The U.S. Food and Drug Administration approved the first generic versions of Bristol-Myers Squibb Co. and Pfizer Inc.'s blood thinner Eliquis.

The regulator gave the nod to two copies of Eliquis, or apixaban, made by Micro Labs Ltd and Mylan NV, to reduce the risk of stroke and recurrent blockages in the blood vessels due to clots in patients with nonvalvular atrial fibrillation.

Nonvalvular atrial fibrillation is an irregular heart rhythm due to high blood pressure or an overactive thyroid gland, and the cause is not always known. Atrial fibrillation allows blood to pool in the heart and increases the risk of complications like blood clots and strokes.

The Centers for Disease Control and Prevention estimates that between 2.7 million and 6.1 million people in the U.S. have atrial fibrillation, the FDA noted in its Dec. 23 news release.

Bristol-Myers and its partner Pfizer said worldwide sales of Eliquis in the third quarter of 2019 grew 22% year over year to $1.93 billion. Bristol-Myers executives on an Oct. 31 earnings call attributed the growth to demand and volume of prescriptions.