March 27 (Reuters) - The U.S. Food and Drug Administration approved Akebia Therapeutics' drug, vadadustat, to treat anemia caused by chronic kidney disease (CKD) in dialysis patients, the drugmaker said on Wednesday.

The drug will be available under the brand name Vafseo, it added.

The FDA had earlier declined to approve vadadustat - a Hypoxia-inducible factor–prolyl hydroxylase (HIF-PH) inhibitor - on safety concerns, as it posed an increased risk of blood clot formations and drug-induced injuries to the liver.

The regulator indicated in its letter that Akebia could explore conducting new studies to potentially show a favorable benefit-risk assessment of the drug.

Other HIF-PH inhibitor approved by the health regulator include GlaxoSmithKline's daprodustat, which helped improve haemoglobin levels in late-stage trials, according to data released in July 2021.

HIF-PH inhibitors are a class of oral drugs designed to boost production of red blood cells by mimicking the body's response at high altitudes.

Akebia's vadadustat is currently approved in 37 countries. It is approved in Europe, Australia and Taiwan for the treatment of symptomatic anemia due to CKD in adult patients on chronic maintenance dialysis.

In Japan, vadadustat is approved as a treatment for anemia due to CKD in both dialysis-dependent and non-dialysis dependent adult patients.

H.C. Wainwright analyst Ed Arce estimates the drug's launch in second half of this year, with peak sales of $954 million in 2031.

Anemia, or the low count of red blood cells, is a common complication of CKD, a condition in which a person's kidneys cannot filter blood efficiently, causing waste and fluid to build up in the body.

According to Centers for Disease Prevention and Control, about 35.5 million adults in the United States are estimated to have CKD. (Reporting by Pratik Jain, Vaibhav Sadhamta and Mrinmay Dey in Bengaluru; Editing by Subhranshu Sahu and Rashmi Aich)