- The Food and Drug Administration on Tuesday began reviewing an anemia pill from GlaxoSmithKline called daprodustat, the third drug of its kind to reach the U.S. regulator in the past year.
- The FDA already rejected the other two medicines, developed by Akebia and FibroGen, due to concerns that the drugs aren't as safe as currently approved injectable medicines for chronic kidney disease. Unlike the others, however, GSK's drug wasn't associated with an increased risk of heart problems in clinical testing.
- Daprodustat is already approved in Japan under the name Duvroq and is under review in Europe. The FDA has set a decision date of Feb. 1 for the medicine, which is meant to be a more convenient alternative to hemoglobin-boosting drugs like Amgen's Aranesp and Epogen.
GSK is the third company to test the FDA's stance on anemia pills in less than a year. It could face an uphill battle with the agency, which has been tougher on the drug class than other regulators.
Japan, for example, approved all three medicines from GSK, Akebia and FibroGen. Europe's drug regulator cleared FibroGen's last year. Since last August, though, the FDA has sent back the other two anemia pills and demanded more data. Neither FibroGen nor Akebia has committed to running another trial.
GSK's case to the FDA could be different, though. Two large studies published in The New England Journal of Medicine last year showed the drug increased levels of oxygen-carrying hemoglobin in chronic kidney disease patients who either are, or aren't, dependent on dialysis. In both studies, daprodustat didn't perform meaningfully worse than an injectable biologic on measures of heart safety, areas in which both Akebia's and FibroGen's drugs struggled.
The potential financial rewards could be significant for GSK. Lack of access to the U.S. market has curtailed previous blockbuster expectations for anemia pills, and the FDA's rejections have blocked GSK's would-be competitors. GSK estimates the drug's peak sales potential to be between 500 million and 1 billion pounds, or between $650 million and $1.3 billion.
Still, there are other concerns U.S. regulators could flag. For example, an editorial published in the NEJM alongside GSK's two large studies last year noted the company's case isn't as strong in the non-dialysis dependent population — a larger group of patients for whom the benefits of treatment are less certain. The author, a nephrologist at the Memorial University of Newfoundland named Patrick Parfrey, also noted the drug's mechanism of action could pose a cancer risk. GSK did see higher rates of cancer-related death, tumor progression or recurrence among those on its drug instead of an injectable biologic.
While results are promising in patients who need dialysis, "questions about indications and safety warrant further investigation" in those who aren't on dialysis, Parfrey wrote.