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.

Fluorocyclopentenylcytosine (RX-3117) is a novel small molecule nucleoside compound that is incorporated into DNA or RNA of cancer cells and inhibits both DNA and RNA synthesis which induces apoptotic cell death of tumor cells. Fluorocyclopentenylcytosine also mediates the down-regulation of DNA methyltransferase 1 (DNMT1), an enzyme responsible for the methylation of cytosine residues on newly synthesized DNA and also a target for anticancer therapies. Preclinical studies have shown Fluorocyclopentenylcytosine to be effective in both inhibiting the growth of various human cancer xenograft models, including colon, lung, renal and pancreas, as well as overcoming chemotherapeutic drug resistance. Fluorocyclopentenylcytosine has demonstrated a broad spectrum anti-tumor activity against 50 different human cancer cell lines and efficacy in 12 different mouse xenograft models. The efficacy in the mouse xenograft models was superior to that of gemcitabine. In addition, in human cancer cell lines made resistant to the anti-tumor effects of gemcitabine, Fluorocyclopentenylcytosine still retains its full anti-tumor activity. In August 2012, Rexahn reported the completion of an exploratory Phase I clinical trial of Fluorocyclopentenylcytosine in cancer patients conducted in Europe, to investigate the oral bioavailability, safety and tolerability of the compound. In this study, oral administration of Fluorocyclopentenylcytosine demonstrated an oral bioavailability of 34-58% and a plasma half-life (T1/2) of 14 hours. In addition, Fluorocyclopentenylcytosine was safe and well tolerated in all subjects throughout the dose range tested. Fluorocyclopentenylcytosine is in phase I/II clinical trials by Rexahn for the treatment of bladder cancer and pancreatic cancer. This compound was granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) for the treatment of patients with pancreatic cancer in September 2014.

SAR407899 is a potent, ATP-competitive Rho kinase inhibitor. It antihypertensive action in animals. Sanofi is developing SAR 407899 for the treatment of microvascular angina (Syndrome X). It was previously being developed in clinical trials for the treatment of diabetic neuropathies, diabetic nephropathies, erectile dysfunction, pulmonary hypertension, hypertension and kidney disorders, but development was discontinued for those indications.

Filgotinib (GLPG0634) is a highly selective JAK1 inhibitor. GLPG0634 is a promising drug candidate for the future treatment of autoimmune and inflammatory disorders. It is in phase III clinical trials (initiated mid-2016) for the treatment of rheumatoid arthritis, Crohn's disease and ulcerative colitis. Most common adverse events observed were infections, gastrointestinal disorders and nervous system disorders.

Omtriptolide (previously known as PG490-88 or F60008), an immunosuppressant that has been shown to be the safe and potent antitumor agent and it has been approved entry into Phase I clinical trial for the treatment of prostate cancer in the USA. In addition, the drug is participating in phase I clinical trial for the treatment of myeloid leukemia. Experiments on animals have shown omtriptolide was highly effective in the prevention of murine graft-versus-host disease (GVHD). The immunosuppressive effect of the drug was mediated by inhibition of alloreactive T cell expansion through interleukin-2 production. However, this study was discontinued. Recently published article has shown omtriptolide possesses the potential as a prophylactic agent to prevent ischemia/reperfusion (I/R)-induced lung injury.

Ipatasertib (LCL161) binds to inhibitors of apoptosis proteins (IAPs) with high affinity and initiates the destruction of cIAP1 and cIAP2, which further induces apoptosis via caspase activation. Ipatasertib is advancing in clinical development including five Phase 2 trials in patients with Breast cancer, Multiple myeloma, Myelofibrosis, Small cell lung cancer and Ovarian cancer. The most common LCL161-related adverse events were nausea and vomiting.

NLG919 is a novel small-molecule IDO-pathway inhibitor. NLG919 potently inhibits this pathway in vitro and in cell-based assays. It is orally bioavailable and has a favorable pharmacokinetic and toxicity profile. In mice, a single oral administration of NLG919 reduces the concentration of plasma and tissue Kyn by ∼ 50%. Using IDO-expressing human monocyte-derived DCs in allogeneic MLR reactions, NLG919 potently blocked IDO-induced T cell suppression and restored robust T cell responses with an ED50=80 nM. Similarly, using IDO-expressing mouse DCs from tumor-draining lymph nodes, NLG919 abrogated IDO-induced suppression of antigen-specific T cells (OT-I) in vitro. In vivo, in mice bearing large established B16F10 tumors, administration of NLG919 markedly enhanced the anti-tumor responses of naïve, resting pmel-1 cells to vaccination with cognate hgp100 peptide plus CpG-1826 in IFA

AZD-3759 is an oral inhibitor of both wild-type and mutant EGFR with IC50 values in nanomolar range. The drug was discovered by AstraZeneca for the treatment of non-small-cell lung cancer with CNS metastases. AZD-3759 can penetrate the blood-brain barrier and was confirmed to be effective in vitro with NSCLC cell lines as well as in mouse model of brain metastases. AZD-3759 is currently in Phase 1 clinical trial.

Barasertib (AZD1152) is a dihydrogen phosphate prodrug of a pyrazoloquinazoline Aurora kinase inhibitor [AZD1152–hydroxyquinazoline pyrazol anilide (HQPA)] and is converted rapidly to the active AZD1152-HQPA in plasma. AstraZeneca was developing the aurora kinase inhibitor, barasertib (AZD 1152) as a therapeutic for cancer. AZD1152-HQPA is a highly potent and selective inhibitor of Aurora B (Ki, 0.36nmol/L) compared with Aurora A (Ki, 1,369nmol/L) and has a high specificity versus a panel of 50 other kinases. Consistent with inhibition of Aurora B kinase, addition of AZD1152-HQPA to tumour cells in vitro induces chromosome misalignment, prevents cell division, and consequently reduces cell viability and induces apoptosis. Barasertib (AZD1152) potently inhibited the growth of human colon, lung, and haematologic tumour xenografts (mean tumour growth inhibition range, 55% to ≥100%; P < 0.05) in immunodeficient mice. Detailed pharmacodynamic analysis in colorectal SW620 tumour-bearing athymic rats treated i.v. with Barasertib (AZD1152) revealed a temporal sequence of phenotypic events in tumours: transient suppression of histone H3 phosphorylation followed by accumulation of 4N DNA in cells (2.4-fold higher compared with controls) and then an increased proportion of polyploid cells (>4N DNA, 2.3-fold higher compared with controls). Histologic analysis showed aberrant cell division that was concurrent with an increase in apoptosis in AZD1152-treated tumours. Bone marrow analyses revealed transient myelosuppression with the drug that was fully reversible following cessation of Barasertib (AZD1152) treatment. Barasertib (AZD1152) was in phase III for the treatment of Acute myeloid leukaemia, but later these studies were discontinued.

SAR407899 is a potent, ATP-competitive Rho kinase inhibitor. It antihypertensive action in animals. Sanofi is developing SAR 407899 for the treatment of microvascular angina (Syndrome X). It was previously being developed in clinical trials for the treatment of diabetic neuropathies, diabetic nephropathies, erectile dysfunction, pulmonary hypertension, hypertension and kidney disorders, but development was discontinued for those indications.