Basimglurant is a potent, selective, and safe mGlu5 inhibitor with good oral bioavailability and long half-life supportive of once-daily administration, good brain penetration, and high in vivo potency. It has antidepressant properties that are corroborated by its functional magnetic imaging profile as well as anxiolytic-like and antinociceptive features. In electroencephalography recordings, basimglurant shows wake-promoting effects followed by increased delta power during subsequent non-rapid eye movement sleep. Basimglurant has favorable drug-like properties, a differentiated molecular mechanism of action, and antidepressant-like features that suggest the possibility of also addressing important comorbidities of MDD including anxiety and pain as well as daytime sleepiness and apathy or lethargy. Basimglurant is being under development by Roche for the treatment of treatment-resistant depression (as an adjunct). It is in phase II clinical trials for this indication.

Motesanib (AMG 706), a novel nicotinamide, was identified as a potent, orally bioavailable inhibitor of the VEGFR1/Flt1, VEGFR2/kinase domain receptor/Flk-1, VEGFR3/Flt4 and Kit receptors. Motesanib was expected to reduce vascular permeability and blood flow in human tumours. A phase III trial of motesanib in combination with paclitaxel and carboplatin in non-squamous NSCLC has been terminated by Takeda and subsequently the development was discontinued. Motesanib has also been investigated up to phase II in breast, thyroid, colorectal and gastrointestinal stromal tumours. However, development has been discontinued in these indications.

Bevirimat (3-O-(3',3'-dimethylsuccinyl) betulinic acid or MPC-4326 or PA-457) potently inhibits replication of both WT and drug-resistant HIV-1 isolates and demonstrate that the compound acts by disrupting a late step in Gag processing involving conversion of the capsid precursor (p25) to mature capsid protein (p24). Bevirimat inhibits replication of both wild-type and drug-resistant HIV-1 isolates in vitro, achieving similar 50% inhibitory concentration values with both categories. Serial drug passage studies have identified six single amino acid substitutions that independently confer bevirimat resistance. These resistance mutations occur at or near the CA-SP1 cleavage site, which is not a known target for resistance to other antiretroviral drugs. Bevirimat has been in phase 2 trial for the treatment of HIV infections. Bevirimat has demonstrated a consistent pharmacokinetic profile in healthy volunteers and HIV-infected patients. The demonstration of an antiviral effect following a single oral dose of bevirimat validates maturation inhibition as a potential target for antiretroviral therapeutics in humans.

Combretastatin A4 is a vascular disrupting agent (VDA) that targets tumor vasculature to inhibit angiogenesis. Combretastatin A4 is a tubulin-binding agent that binds at or near the colchicine binding site of β-tubulin and inhibits tubulin assembly. This tubulin-binding agent was originally isolated from an African shrub, Combretum caffrum. Combretastatin A4 is cytotoxic to umbilical-vein endothelial cells (HUVECs) and to a range of cells derived from primary tumors and these cytotoxicity profiles have been used to assess several novel analogs of the drug for future development. Combretastatin A4 has antitumor activity by inhibiting AKT function. The inhibited AKT activation causes decreased cell proliferation, cell cycle arrest, and reduced in vitro migration/invasiveness and in vivo metastatic ability. Several studies in mice have shown that a single administration of combretastatin A4 (100 mg/kg) does not significantly affect primary tumor growth. However, repeated administration (12.5 – 25.0mg/kg twice daily) for periods of 10 – 20 days resulted in approximately 50% retardation of growth of ectopic Lewis lung carcinoma and substantial growth delay of T138 spontaneous murine breast tumors. In clinical studies, Combretastatin A4 has been well tolerated in patients at doses up to 56 mg/m2, following a protocol of five daily 10-minute intravenous infusions every 21 days. The disodium combretastatin A4 phosphate prodrug is currently undergoing clinical trials in the UK and USA.

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.

Alvocidib (also known as Flavopiridol or HMR-1275) is a flavonoid alkaloid CDK9 kinase inhibitor under clinical development for the treatment of acute myeloid leukemia, by Tolero Pharmaceuticals, Inc. As a broad spectrum CDK inhibitor, Alvocidib can inhibit cell cycle progression in either G1 or G2 and induces G1 arrest in either MCF-7 or MDA-MB-468 cells by inhibition of the CDK4 or CDK2 kinase activity. Alvocidib exhibits potent cytotoxicity against a wide variety of tumor cell lines (LNCAP, HCT116, A2780, K562, PC3, and Mia PaCa-2) with IC50 values ranging from 16 nM for LNCAP to 130 nM for K562. Administration of Alvocidib at 7.5 mg/kg for 7 days displays slight antitumor activity against P388 murine leukemia, and active against the human A2780 ovarian carcinoma implanted sc in nude mice). Alvocidib treatment at 1-2.5 mg/kg for 10 days significantly suppresses collagen-induced arthritis in mice in a dose-dependent manner, by inhibiting synovial hyperplasia and joint destruction, whereas serum concentrations of anti-collagen type II (CII) Abs and proliferative responses to CII are maintained. Tolero Pharmaceuticals Inc. announced that the FDA has granted orphan drug designation for Alvocidib, its cyclin-dependent kinase small molecule inhibitor, for the treatment of patients with acute myeloid leukemia.

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.

P-Cresol is an end product of protein breakdown and also it is a fermentation metabolite of tyrosine. The mechanisms underlying colonic carbohydrate and protein fermentation, responsible for the generation of p-cresol, are only partially understood. After absorption, the majority of p-cresol is conjugated to form p-cresyl sulphate. There is clear evidence, both in vitro and in vivo, that accumulation of conjugated fermentation metabolites is correlated with clinical important endpoints. In renal failure, the colonic generation rate of p-cresol is markedly elevated. Free p-cresol is an independent predictor for mortality in hemodialysis patients. The accumulation of p-cresol increases the cardiovascular risk of chronic kidney disease (CKD) patients. It was shown, that p-cresol l triggered autophagic renal proximal tubular cells death via JNK-mediated p62 accumulation and then activated caspase 8-dependent cell death pathway. Thus p-cresol can be considered as one of the key events causing progression of CKD, which might affect drug disposition in CKD cases.

Lesinurad (brand name Zurampic) is a urate transporter inhibitor for treating hyperuricemia associated with gout in patients who have not achieved target serum uric acid levels with a xanthine oxidase inhibitor alone. In gout patients, Lesinurad lowered serum uric acid levels and increased renal clearance and fractional excretion of uric acid. Following single and multiple oral doses of Lesinurad to gout patients, dose-dependent decreases in serum uric acid levels and increases in urinary uric acid excretion were observed. Lesinurad reduces serum uric acid levels by inhibiting the function of transporter proteins involved in uric acid reabsorption in the kidney. Lesinurad inhibited the function of two apical transporters responsible for uric acid reabsorption, uric acid transporter 1 (URAT1) and organic anion transporter 4 (OAT4), with IC50 values of 7.3 and 3.7 µM, respectively. URAT1 is responsible for the majority of the reabsorption of filtered uric acid from the renal tubular lumen. OAT4 is a uric acid transporter associated with diuretic-induced hyperuricemia. Lesinurad does not interact with the uric acid reabsorption transporter SLC2A9 (Glut9), located on the basolateral membrane of the proximal tubule cell. Based on in vitro studies, lesinurad is an inhibitor of OATP1B1, OCT1, OAT1, and OAT3; however, lesinurad is not an in vivo inhibitor of these transporters. In vivo drug interaction studies indicate that lesinurad does not decrease the renal clearance of furosemide (substrate of OAT1/3), or affect the exposure of atorvastatin (substrate of OATP1B1) or metformin (substrate of OCT1). Based on in vitro studies, lesinurad has no relevant effect on P-glycoprotein.

Lesinurad (brand name Zurampic) is a urate transporter inhibitor for treating hyperuricemia associated with gout in patients who have not achieved target serum uric acid levels with a xanthine oxidase inhibitor alone. In gout patients, Lesinurad lowered serum uric acid levels and increased renal clearance and fractional excretion of uric acid. Following single and multiple oral doses of Lesinurad to gout patients, dose-dependent decreases in serum uric acid levels and increases in urinary uric acid excretion were observed. Lesinurad reduces serum uric acid levels by inhibiting the function of transporter proteins involved in uric acid reabsorption in the kidney. Lesinurad inhibited the function of two apical transporters responsible for uric acid reabsorption, uric acid transporter 1 (URAT1) and organic anion transporter 4 (OAT4), with IC50 values of 7.3 and 3.7 µM, respectively. URAT1 is responsible for the majority of the reabsorption of filtered uric acid from the renal tubular lumen. OAT4 is a uric acid transporter associated with diuretic-induced hyperuricemia. Lesinurad does not interact with the uric acid reabsorption transporter SLC2A9 (Glut9), located on the basolateral membrane of the proximal tubule cell. Based on in vitro studies, lesinurad is an inhibitor of OATP1B1, OCT1, OAT1, and OAT3; however, lesinurad is not an in vivo inhibitor of these transporters. In vivo drug interaction studies indicate that lesinurad does not decrease the renal clearance of furosemide (substrate of OAT1/3), or affect the exposure of atorvastatin (substrate of OATP1B1) or metformin (substrate of OCT1). Based on in vitro studies, lesinurad has no relevant effect on P-glycoprotein.