Difelikefalin

Difelikefalin
Clinical data
Trade names	Korsuva
Other names	CR845, FE-202845, D-Phe-D-Phe-D-Leu-D-Lys-[γ-(4-N-piperidinyl)amino carboxylic acid]
License data	US DailyMed: Difelikefalin;
Pregnancy; category	AU: B1;
Routes of; administration	Intravenous
Drug class	Kappa opioid receptor agonist
ATC code	V03AX04 (WHO) ;
Legal status
Legal status	AU: S4 (Prescription only); CA: ℞-only; US: ℞-only; EU: Rx-only;
Pharmacokinetic data
Bioavailability	100% (IV)
Metabolism	Not metabolized
Elimination half-life	2 hours
Excretion	Excreted as unchanged; drug via bile and urine
Identifiers
	IUPAC name 4-amino-1-[(2R)-6-amino-2-[[(2R)-2-[[(2R)-2-[[(2R)-2-amino-3-phenylpropanoyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]piperidine-4-carboxylic acid;
CAS Number	1024828-77-0; as salt: 1024829-44-4;
PubChem CID	24794466; as salt: 91864509;
DrugBank	DB11938; as salt: DBSALT003191;
ChemSpider	44208824;
UNII	NA1U919MRO; as salt: 0P70AR5BYB;
KEGG	D11111; as salt: D10890;
ChEMBL	ChEMBL3989915;
CompTox Dashboard (EPA)	DTXSID401032896 ;
Chemical and physical data
Formula	C36H53N7O6
Molar mass	679.863 g·mol−1
3D model (JSmol)	Interactive image; as salt: Interactive image;
	SMILES CC(C)C[C@H](C(=O)N[C@H](CCCCN)C(=O)N1CCC(CC1)(C(=O)O)N)NC(=O)[C@@H](CC2=CC=CC=C2)NC(=O)[C@@H](CC3=CC=CC=C3)N; ; as salt: CC(O)=O.CC(C)C[C@@H](NC(=O)[C@@H](CC1=CC=CC=C1)NC(=O)[C@H](N)CC1=CC=CC=C1)C(=O)N[C@H](CCCCN)C(=O)N1CCC(N)(CC1)C(O)=O;
	InChI InChI=1S/C36H53N7O6/c1-24(2)21-29(32(45)40-28(15-9-10-18-37)34(47)43-19-16-36(39,17-20-43)35(48)49)42-33(46)30(23-26-13-7-4-8-14-26)41-31(44)27(38)22-25-11-5-3-6-12-25/h3-8,11-14,24,27-30H,9-10,15-23,37-39H2,1-2H3,(H,40,45)(H,41,44)(H,42,46)(H,48,49)/t27-,28-,29-,30-/m1/s1; Key:FWMNVWWHGCHHJJ-SKKKGAJSSA-N; ; as salt: InChI=1S/C36H53N7O6.C2H4O2/c1-24(2)21-29(32(45)40-28(15-9-10-18-37)34(47)43-19-16-36(39,17-20-43)35(48)49)42-33(46)30(23-26-13-7-4-8-14-26)41-31(44)27(38)22-25-11-5-3-6-12-25;1-2(3)4/h3-8,11-14,24,27-30H,9-10,15-23,37-39H2,1-2H3,(H,40,45)(H,41,44)(H,42,46)(H,48,49);1H3,(H,3,4)/t27-,28-,29-,30-;/m1./s1; Key:MZWHRPKAHCWTOI-KGURMGBCSA-N;

Difelikefalin, sold under the brand name Korsuva, is an opioid peptide used for the treatment of moderate to severe itch. It acts as a peripherally-restricted, highly selective agonist of the κ-opioid receptor (KOR).

Difelikefalin acts as an analgesic by activating KORs on peripheral nerve terminals and KORs expressed by certain immune system cells. Activation of KORs on peripheral nerve terminals results in the inhibition of ion channels responsible for afferent nerve activity, causing reduced transmission of pain signals, while activation of KORs expressed by immune system cells results in reduced release of proinflammatory, nerve-sensitizing mediators (e.g., prostaglandins).

Difelikefalin was approved for medical use in the United States in August 2021. The U.S. Food and Drug Administration considers it to be a first-in-class medication.