GSK620 is a potent and orally active pan-BD2 inhibitor with excellent broad selectivity, developability and in vivo oral pharmacokinetics. GSK620 is highly selective for the BET-BD2 family of proteins, with >200-fold selectivity over all other bromodomains. GSK620 shows an anti-inflammatory phenotype in human whole blood[1].

GSK620 shows an anti-inflammatory phenotype in human whole blood. Human blood samples are stimulated with LPS, which produces a strong immune response. The monocyte chemattractant protein 1 (MCP-1/CCL2) is measured. This is a chemokine which recruits monocytes, memory T cells, and dendritic cells to sites of inflammation. GSK620 reduces the MCP-1 response in a concentration-dependent manner with (an expected) ∼1 log drop off in potency relative to the biochemical BRD4 BD2 potencies observed[1].

Highlighting the utility of GSK620 as an in vivo tool, efficacy is observed in separate models of inflammatory arthritis, psoriasis, and hepatitis[1].

[1]. Seal JT, et al. The Optimization of a Novel, Weak Bromo and Extra Terminal Domain (BET) Bromodomain Fragment Ligand to a Potent and Selective Second Bromodomain (BD2) Inhibitor. J Med Chem. 2020;63(17):9093-9126.