Cara has completed a clinical Phase 1a trial for its lead peripheral kappa agonist, CR665. This single-center trial evaluated the safety, tolerability, pharmacokinetic profile, and pharmacological activity of CR665 in a double-blind, randomized, placebo-controlled, single escalating intravenous dose study in 60 healthy male and female volunteers. CR665 was shown to be safe at all doses investigated, with no apparent gender differences, and no reports of serious side effects or adverse central nervous system activity. Cara subsequently plans to test the effectiveness of intravenous CR665 on postoperative pain by assessing its acute efficacy against both somatic pain and visceral pain. The company has signed a license agreement with J&J / Alza for the further development of CR665.