GSK126, a potent, highly selective, S-adenosyl-methionine-competitive, small-molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and markedly inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma. EZH2 inactivation by GSK126 is also effective in killing MM cells and CSCs as a single agent or in combination with bortezomib. Clinical trial of GSK126 in patients with MM may be warranted. GSK126 is undergoing phase I trials for hypermethylation-related cancers. GSK126 is in phase I diffuse large B cell lymphoma and follicular lymphoma. GSK126 inhibits cell migration and angiogenesis in solid tumor cell lines through down-regulation of VEGF-A expression. Thus, it may be considered as a novel anticancer drug candidate for solid tumor.

MK-3281 is a potent and orally bioavailable inhibitor of HCV NS5B polymerase which combined excellent cell-based potency with good pharmacokinetic properties in preclinical species. MK-3281 was efficacious in the chimeric mouse model of HCV infection.

Nitroarginine (LNNA), an analog of L-arginine, is a competitive inhibitor of nitric oxide synthase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. The Kd value (k(off)/k(on)) of bovine brain cNOS for LNNA was 15 nM. In contrast to the potent and slow onset of LNNA inhibition of brain cNOS, LNNA inhibition of inducible mouse macrophage NOS (iNOS) was weaker (Ki = 4.4 uM) and rapidly reversible. Thus, LNNA was a 300-fold more potent inhibitor of bovine brain cNOS than mouse macrophage iNOS. By inhibiting nitric oxide synthase LNNA causes the selective reduction of blood flow to tumor cells. Despite the potential of LNNA to function as an adjuvant in cancer therapies, its poor solubility and stability have hindered the development of an injectable formulation of LNNA that is suitable for human administration.

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.

ETC-159 (ETC-1922159) is an inhibitor of membrane-bound O-acyltransferase porcupine. Porcupine palmitoleates Wnt and this modification is essential for binding to chaperone WLS and Frizzled receptors and is therefore required for the activity of all Wnts. ETC-159 exerts antineoplastic properties both in vitro and in vivo due to inhibition of Wnt pathway. ETC-159 development has progressed to phase I clinical trial.

Cenerimod is an orally available sphingosine-1-phosphate receptor 1 (S1P1) modulator that is being developed by Idorsia Pharmaceuticals for the treatment of systemic lupus erythematosus. Sphingosine-1-phosphate (S1P), a lipid mediator, regulates lymphocyte migration between lymphoid tissue and blood. Cenerimod is a potent, selective, safe and orally administrable S1P1 receptor modulator, which reportedly reduced blood lymphocytes and attenuated murine experimental autoimmune encephalomyelitis (EAE) in a murine model. Cenerimod has potential as novel therapy with an improved safety profile for autoimmune diseases with a high unmet medical need.