Tozadenant

Tozadenant
Clinical data
Other names	RO4494351; RO-4494351; SYN-115; SYN115
Routes of; administration	Oral
Drug class	Adenosine A2A receptor antagonist; Antiparkinsonian agent
ATC code	None;
Pharmacokinetic data
Elimination half-life	15 hours
Identifiers
	IUPAC name 4-hydroxy-N-(4-methoxy-7-morpholin-4-yl-1,3-benzothiazol-2-yl)-4-methylpiperidine-1-carboxamide;
CAS Number	870070-55-6;
PubChem CID	11618368;
IUPHAR/BPS	5611;
DrugBank	DB12203;
ChemSpider	9793117;
UNII	D9K857J81I;
KEGG	D10174;
ChEBI	CHEBI:177494;
ChEMBL	ChEMBL2105747;
PDB ligand	9XW (PDBe, RCSB PDB);
Chemical and physical data
Formula	C19H26N4O4S
Molar mass	406.50 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CC1(CCN(CC1)C(=O)NC2=NC3=C(C=CC(=C3S2)N4CCOCC4)OC)O;
	InChI InChI=1S/C19H26N4O4S/c1-19(25)5-7-23(8-6-19)18(24)21-17-20-15-14(26-2)4-3-13(16(15)28-17)22-9-11-27-12-10-22/h3-4,25H,5-12H2,1-2H3,(H,20,21,24); Key:XNBRWUQWSKXMPW-UHFFFAOYSA-N;

Tozadenant (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name; developmental code names RO4494351 and SYN-115) is an adenosine A_2A receptor antagonist which was under development for the treatment of Parkinson's disease and liver disorders but was never marketed due to safety concerns.^[1]^[3] It is taken orally.^[1] Tozadenant was under development by Roche, Acorda Therapeutics, and Biotie Therapies.^[1] It reached phase 3 clinical trials for Parkinson's disease prior to the discontinuation of its development.^[1] The development of tozadenant was discontinued due to findings of agranulocytosis and associated serious adverse effects in clinical trials including five patient deaths.^[1]^[4]^[5]

References

^ ^a ^b ^c ^d ^e ^f "Acorda Therapeutics". AdisInsight. 5 November 2023. Retrieved 28 January 2026.
^ Mancel V, Mathy FX, Boulanger P, English S, Croft M, Kenney C, et al. (August 2017). "Pharmacokinetics and metabolism of [¹⁴C]-tozadenant (SYN-115), a novel A2a receptor antagonist ligand, in healthy volunteers". Xenobiotica; the Fate of Foreign Compounds in Biological Systems. 47 (8): 705–718. doi:10.1080/00498254.2016.1221164. PMID 27489076.
^ Perez-Lloret S, Merello M (June 2014). "Two new adenosine receptor antagonists for the treatment of Parkinson's disease: istradefylline versus tozadenant". Expert Opinion on Pharmacotherapy. 15 (8): 1097–1107. doi:10.1517/14656566.2014.903924. PMID 24673462.
^ Taylor P (15 November 2017). "Acorda slumps on safety fears for Parkinson's drug tozadenant". Fierce Biotech. Retrieved 28 January 2026.
^ Taylor NP (20 November 2017). "Acorda dumps $363M Parkinson's drug after patient deaths". Fierce Biotech. Retrieved 28 January 2026.