Ritanserin

Ritanserin
Clinical data
Other names	R-55667; R55667; Tiserton
ATC code	None;
Identifiers
	IUPAC name 6-[2-[4-[bis(4-fluorophenyl)methylidene]piperidin-1-yl]ethyl]-7-methyl-[1,3]thiazolo[2,3-b]pyrimidin-5-one;
CAS Number	87051-43-2 ;
PubChem CID	5074;
IUPHAR/BPS	97;
ChemSpider	4896 ;
UNII	145TFV465S;
ChEBI	CHEBI:64195 ;
ChEMBL	ChEMBL267777 ;
CompTox Dashboard (EPA)	DTXSID9042594 ;
ECHA InfoCard	100.163.772
Chemical and physical data
Formula	C27H25F2N3OS
Molar mass	477.57 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CC1=C(C(=O)N2C=CSC2=N1)CCN3CCC(=C(C4=CC=C(C=C4)F)C5=CC=C(C=C5)F)CC3;
	InChI InChI=1S/C27H25F2N3OS/c1-18-24(26(33)32-16-17-34-27(32)30-18)12-15-31-13-10-21(11-14-31)25(19-2-6-22(28)7-3-19)20-4-8-23(29)9-5-20/h2-9,16-17H,10-15H2,1H3 ; Key:JUQLTPCYUFPYKE-UHFFFAOYSA-N ;
	(what is this?) (verify)

Ritanserin, also known by its developmental code name R-55667, is a serotonin antagonist medication described as an anxiolytic, antidepressant, antiparkinsonian agent, and antihypertensive agent. It was chiefly investigated as a drug to treat insomnia, especially to enhance sleep quality by significantly increasing slow wave sleep by virtue of potent and concomitant 5-HT_2A and 5-HT_2C receptor antagonism.

It was never marketed for medical use due to safety problems but is currently used in scientific research.

Some of the safety liabilities that led to its discontinuation for the treatment of insomnia has led to its potential repurposing in the field of oncology. Specifically, ritanserin acts as a potent inhibitor of diacylglycerol kinase alpha (DGKα). As such, it may be used to treat certain types of glioblastoma and melanoma. It has also been used as a reference compound to identify putatively more selective and potent DGKα inhibitors to treat these forms of cancer as well as possibly others.

Additionally, ritanserin blocks c-RAF activation and induces apoptotic cell death of non–small cell lung cancer and small cell lung cancer cells.