Flurocitabine is an anti-metabolite that was developed by Hoffmann-La Roche for the treatment of cancer. The drug is metabolized to 2 biologically active substances, AFC (1-beta-D-arabinofuranosyl-5-fluorocytosine) and AFU (arabinofuranosyl-5-fluorouracil). Flurocitabine was tested against stomach cancer, pancreatic cancer, small cell lung cancer and AML, however, the development was terminated in the early phases.

Emricasan (IDN- 6556 or PF-03491390) (3-[2-[(2-tert-butyl-phenylaminooxalyl)-amino]-propionylamino]-4-oxo-5-(2,3,5,6-tetrafluoro-phenoxy)-pentanoic acid) is a pan-caspase inhibitor. Testing in vitro enzyme assays demonstrated that emricasan efficiently inhibits all human caspases at low nanomolar concentrations. Preclinically, emricasan was effective in inhibiting apoptosis of sinusoidal endothelial cells. Emricasan has marked efficacy in models of liver disease after oral administration and thus, is an excellent candidate for the treatment of liver diseases characterized by excessive apoptosis. This drug is a first-in-class anti-apoptotic caspase inhibitor with demonstrated preliminary efficacy in liver-impaired patients in humans.

AstraZeneca (formerly Astra) is developing robalzotan (NAD-299, AZD-7371), a 5-HT1A antagonist, for the potential treatment of depression and anxiety. The compound has entered phase II trials but was discontinued. Then it investigated for the treatment of irritable bowel syndrome, but the study was prematurely terminated. The same final has expected the development of robalzotan in phase II to treat overactive bladder, this investigation was terminated in July 2005.

Sonolisib (PX-866) is a small-molecule inhibitor of the alpha, gamma, and delta isoforms of phosphoinositide 3-kinase (PI3K) with potential antineoplastic activity. Sonolisib inhibits the production of the secondary messenger phosphatidylinositol-3,4,5-trisphosphate (PIP3) and activation of the PI3K/Akt signaling pathway, which may result in inhibition of tumor cell growth and survival in susceptible tumor cell populations. Inhibition of the PI3K pathway with Sonolisib leads to inhibition of cell growth and decreased activation of downstream targets in GBM, both in vitro and in vivo, using U87–tumor-bearing mice, including Akt, S6, and mTOR. Sonolisib was in phase II clinical trials by Oncothyreon for the treatment of glioblastoma multiforme and castration-resistant prostate cancer (CRPC). It was in phase I/II clinical trials for the treatment of malignant melanoma, non-small cell lung cancer and Head and neck cancer. In clinical trials, Sonolisib was well tolerated, with common side effects being diarrhea, nausea, vomiting, and elevated liver enzymes. However, no recent development has been reported.

Cidoxepin is the cis-isomer of the widely prescribed tricyclic compound doxepin. Commercial preparations of the tricyclic anti-depressant doxepin contain 15% of the more active cis-doxepin and 85% of the trans-isomer. Elorac, Inc., a rapidly growing specialty pharmaceutical company focused on the treatment of dermatological disorders, is pleased to announce that it has acquired worldwide rights to the active agent Cidoxepin from Gideon Pharmaceuticals. Cidoxepin appears to be much more potent than doxepin while having less sedative and cholinergic side effects. Elorac plans to develop oral formulations of the drug to treat urticaria and topical formulations for treatment of atopic and contact dermatitis.

Siramesine is a sigma2 opioid agonist under development by H Lundbeck as a potential treatment for anxiety. In March 1998, the compound was licensed to Forest Laboratories under a strategic alliance. In August 2000, siramesine entered phase II trials. Siramesine has been shown to trigger cell death of cancer cells and to exhibit a potent anticancer activity in vivo. Siramesine triggers cell death through destabilisation of mitochondria, but not lysosomes. Siramesine is a lysosomotropic detergent that induces cytoprotective autophagosome accumulation. Siramesine involves lysosomal leakage and oxidative stress.

Mocetinostat is an rationally designed, orally available, Class 1-selective, small molecule, 2-aminobenzamide HDAC inhibitor with potential antineoplastic activity. Mocetinostat binds to and inhibits Class 1 isoforms of HDAC, specifically HDAC 1, 2 and 3, which may result in epigenetic changes in tumor cells and so tumor cell death; although the exact mechanism has yet to be defined, tumor cell death may occur through the induction of apoptosis, differentiation, cell cycle arrest, inhibition of DNA repair, upregulation of tumor suppressors, down regulation of growth factors, oxidative stress, and autophagy, among others. It is undergoing clinical trials for treatment of various cancers including bladder cancer, diffuse large B cell lymphoma, follicular lymphoma, myelodysplastic syndromes, non-small cell lung cancer. Fatigue, weight loss or anorexia were most common treatment-related adverse events.

Zaurategrast (CDP323) is an ethyl ester prodrug of CT7758, a potent carboxylic acid antagonist of integrin alpha4-beta1 (α4β1) or very late antigen 4 (VLA4). CDP323 was under development with UCB and Biogen Idec for the treatment of multiple sclerosis. Its development was discontinued in 2009 based on inadequate interim efficacy data in a phase II clinical trial.

Traxoprodil (CP-101,606) is a potent, selective N-Methyl-D-aspartate (NMDA) receptor (NR2B subunit) antagonist under development by Pfizer for its potential as a neuroprotectant in head injury and neurodegenerative disease. It is in phase II trials in the US and in phase I in Japan for the potential treatment of head injury, such as, Depressive Disorder, Major and Parkinson's Disease. CP-101,606 does not protect against glutamate-induced neurotoxicity in cultured cerebellar neurons, up to a dose of 10 uM. These results are consistent with CP-101,606 being a potent NMDA antagonist, selective for the type of NMDA receptor associated with the hippocampus. Some further investigation revealed that CP-101,606 was associated with a dose-related dissociation and amnesia. These results support the hypothesis that glutamate antagonists may be useful antidyskinetic agents. However, future studies will have to determine if the benefits of dyskinesia suppression can be achieved without adverse cognitive effects.

Tozasertib, originally developed as VX-680 by Vertex (Cambridge, MA) and later renamed MK-0457 by Merck (Whitehouse Station, NY), was the first aurora kinase inhibitor to be tested in clinical trials. The drug, a pyrimidine derivative, has affinity for all aurora family members at nanomolar concentrations with inhibitory constant values (Ki(app)) of 0.6, 18, and 4.6 nM for aurora A, aurora B, and aurora C, respectively. Preclinical studies confirmed that tozasertib inhibited both aurora A and aurora B kinase activity, and activity has been reported against prostate, thyroid, ovarian, and oral squamous cancer cell lines. Upon treatment with tozasertib, cells accumulate with a 4N DNA content due to a failure of cytokinesis. This ultimately leads to apoptosis, preferentially in cells with a compromised p53 function. Tozasertib is an anticancer chemotherapeutic pan-aurora kinase (AurK) inhibitor that also inhibits FMS-like tyrosine kinase 3 (FLT3) and Abl. Tozasertib is currently in clinical trials as a potential treatment for acute lymphoblastic leukemia (ALL). In cellular models of cancer, tozasertib activates caspase-3 and PARP and decreases expression of HDAC, increasing apoptosis and inhibiting cell growth. In other cellular models, tozasertib inhibits cell proliferation and metastasis by blocking downstream ERK signaling and downregulating cdc25c and cyclin B. This compound also decreases tumor growth in an in vivo model of prostate cancer.