Telcagepant (MK-0974) is a calcitonin gene-related peptide receptor antagonist. Merck & Co was developing telcagepant for the treatment of pain. Telcagepant is an extremely potent CGRP antagonist with a Ki = 0.77 (0.07 nM). Telcagepant showed efficacy against acute migraines; however, different patient populations may show more beneficial effects with telcagepant versus triptans. In the acute treatment of migraine, Telcagepant was found to have equal potency to rizatriptan and zolmitriptan in two Phase III clinical trials. Merck & Co has now terminated development of the drug.

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.

Pardoprunox is a partial D2/3 dopamine receptor agonist and full 5-HT1A serotonin receptor agonist. Partial D(2/3) dopamine (DA) receptor agonists provide a novel approach to the treatment of the motor symptoms of Parkinson's disease that may avoid common dopaminergic side effects, including dyskinesia and psychosis. Pardoprunox passed phase III clinical trial for the treatment of Parkinson's disease.

Ruboxistaurin is an orally bioavailable, selective, potent inhibitor of protein kinase C β developed for treating diabetic retinopathy. In vitro and in vivo non-clinical models have demonstrated that Ruboxistaurin decreases PKC β activity and ameliorates many of the effects of PKC β on pathologic processes in the retina. Ruboxistaurin prevents the slowing of retinal blood flow that is observed by fluorescein video angiography in the eyes of diabetic rats. It is also reported to cause regression of retinal neovascularization produced by laser-induced major branch vein occlusions in a porcine model. Ruboxistaurin positively affected the diabetes-induced retinal blood flow abnormalities in a Phase Ib study in diabetic patients. Ruboxistaurin is in phase III clinical trials for the treatment of diabetic nephropathy and diabetic macular edema. Eli Lilly had submitted Ruboxistaurin for approval in the US and the EU; however, the company subsequently discontinued development as it was unable to demonstrate sufficient efficacy

Zosuquidar (LY-335979) is an experimental antineoplastic drug. It is is a potent modulator of P-glycoprotein-mediated multi-drug resistance with Ki of 60 nM. Zosuqidar was initially characterized by Syntex Corporation, which was acquired by Roche in 1990. Roche licensed the drug to Eli Lilly in 1997. It was granted orphan drug status by the FDA in 2006 for AML. Zosuquidar Trihydrochloride had been in phase III clinical trials by Kanisa Pharmaceuticals for the treatment of acute myeloid leukaemia. However, this research has been discontinued.

Carabestine is the active first-pass metabolite of Ebastine and acts as a histamine H1 receptor antagonist which has been investigated as a potential allergy medication. Ebastine is marketed under a number of brand names.

Apricitabine (ATC) is an investigational drug that was being studied for the treatment of HIV infection. Apricitabine belongs to a class (group) of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs). NRTIs block an HIV reverse transcriptase. By blocking reverse transcriptase, NRTIs prevent HIV from multiplying and can reduce the amount of HIV in the body. In vitro studies have shown that apricitabine appears to work on certain HIV strains against which other FDA-approved NRTIs, such as lamivudine (brand name: Epivir), may no longer work. Apricitabine shows antiviral activity in vitro against HIV-1 strains and clinical isolates with mutations in the reverse transcriptase that confer resistance to other NRTIs, including M184V, thymidine analogue mutations (TAMs), nucleoside-associated mutations such as L74V and certain mutations at codon 69. Apricitabine has shown activity in treatment-experienced HIV-1-infected patients with NRTI resistance (with M184V and up to five TAMs) as well as in treatment-naive patients. The study of apricitabine as an HIV medicine was discontinued in 2016. The company developing the drug decided to stop their clinical trials due to a lack of funding and a lack of interest in apricitabine’s early access program.

Anacetrapib is a CETP inhibitor being developed by Merck to treat hypercholesterolemia (elevated cholesterol levels) and prevent cardiovascular disease. Anacetrapib is a cholesterol ester transfer protein (CETP) inhibitor that blocks the transfer of cholesterol from highdensity lipoprotein to other lipoproteins. This results in an increase in high-density lipoprotein cholesterol (HDL-C) and a decrease in lowdensity lipoprotein cholesterol (LDL-C), which may reduce the development of atherosclerosis. Anacetrapib has not been approved for sale in Canada or the United States. Clinical evidence to support the use of anacetrapib for dyslipidemia has been reported in two clinical trials. REVEAL is an ongoing, large-scale phase 3 trial evaluating the effectiveness of anacetrapib with a statin for the secondary prevention of major coronary events in patients who have a history of cardiovascular disease. Results are anticipated in January 2017.

Enzastaurin is a serine/threonine kinase inhibitor that showed antiangiogenic, antiproliferative, and proapoptotic properties in vitro and antitumor activity in vivo in a xenograft Waldenström macroglobulinemia (WM) model. Enzastaurin (LY317615) is a potent PKCβ selective inhibitor. Enzastaurin suppresses angiogenesis and was advanced for clinical development based upon this antiangiogenic activity. Enzastaurin suppresses tumor growth through multiple mechanisms: direct suppression of tumor cell proliferation and the induction of tumor cell death coupled to the indirect effect of suppressing tumor-induced angiogenesis. Enzastaurin is an orally administered drug that was intended for the treatment of solid and haematological cancers. Enzastaurin had shown encouraging preclinical results for the prevention of angiogenesis, inhibition of proliferation and induction of apoptosis as well as showing limited cytotoxicity within phase I clinical trials. However, during its assessment in phase II and III clinical trials the efficacy of enzastaurin was poor both in combination with other drugs and as a single agent. Eli Lilly discontinued development of enzastaurin after top-line data from the double-blind, international Phase III PRELUDE trial in 758 DLBCL patients showed that enzastaurin missed the primary endpoint of improving DFS vs. placebo.

Acolbifene, the active metabolite of EM-800, was identified as a pure antagonist that acts on both activation domains of the ERs. It is in Phase III clinical trials for the prevention of breast cancer and vasomotor symptoms (Hot flush) in postmenopausal women. Most commonly reported adverse events included irregular menses, leg/muscle cramps, diarrhea, and hot flashes. No serious adverse events were reported.