CCR5-tropic HIV-1 isolates. In antiviral assays, vicriviroc showed potent, broad-spectrum activity against genetically diverse and drug-resistant HIV-1 isolates and was consistently more active than SCH-C in inhibiting viral replication. This compound demonstrated synergistic anti-HIV activity in combination with drugs from all other classes of approved antiretrovirals. Competition binding assays revealed that vicriviroc binds with higher affinity to CCR5 than SCH-C. Functional assays, including inhibition of calcium flux, guanosine 5'-[35S]triphosphate exchange, and chemotaxis, confirmed that vicriviroc acts as a receptor antagonist by inhibiting signaling of CCR5 by chemokines. Finally, vicriviroc demonstrated diminished affinity for the human ether a-go-go related gene transcript ion channel compared to SCH-C, suggesting a reduced potential for cardiac effects. Vicriviroc represented a promising new candidate for the treatment of HIV-1 infection. Vicriviroc for HIV treatment was previously in Phase III studies but has since been discontinued.

Liarozole is an imidazole-containing compound that inhibits the cytochrome P-450-dependent metabolism of all-trans-retinoic acid (RA). Liarozole, a retinoic acid (RA) metabolism-blocking agent (RAMBA) in clinical development, has been granted orphan drug designation for congenital ichthyosis by the European Commission and the U.S. Food and Drug Administration. Later, based on the mixed results from a phase II/III trial of liarozole for the treatment of ichthyosis, Barrier decided to discontinue the development of liarozole. Liarozole displays antitumor activity against androgen-dependent and independent rat prostate carcinomas.A large phase III international study was completed comparing liarozole 300 mg twice daily with cyproterone acetate (CPA) 100 mg twice daily in a total of 321 patients with metastatic prostate cancer in relapse after first-line endocrine therapy. The results indicate that liarozole might be a possible treatment option for prostate cancer (PCA) following failure of first-line endocrine therapy.

Mivotilate is an orally active hepatoprotective agent for the treatment of liver cirrhosis and hepatitis-B infection. Mivotilate was shown to exert multiple effects on the hepatic cytochrome P450 system, particularly to inhibit CYP2E1 expression and to up-regulate the CYP1A1 expression. The low oral bioavailability of Mivotilate in rats could be primarily attributed to poor absorption and considerable hepatic and gastrointestinal first-pass effects. The thermal reversible microemulsion system of YH439 greatly enhances the bioavailability of YH439 after oral administration. Mivotilate prevents mutagenesis caused by agents such as benzopyrene and reduces skin tumours induced by these agents.

CYC-116 is a novel, ATP-competitive, pyrimidine drug that is taken by mouth as a capsule. The drug is a selective agent that potently inhibits the enzymes Aurora kinases and VEGFR-2 kinase at comparable levels with a range of 19 to 69 nanomolar. Median potency of CYC-116 in cancer cells is approximately 300 nanomolar. CYC-116 has demonstrated a broad spectrum of potent cytotoxic activity against human tumor cell types. Non-clinical efficacy of CYC-116 has been demonstrated by the oral route using mouse leukemia models, in which increased survival was observed, and human solid tumor xenograft models, in which reductions in tumor growth were observed. Cancer cell types that appear to be particularly sensitive to CYC-116 are leukemia, non-small cell lung cancer and pancreatic cancer. CYC-116 works by affecting the cell cycle progression of cancer cells before they enter mitosis or divide to create daughter cancer cells. The mechanism of action of CYC-116 affects cancer cells in several ways. CYC-116-treated cells display delayed entry into mitosis; defective polymerization of tubulins, or proteins that make up microtubules which are the target of the taxane drugs; changes in the function of the centrosome, or the cell's microtubule organizing center; and formation of the mitotic spindle, or the highway along which chromosomes and cellular materials are transported from the mother cell to the daughter cells. After cancer cells are treated with CYC-116, their spindle checkpoint is inactivated resulting in inhibition of cytokinesis or the process by which a mother cell divides. These defects result in the generation of polyploidy or cells with more than two chromosome sets, multinucleated cells or cells with multiple cores and apoptosis or cancer cell death. In a mouse model of leukemia CYC116-treatment induced decreases in tumor cell volume and infiltration of leukemic cells in the bone marrow and resulted in an increase in life span. No significant effects on body weight or normal bone marrow cells were observed at effective doses of CYC-116. Tumor neovascularization, or creation of new blood vessels around a tumor, was significantly reduced in a dose dependent manner. The data confirm that CYC-116 acts as a dual mitotic and angiogenesis inhibitor, a combination of anti-cancer mechanisms which could have therapeutic benefit in the clinic. CYC-116 is currently being studied in a Phase 1 trial in patients with solid tumors at Roswell Park Cancer Institute in Buffalo, New York, and South Texas Accelerated Research Therapeutics (START) in San Antonio. The study is designed to identify the maximum tolerated dose of CYC-116 and evaluate its pharmacokinetic, pharmacodynamic and anti-tumor effects.

Denotivir is an organic chemical compound with antiviral activity. In vitro antiviral activity of denotivir has been demonstrated against human HSV types 1 and 2, and varicella zoster virus (VZV). Clinical trials with vratizolin have given impressive results in the patients with local HSV infections and very good results in VZV infections. Genital herpes, a sexually transmitted HSV infection, whose incidence is increasing and whose treatment has never been adequate, appears to respond well to the treatment with vratizolin with very good results. Very good therapeutic results were also obtained by applying vratizolin to the patients with an ophthalmic HSV infection. Vratizolin exerted strong immunosuppressive actions. Vratizolin inhibited to some degree LPS-induced cytokine production in human peripheral blood cultures. The activities of TNF-alpha, IL-1 and IL-6 were inhibited on average by 37, 26 and 35%, respectively.

Vadimezan (5,6-dimethyl(xanthenone-4-acetic acid), ASA404, DMXAA) is a fused tricyclic analogue of flavone acetic acid with potential antineoplastic activity. In pre-clinical mouse tumour models it was demonstrated that administration of Vadimezan rapidly leads to disruption of the existing vasculature in the tumour and consequent haemorrhagic necrosis of the tumour. This was consistent with the finding that a single dose of Vadimezan induced a prolonged reduction in the growth of xenografted tumours in animal models. The ability to disrupt the vasculature in these pre-clinical models has been attributed to a rapid induction of cytokines, particularly TNFα (tumour necrosis factor α), serotonin and nitric oxide, resulting in hemorrhagic necrosis and a decrease in angiogenesis. Despite the fact that the molecular targets for the drug remained unknown, the promising pre-clinical results led to Vadimezan being selected for clinical development. Results of Phase I trials showed some restriction of tumour blood flow within 24 h of treatment, although this was not as dramatic as seen in pre-clinical models. Unlike the animal models, there was also very little evidence for the rapid death of blood vessels or for increases in TNFα levels in human tumors. No difference in antitumour activity, cytokine induction or toxicity was observed between two parallel Phase I trials, one dosed weekly and the other dosed every 3 weeks. Therefore the drug proceeded to Phase II clinical trials, dosed every 21 days in combination with chemotherapeutic agents. These trials indicated the drug had small benefits in the treatment of non-small-cell lung cancer and prostate cancer. However, a subsequent Phase III clinical trial was not able to reproduce this response and clinical development was halted.