E-52862

E-52862, also known as sigma-1 receptor antagonist (S1A, S1RA), as well as MR-309, is a selective sigma-1 receptor antagonist, with a reported binding affinity of K_i = 17.0 ± 7.0 nM, selective over the sigma-2 receptor and against a panel of other 170 receptors, enzymes, transporters and ion channels.^[1][2] In preclinical studies, S1RA has demonstrated efficacy in relieving neuropathic pain and pain in other sensitizing conditions, associated with an improvement of the emotional negative state.^[2][3][4][5]

E-52862

Clinical data
Other names	S1A; S1RA; MR-309
Identifiers
IUPAC name 4-(2-((5-methyl-1-(naphthalen-2-yl)-1H-pyrazol-3-yl)oxy)ethyl)morpholine
CAS Number	878141-96-9
ChemSpider	28641653
UNII	ZW18DSD1H4
ChEMBL	ChEMBL2170062
CompTox Dashboard (EPA)	DTXSID901022521
Chemical and physical data
Formula	C20H23N3O2
Molar mass	337.423 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC1=CC(OCCN2CCOCC2)=NN1C1=CC=C2C=CC=CC2=C1
InChI InChI=1S/C20H23N3O2/c1-16-14-20(25-13-10-22-8-11-24-12-9-22)21-23(16)19-7-6-17-4-2-3-5-18(17)15-19/h2-7,14-15H,8-13H2,1H3 Key:DGPGXHRHNRYVDH-UHFFFAOYSA-N

S1RA is being developed by Esteve for the treatment of neuropathic pain and the potentiation of opioid analgesia and has successfully completed Phase I clinical trials showing good safety and tolerability, and a pharmacokinetic profile compatible with once a day oral administration.^[6] Phase II clinical trials are currently underway, making S1RA the first selective sigma-1 receptor antagonist evaluated in humans for these conditions.

See also

• List of investigational analgesics