Fostamatinib

Fostamatinib
Clinical data
Trade names	Tavalisse, Tavlesse
Other names	Fostamatinib disodium hexahydrate, tamatinib fosdium, R-788, NSC-745942, R-935788
AHFS/Drugs.com	Monograph
MedlinePlus	a618025
License data	EU EMA: by INN; US DailyMed: Fostamatinib;
Pregnancy; category	Not recommended;
Routes of; administration	By mouth
ATC code	B02BX09 (WHO) ;
Legal status
Legal status	CA: ℞-only; US: ℞-only; EU: Rx-only; In general: ℞ (Prescription only);
Pharmacokinetic data
Bioavailability	55% (tamatinib metabolite)
Protein binding	98% (tamatinib metabolite)
Metabolism	Gut (ALP to tamatinib); Liver (tamatinib metabolite by CYP3A4, UGT1A9)
Elimination half-life	15 hours
Excretion	faecal (80%), urine (20%)
Identifiers
	IUPAC name [6-({5-Fluoro-2-[(3,4,5-trimethoxyphenyl)amino]-4-pyrimidinyl}amino)-2,2-dimethyl-3-oxo-2,3-dihydro-4H-pyrido[3,2-b][1,4]oxazin-4-yl]methyl dihydrogen phosphate;
CAS Number	901119-35-5 [PubChem];
PubChem CID	11671467;
IUPHAR/BPS	7796;
DrugBank	DB12010 ;
ChemSpider	9846198 ;
UNII	SQ8A3S5101;
KEGG	D09347; as salt: D09348;
ChEMBL	ChEMBL2103830;
CompTox Dashboard (EPA)	DTXSID401009170 ;
ECHA InfoCard	100.125.771
Chemical and physical data
Formula	C23H26FN6O9P
Molar mass	580.466 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES Fc1cnc(nc1Nc2nc3N(C(=O)C(Oc3cc2)(C)C)COP(=O)(O)O)Nc4cc(OC)c(OC)c(OC)c4;
	InChI InChI=1S/C23H26FN6O9P/c1-23(2)21(31)30(11-38-40(32,33)34)20-14(39-23)6-7-17(28-20)27-19-13(24)10-25-22(29-19)26-12-8-15(35-3)18(37-5)16(9-12)36-4/h6-10H,11H2,1-5H3,(H2,32,33,34)(H2,25,26,27,28,29) ;

Fostamatinib, sold under the brand names Tavalisse and Tavlesse, is a tyrosine kinase inhibitor medication for the treatment of chronic immune thrombocytopenia (ITP). The drug is administered by mouth.

Fostamatinib blocks the activity of the enzyme spleen tyrosine kinase (SYK). This enzyme is involved in stimulating parts of the immune system. By blocking SYK's activity, fostamatinib reduces the immune system's destruction of platelets, so allowing the platelet count to rise, which reduces the likelihood of excessive bleeding.

The most commonly reported side effects are diarrhea, high blood pressure, nausea, respiratory infection, dizziness, increased liver enzymes, rash, abdominal pain, fatigue, chest pain and decreased white blood cell count.

The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.