Letermovir (AIC246 or MK-8228), a 3,4-dihydro-quinazoline- 4-yl-acetic acid derivative, is the prototype viral terminase complex inhibitor that is most advanced in its clinical development. The novel compound was initially developed by AiCuris. In April 2011, the drug was granted orphan drug designation for prevention of CMV disease by the European Commission. In August 2011, the US Food and Drug Administration granted it a fast track designation. In 2012, the results of Phase IIb clinical trials using letermovir in bone marrow transplant patients were presented at various international meetings, and the data were subsequently published in 2014.42 It`s continued clinical development is currently undertaken in agreement with Merck. Letermovir is highly potent in vitro and in vivo against cytomegalovirus. Because of a distinct mechanism of action, it does not exhibit cross-resistance with other antiviral drugs. It is predicted to be active against strains that are resistant to ganciclovir, foscarnet, and cidofovir. To date, early-phase clinical trials suggest a very low incidence of adverse effects. It targets the UL56 subunit of the viral terminase complex. Letermovir is currently in Phase III development.

Telotristat (telotristat etiprate) is an ethyl ester prodrug which is hydrolyzed to its active moiety LP-778902 both in vivo and in vitro. Telotristat etiprate is an orally bioavailable, small-molecule, tryptophan hydroxylase (TPH) inhibitor. It is the first investigational drug in clinical studies to target TPH, an enzyme that triggers the excess serotonin production within metastatic neuroendocrine tumor (mNET) cells leading to carcinoid syndrome. Unlike existing treatments of carcinoid syndrome which reduce the release of serotonin outside tumor cells, telotristat etiprate reduces serotonin production within the tumor cells. By specifically inhibiting serotonin production telotristat may provide patients with more control over their disease. Telotristat etiprate has received Fast Track and Orphan Drug designation from the U.S. Food and Drug Administration and has been granted priority review by the FDA with a Prescription Drug User Fee Act (PDUFA) target action date of February 28, 2017.

Lifitegrast (under brand name Xiidra) was approved as an ophthalmic solution for the treatment of the signs and symptoms of dry eye disease. Lifitegrast binds to the integrin lymphocyte function-associated antigen-1 (LFA-1); a cell surface protein found on leukocytes and blocks the interaction of LFA-1 with its cognate ligand intercellular adhesion molecule-1 (ICAM-1). This LFA-1/ICAM-1 interaction is a key step in the inflammatory cascade that contributes to dry eye disease. Besides lifitegrast participates in phase II clinical trials for prevention of the signs and symptoms of allergic conjunctivitis.

Elbasvir is an inhibitor of the Hepatitis C Virus (HCV) Non-Structural protein 5A (NS5A). Elbasvir was approved by the FDA in January 2016 for the treatment of hepatitis C. It was developed by Merck and completed Phase III trials, used in combination with the NS3/4A protease inhibitor grazoprevir under the trade name Zepatier. Zepatier is indicated for treatment of chronic HCV genotype 1 or 4 infection in adults.

Trans-1-amino-3-[(18)F]fluorocyclobutanecarboxylic acid (also known as Fluciclovine (18F)) was approved under brand name AXUMIN as a radioactive diagnostic agent indicated for positron emission tomography (PET) imaging in men with suspected prostate cancer recurrence. Besides, this radioactive compound is used in patients with cervical, ovarian epithelial or endometrial cancers. Fluciclovine F 18 is a synthetic amino acid transported across mammalian cell membranes by amino acid transporters, such as LAT-1 and ASCT2, which are upregulated in prostate cancer cells, but as was shown, this compound has a higher affinity for ASCT2 in comparison with other transporters.

Obeticholic acid (also known as INT-747), is a potent, orally bioavailable farnesoid X receptor (FXR) agonist. The key role of the farnesoid X receptor (FXR) as a regulator of bile and cholesterol metabolism in the liver, with preclinical data from numerous studies providing strong rationale for the advancement of FXR agonists as hepatoprotective therapeutics in chronic liver disease. Obeticholic acid is marketed under the trade name Ocaliva. Ocaliva is specifically indicated for the treatment of primary biliary cholangitis (PBC) in combination with ursodeoxycholic acid (UDCA) in adults with an inadequate response to UDCA, or as monotherapy in adults unable to tolerate UDCA.

Cholic acid is a primary bile acid synthesized from cholesterol in the liver. Endogenous bile acids including cholic acid enhance bile flow and provide the physiologic feedback inhibition of bile acid synthesis. The mechanism of action of cholic acid has not been fully established; however, it is known that cholic acid and its conjugates are endogenous ligands of the nuclear receptor, farnesoid X receptor (FXR). FXR regulates enzymes and transporters that are involved in bile acid synthesis and in the enterohepatic circulation to maintain bile acid homeostasis under normal physiologic conditions. U.S. Food and Drug Administration approved Cholbam (cholic acid) capsules, the first FDA approved treatment for pediatric and adult patients with bile acid synthesis disorders due to single enzyme defects, and for patients with peroxisomal disorders (including Zellweger spectrum disorders).

Eluxadoline, an orally active mixed μ opioid receptor (μOR) agonist δ opioid receptor (δOR) antagonist. Eluxadoline normalizes gastrointestinal (GI) transit and defecation under conditions of novel environment stress or post-inflammatory altered GI function. Allergan (previously Actavis) is developing eluxadoline for the treatment of diarrhoea-predominant irritable bowel syndrome. The agent was originated by Janssen Pharmaceutica. Eluxadoline has been launched in the US under trade name VIBERZI (eluxadoline) tablets, while is at the preregistration stage in the EU.

Sacubitril is a prodrug neprilysin inhibitor used in combination with valsartan (sold under the brand name Entresto among others) to reduce the risk of cardiovascular events in patients with chronic heart failure (NYHA Class II-IV) and reduced ejection fraction. It was approved under the FDA's priority review process for use in heart failure on July 7, 2015. Sacubitril's active metabolite, LBQ657 inhibits neprilysin, a neutral endopeptidase that would typically cleave natiuretic peptides such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and c-type natriuretic peptide (CNP). ANP and BNP are released under atrial and ventricle stress, which activate downstream receptors leading to vasodilation, natriuresis and diuresis. Under normal conditions, neprilysin breaks down other vasodilating peptides and also vasoconstrictors such as angiotensin I and II, endothelin-1 and peptide amyloid beta-protein. Inhibition of neprilysin therefore leads to reduced breakdown and increased concentration of endogenous natriuretic peptides in addition to increased levels of vasoconstricting hormones such as angiotensin II.

Lumacaftor (VX-809) is an investigational drug developed by the Massachusetts-based pharmaceutical company Vertex for the treatment of patients who suffer from cystic fibrosis (CF) and have the F508del mutation in the CF transmembrane conductance regulator (CFTR). Currently, lumacaftor is approved by the U.S. FDA as a combined oral treatment for CF in combination with Kalydeco (ivacaftor). Lumacaftor is commercialized by Vertex under the brand name Orkambi, and Kalydeco was approved in the United States in 2012. The lumacaftor/Kalydeco combo was approved by the FDA in July 2015 for patients ages 12 and older, while the use of lumacaftor alone is still being studied by Vertex. The mechanism of action of lumacaftor is based on the interference with the F508 CFTR. The chronic disease is caused by a mutation in the gene that controls the salt transportation in the cells, resulting in thick, sticky mucus in the respiratory, digestive, and reproductive systems. To address that genetic defect, lumacaftor helps correct the mutated genes with a novel therapeutic approach. Both lumicaftor and kalydeco work by correcting the misfolded CFTR protein, the root cause of the F508del mutation, which led to the approval of the combined treatment by the FDA. However, while kalydeco alone is also approved by the FDA, the use of lumacftor alone has not yet been approved.