Roxadustat is being developed for patients with chronic kidney disease (CKD) who suffer from anaemia, a condition causing deficiency in red blood cells. This is treated by increasing the production of a hormone that promotes the formation of such cells.
The FTSE 100-listed firm tested patients who are dependent on dialysis (DD) and not dependent (NDD) during phase III trials, with the drug showing efficacy as expected by the market.
However, once the data are submitted to US authorities over the fourth quarter, the focus will shift to the safety of the drug.
The market will hear on Friday whether Roxadustat poses problems to patients at risk of heart conditions, a factor which will change its potential market value if the US authorities demand a specific form of labeling.
Shore Capital said in a note a clean label could bring in up to US$5bn revenues per year, dropping to the current US$1.3bn consensus if the risk is indicated in print.
There is extra pressure in terms of risk for DD patients, as they can already choose between a range of similar and cheaper drugs, meaning Roxadustat will have to look superior or else the needle may move even lower than US$1.3bn.
Anaemia occurs often in patients with CKD, which affects over 200mln patients worldwide, and can have serious effects such as higher risk of hospitalisation, complications and death.
Earlier this year, the drug was approved in China, where the firm has planned a launch for the second half of 2019.