N-Arylcinnamides have emerged as potent and important class of TRPV1 antagonists, Compound SB-366791, (fig. 6a) shows competitive and specific activity in both human and rat TRPV1 receptors overall profile of receptor selectivity much better than that of capsazepine.
Within this series of compounds, AMG-9810 (fig. 6b) exhibited high antagonist potency showing good oral bio-availability in rats and a promising pharmacokinetic profile, boding well for clinical efficacy. Another potent blocker from this group is AMG0347(fig. 6c)that was shown in a postoperative pain trial to be able to decrease capsaicin-induced heat and mechanical hyperalgesia and to block central TRPV1 receptors.