(Bloomberg) -- GSK Plc’s anemia pill was cleared by US regulators for people with chronic kidney disease who are on dialysis but not for others, downgrading the drug’s revenue potential.  

The medicine will be sold under the name Jesduvroq, the US Food and Drug Administration said in a statement on its website. GSK shares rose as much as 1.2% in London trading.

The drug is a game-changer for patients who currently undergo injections to manage the condition. The FDA decision to follow the advice of a panel and back the treatment only for dialysis patients means it may not turn into a blockbuster as expected. 

The medicine “took on a lower degree of importance after the FDA made it clear that they would not approve the drug in chronic kidney disease patients who are not on dialysis,” said Emily Field, an analyst at Barclays. “The thought was that the non-dialysis patients could be a bigger market.”

Barclays estimates peak sales of just £364 million ($450 million). Analysts at Bloomberg Intelligence say the market opportunity is an estimated $1 billion. 

The FDA’s ruling was probably based on safety concerns observed in the clinical trials, according to analysts at Shore Capital. 

The decision comes after two other medicines for the same indication, one from AstraZeneca Plc and partner FibroGen Inc. and the other from Akebia Therapeutics Inc., failed to get the regulator’s backing. 

More than 700 million people globally suffer from chronic kidney disease, with one in seven estimated to develop anemia, a condition in which the body does not have enough healthy red blood cells. 

GSK is hoping its drug, also known as daprodustat, will be among a new line-up of money-making treatments as it prepares for the loss of a patent on its blockbuster HIV drug dolutegravir later this decade. The company expects clearances on another three medicines this year, including a vaccine against respiratory syncytial virus that has it racing against Pfizer Inc.

--With assistance from Jonathan Roeder.

(Updates with analyst comment in fourth paragraph)

©2023 Bloomberg L.P.