TNF-α antagonist is an exocyclic peptide that mimics the critical TNF-α recognition loop on TNF receptor I complex and, thus, prevents ligand interaction with the receptor. By blocking the TNF receptor ligand contact site, this peptide interferes with both activating receptor activator of NF-κB (RANK) and TNF-α's recruitment and activation of osteoclasts. TNF-α antagonist has been used to block bone resorption in the study of systemic bone loss in rheumatoid arthritis and inflammatory bone destruction.
MF-592 is a potent and selective antagonists of the EP4 receptor. MF-592 demonstrated good functional potency (hEP4 IC50 = 3 nM) and potent inhibition of PGE2 modulated TNFa release in LPS stimulated human whole blood (hWB) (IC50 = 78nM). In addition, it showed an excellent oral pharmacokinetic (PK) profile and in vivo efficacy in a rat chronic adjuvant-induced-arthritis model (ED50 = 0.1 mg kg day).. MF-592 has a desirable overall preclinical profile that suggests it is suitable for further development.