Andexanet alfa

Andexanet alfa
Clinical data
Trade names	Andexxa, Ondexxya, others
Other names	Coagulation factor Xa (recombinant), inactivated-zhzo, PRT06445, r-Antidote, PRT4445
AHFS/Drugs.com	Monograph
License data	US DailyMed: Andexanet_alfa;
Pregnancy; category	AU: B2; ;
Routes of; administration	Intravenous injection
ATC code	V03AB38 (WHO) ;
Legal status
Legal status	AU: S4 (Prescription only); CA: ℞-only / Schedule D; UK: POM (Prescription only); US: ℞-only; EU: Rx-only;
Pharmacokinetic data
Elimination half-life	5 h to 7 h
Identifiers
	IUPAC name Andexanet alfa;
CAS Number	1262449-58-0;
IUPHAR/BPS	7576;
DrugBank	DB14562;
ChemSpider	none;
UNII	BI009E452R;
KEGG	D11029;
ChEMBL	ChEMBL3301583;

Andexanet alfa, sold under the brand name Andexxa among others, is an antidote for the medications rivaroxaban and apixaban, when reversal of anticoagulation is needed due to uncontrolled bleeding. It has not been found to be useful for other factor Xa inhibitors. It is given by injection into a vein.

Common side effects include pneumonia and urinary tract infections. Severe side effects may include blood clots, heart attacks, strokes, or cardiac arrest. It works by binding to rivaroxaban and apixaban.

It was approved for medical use in the United States in May 2018. It was developed by Portola Pharmaceuticals.

In December 2025, the FDA issued a drug safety communication in response to postmarketing safety data on thromboembolic events, including serious and fatal outcomes, and determined that the risks of the medication outweigh the benefits. In response, AstraZeneca submitted a request to voluntarily withdraw the Biologics License Application and end commercial sales and manufacturing in the United States by December 22, 2025.