Neratinib (HKI-272) is a pan-HER inhibitor, this irreversible tyrosine kinase inhibitor binds and inhibits the tyrosine kinase activity of epidermal growth factor receptors, EGFR (or HER1), HER2 and HER4, which leads to reduced phosphorylation and activation of downstream signaling pathways. Neratinib is a modified form of the discontinued compound pelitinib, and was originally being develoAdditionally, phase II development of oral neratinib as a neoadjuvant therapy for breast cancer, as a second-line therapy for non-small cell lung cancer, and for other solid tumours is also in progress in numerous countries worldwide. ped by Wyeth (later Pfizer). Oral neratinib is awaiting approval as an extended adjuvant therapy for breast cancer in the EU and in the US. Blocking HER2 function by a small molecule kinase inhibitor, such as neratinib, represents an attractive alternate strategy for the growth inhibition of HER2-positive tumours.

Niraparib (MK-4827) displays excellent PARP 1 and 2 inhibition. Inhibition of PARP in the context of defects in other DNA repair mechanisms provide a tumor specific way to kill cancer cells. Niraparib is in development with TESARO, under licence from Merck & Co, for the treatment of cancers (ovarian, fallopian tube and peritoneal cancer, breast cancer, prostate cancer and Ewing's sarcoma). Niraparib was characterized in a number of preclinical models before moving to phase I clinical trials, where it showed excellent human pharmacokinetics suitable for once a day oral dosing, achieved its pharmacodynamic target for PARP inhibition, and had promising activity in cancer patients. It is currently being tested in phase 3 clinical trials as maintenance therapy in ovarian cancer and as a treatment for breast cancer.

Niraparib (MK-4827) displays excellent PARP 1 and 2 inhibition. Inhibition of PARP in the context of defects in other DNA repair mechanisms provide a tumor specific way to kill cancer cells. Niraparib is in development with TESARO, under licence from Merck & Co, for the treatment of cancers (ovarian, fallopian tube and peritoneal cancer, breast cancer, prostate cancer and Ewing's sarcoma). Niraparib was characterized in a number of preclinical models before moving to phase I clinical trials, where it showed excellent human pharmacokinetics suitable for once a day oral dosing, achieved its pharmacodynamic target for PARP inhibition, and had promising activity in cancer patients. It is currently being tested in phase 3 clinical trials as maintenance therapy in ovarian cancer and as a treatment for breast cancer.

Abemaciclib, previously known as LY2835219, is a potent and selective inhibitor of cyclin-dependent kinases: CDK4 and CDK6, developed by Eli Lilly, which is in clinical trial phase III for the treatment of breast cancer and non-small cell lung cancer (NSCLC) and in phase II for investigation of its treatment glioblastoma and melanoma.

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.

AR-13503 is an active metabolite of Netarsudil

(+)-alpha-Dihydrotetrabenazine (HTBZ) is an active component of tetrabenazine. Tetrabenazine is a mixture of closely-related compounds (isomers) and is readily metabolized in the human body to HTBZ and related isomers. Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorder and is marketed under the trade names Nitoman in Canada and Xenazine in New Zealand and some parts of Europe, and is also available in the USA as an orphan drug. (+)-alpha-Dihydrotetrabenazine and related benzo[a]quinolizines have been labeled with tritium and carbon-11 radioisotopes and used for in vitro and in vivo studies of the VMAT2 in animal and human brain. Adeptio Pharmaceuticals is developing alpha-dihydrotetrabenazine (HTBZ) for the treatment of neurological disorders. It acts by inhibiting vesicular monoamine transporter 2 (VMAT2), thereby blocking the transport of dopamine into axon terminals or into storage vesicles.

Naldemedine (Symproic) is an opioid antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain. Naldemedine is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids. Naldemedine is a derivative of naltrexone to which a side chain has been added that increases the molecular weight and the polar surface area, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldemedine is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, the CNS penetration of naldemedine is expected to be negligible at the recommended dose levels, limiting the potential for interference with centrally-mediated opioid analgesia. Naldemedine was approved in 2017 in both the US and Japan for the treatment of Opioid-induced Constipation.

(+)-alpha-Dihydrotetrabenazine (HTBZ) is an active component of tetrabenazine. Tetrabenazine is a mixture of closely-related compounds (isomers) and is readily metabolized in the human body to HTBZ and related isomers. Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorder and is marketed under the trade names Nitoman in Canada and Xenazine in New Zealand and some parts of Europe, and is also available in the USA as an orphan drug. (+)-alpha-Dihydrotetrabenazine and related benzo[a]quinolizines have been labeled with tritium and carbon-11 radioisotopes and used for in vitro and in vivo studies of the VMAT2 in animal and human brain. Adeptio Pharmaceuticals is developing alpha-dihydrotetrabenazine (HTBZ) for the treatment of neurological disorders. It acts by inhibiting vesicular monoamine transporter 2 (VMAT2), thereby blocking the transport of dopamine into axon terminals or into storage vesicles.

AR-13503 is an active metabolite of Netarsudil