Elacridar is an oral bioenhancer that targets multiple drug resistance in tumors. Elacridar is a strong and relatively specific inhibitor of P-gp and BCRP, two main efflux transporters. Development of elacridar is assumed to have been discontinued.

TAK-063 is a highly potent, selective, and orally active phosphodiesterase 10A (PDE10A) inhibitor with IC50 of 0.30 nM; >15000-fold selectivity over other PDEs. TAK-063 is currently being evaluated in clinical trials for the treatment of schizophrenia. Phosphodiesterase 10A (PDE10A) is a cAMP/cGMP phosphodiesterase highly expressed in medium spiny neurons (MSNs) in the striatum. TAK-063 represents a promising drug for the treatment of schizophrenia with potential for superior safety and tolerability profiles.

RRX-001, also known as ABDNAZ, is a dinitroazetidine derivative with potential radiosensitizing activity. Upon administration, RRx-001 is able to dilate blood vessels, thereby increasing tumor blood flow and thus improving oxygenation to the tumor site. By increasing oxygen levels, these tumor cells may be more susceptible to radiation therapy. Tumor hypoxia is correlated with tumor aggressiveness, metastasis and resistance to radiotherapy. In mouse models, RRx-001 administered intravenously as a single agent was equipotent to cisplatin while better tolerated. RRx-001 also showed activity as a radiosensitizer in both in vitro and in vivo models. The activity of RRx-001 is thought to be associated with a nucleophilic substitution by circulating thiol compounds and covalent binding of RRx-001 to cysteinyl residues in Hb, followed by the generation of nitrogen oxides. During 2014-2015 EpicentRx has launched Phase 2 trials in brain, colorectal, non-small cell lung, small cell lung and cholangiocarcinoma both alone and in combination. The anti-proliferative effects of RRx-001 are not explainable via a single mechanism. RRx-001 exerts its anti-proliferative effect, at least partially, through interference with glucose 6 phosphate dehydrogenase (G6PD), a key enzyme in the pentose phosphate pathway, responsible for maintaining adequate levels of the major cellular reductant, NADPH.

2-(4,6-DIMETHYLPYRIMIDIN-2-YL)-5-((2-FLUORO-6-(2H-1,2,3-TRIAZOL-2-YL)PHENYL)CARBONYL)OCTAHYDROPYRROLO(3,4-C)PYRROLE (Seltorexant, MIN 202), a small molecule, selective orexin receptor type-2 antagonist, is being developed by Minerva Neurosciences and Janssen Research & Development for the treatment of insomnia and major depressive disorder. Seltorexant has shown high in vitro affinity (affinity pKi =8.0 and 6.1 for OX2R and OX1R respectively) for the human OX2R and approximates two logs selectivity ratio versus its affinity for the OX1R. Seltorexant demonstrated a dose-dependent normalization of sleep and a trend towards improvement of subjective depressive symptoms in antidepressant-treated MDD patients with residual insomnia. Additionally, seltorexant’s favorable PK profile as a potential sedative-hypnotic drug was confirmed in a MDD population and did not demonstrate unacceptable adverse events or unwanted next-day CNS effects. Seltorexant is in phase II clinical trials for both insomnia and MDD.

Evofosfamide, also formerly known as TH-302, is an investigational hypoxia-activated prodrug and is used to target cancerous cells under hypoxic conditions, which is a feature possessed by multiple solid tumors including glioblastoma and pancreatic cancer. Within regions of tumor hypoxia, evofosfamide releases bromo isophosphoramide mustard (Br-IPM), a potent DNA alkylating agent that kills tumor cells by forming DNA crosslinks. Once activated in hypoxic tissues, Br-IPM can also diffuse into surrounding oxygenated regions of the tumor and kill cells there via a “bystander effect”. Because of its preferential activation in the targeted hypoxic regions of solid tumors, evofosfamide may be less likely to produce broad systemic toxicity seen with untargeted cytotoxic chemotherapies.

Allocupreide is a copper(l) complex used as an antiinflammatory drug and antiarthritic agent. It was used for the treatment of trigeminal neuralgia.

Cinobufotalin, the bufadienolide isolated from toad venom, has displayed antitumor activities in many in vitro systems. It has been shown that cinobufotalin induced significant apoptosis in cultured human lymphoma U-937 cells. It induced DNA fragmentation, mitochondrial membrane potential decrease, and reactive oxygen species (ROS) production in U-937 cells. Cinobufotalin induces cytotoxic effect in cultured lung cancer cells. Cinobufotalin (1/5 mg/kg, i.p. twice daily, for 7 days) significantly inhibited A549 xenograft growth in mice. Further, same cinobufotalin administration improved mice survival at week five. Cinobufotalin administration didn’t significantly affect mice body weight, indicating the relative safety of this regimen. Thus, cinobufotalin inhibits A549 xenograft growth in vivo and improves mice survival.

VLX600 - is a lipophilic cation-based triazinoindolyl-hydrazone compound and mitochondrial oxidative phosphorylation (OxPhos) inhibitor, with potential antineoplastic activity. VLX600 is designed to increase the efficacy of radiotherapy and to kill cancer cells that survive traditional chemotherapy. VLX 600 is a small molecule that inhibits deubiquitinating enzymes USP14 (a ubiquitin thiolesterase) and UCHL5 (a carboxypeptidase). Upon infusion, in normal cells and proliferating tumor cells where glucose is readily available, inhibition of OxPhos by VLX600 induces a hypoxia-inducible factor 1-alpha (HIF-1alpha)-dependent shift to, and an increase in glycolysis. Glycolysis alone does not produce enough energy to support the growth of tumor cells in this environment, and the induction of autophagy occurs. In the metabolically compromised tumor microenvironment, the availability of oxygen and glucose is limited due to poor vascularization and perfusion of tumor micro-areas. Tumor cells growing in this environment are thus unable to compensate for decreased mitochondrial function by increasing glycolysis. This leads to nutrient depletion, decreased energy production, induction of autophagy, tumor cell death and an inhibition of cell proliferation in quiescent tumor cells. Mitochondrial OxPhos, which is hyperactivated in cancer cells, plays a key role in the promotion of cancer cell proliferation. VLX-600 is in phase I clinical trials for the treatment of solid tumours. This compound was originally jointly discovered and developed by Vivolux and Karolinska Institute.

Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. Verinurad specifically inhibits URAT1 with a potency of 25 nM. High affinity inhibition of uric acid transport requires URAT1 residues Cys-32, Ser-35, Phe-365 and Ile-481. Unlike other available uricosuric agents, the requirement for Cys-32 is unique to verinurad. Verinurad doses as low as 2.5 mg produce significant sUA lowering in humans, and this greater reduction in sUA may lead to improved outcomes and medical benefits for patients with gout. Verinurad in monotherapy studies has been associated with increased urinary uric acid concentrations and low rates of serum creatinine (sCr) elevation. Verinurad combined with febuxostat decreased sUA dose-dependently while maintaining uric acid excretion similar to baseline. All dose combinations of verinurad and febuxostat were generally well tolerated.

Novartis Oncology (previously Novartis) is developing nazartinib (formerly EGF 816), a third generation mutant-selective tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR), for the treatment of solid malignancies, with a focus on non-small cell lung cancer. Nazartinib is a covalent mutant-selective EGFR inhibitor, with Ki and Kinact of 31 nM and 0.222 min−1 on EGFR(L858R/790M) mutant, respectively. Upon oral administration, nazartinib covalently binds to and inhibits the activity of mutant forms of EGFR, including the T790M EGFR mutant, thereby preventing EGFR-mediated signaling. This may both induce cell death and inhibit tumor growth in EGFR-overexpressing tumor cells. EGFR, a receptor tyrosine kinase mutated in many tumor cell types, plays a key role in tumor cell proliferation and tumor vascularization. EGF816 preferentially inhibits mutated forms of EGFR including T790M, a secondarily acquired resistance mutation, and may have therapeutic benefits in tumors with T790M-mediated resistance when compared to other EGFR tyrosine kinase inhibitors. As this agent is selective towards mutant forms of EGFR, its toxicity profile may be reduced as compared to non-selective EGFR inhibitors which also inhibit wild-type EGFR.