| IUPAC name
| Other names
CR 665; JNJ 38488502
|3D model (Jmol)||Interactive image|
|Molar mass||671.85 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
CR665 (H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-Picolyl), also known by the previous developmental code names FE-200665 and JNJ-38488502, is an all D-amino acid peptide that acts as a peripherally restricted κ-opioid receptor agonist. The selectivity for FE 200665 is 1/16,900/84,600 for the human κ, μ, and δ opioid receptors, respectively. The dose of FE 200665 required to produce motor impairment (measure of CNS penetration) was 548 times higher than the dose required for antinociceptive activity. It is being developed for use by Cara Therapeutics under the code name CR665.
A small, double blind study was done in healthy humans to determine the analgesic effects. CR665 was dosed at 0.36 mg/kg I.V., and was compared to 15 mg oxycodone orally. CR665 had analgesic effects on visceral pain, but produced a hyperalgesic response in a skin pinch test.
- Vanderah, T. W.; Largent-Milnes, T.; Lai, J.; Porreca, F.; Houghten, R. A.; Menzaghi, F.; Wisniewski, K.; Stalewski, J.; Sueiras-Diaz, J.; Galyean, R.; Schteingart, C.; Junien, J. L.; Trojnar, J.; Rivière, P. J. (2008). "Novel D-Amino Acid Tetrapeptides Produce Potent Antinociception by Selectively Acting at Peripheral κ-Opioid Receptors". European Journal of Pharmacology. 583 (1): 62–72. doi:10.1016/j.ejphar.2008.01.011. PMID 18282565.
- Arendt-Nielsen, L.; Olesen, A. E.; Staahl, C.; Menzaghi, F.; Kell, S.; Wong, G. Y.; Drewes, A. M. (2009). "Analgesic Efficacy of Peripheral κ-Opioid Receptor Agonist CR665 Compared to Oxycodone in a Multi-modal, Multi-Tissue Experimental Human Pain Model: Selective Effect on Visceral Pain". Anesthesiology. 111 (3): 616–624. doi:10.1097/ALN.0b013e3181af6356. PMID 19672186.