Cara’s pain killer proves safe

The phase I clinical trial for Cara’s peripherally acting kappa opioid agonist, CR665, demonstrate the treatment to be safe and well-tolerated following intravenous infusion. Furthermore, the resulting plasma levels of CR665 are expected to be associated with analgesic activity.

The placebo-controlled study tested the safety of the drug in 60 healthy male and female volunteers. The pharmacological activity of CR665 at peripheral kappa receptors was confirmed utilizing a quantitative endocrine biomarker, which demonstrated receptor activation at relatively low doses of the drug candidate.

“We are extremely pleased with the outcome of our trial. These preliminary results are consistent with CR665’s peripheral mechanism of action,” stated Dr Frederique Menzaghi, Cara’s vice president of R&D. “The results have not only confirmed our expectations in relation to the safety of CR665 but have also provided evidence of kappa receptor activation at much lower drug doses than predicted from preclinical animal studies.”

CR665 is the lead clinical development candidate from a series of highly selective peripheral kappa opioid receptor agonists. In preclinical studies, CR665 was highly selective for the peripheral kappa opioid receptor.

Preclinical animal studies suggest that CR665 is a potent analgesic compound. In addition, unlike currently marketed opioids, CR665 does not produce inhibition of intestinal transit (ileus), induce respiratory depression, or elicit signs of addiction in animal models. Preclinical studies also indicate that CR665 possesses anti-inflammatory activities.