Cara possesses best-in-class peripherally-selective molecules that interact with kappa opioid receptors present on peripheral, pain-sensing nerves. These compounds exhibit potent analgesic and anti-inflammatory properties in animals. Unlike currently marketed opioids, these new compounds do not produce inhibition of intestinal transit (ileus), do not induce life-threatening respiratory depression, nor do they elicit signs of addiction or euphoria in animal models.

The degree of kappa receptor selectivity displayed by CR845 ranks as best-in-class compared to all other previously developed compounds for this therapeutic target. Moreover, CR845 displayed no significant affinity for any other non-opioid known receptors.