AstraZeneca, FibroGen's roxadustat hits snag at FDA, but analysts figure an approval's still on its way

Partners AstraZeneca and FibroGen had been hoping for a 2020 approval for their blockbuster-to-be anemia drug roxadustat in the U.S., but that's not going to happen. 

The FDA pushed its decision deadline to March 20—from December 20—to review “further clarifying analyses of clinical data," AstraZeneca said Friday. The companies say they plan to submit the analyses as soon as possible. 

Roxadustat is under FDA review as an oral medicine to treat anemia caused by chronic kidney disease, both in patients who need dialysis and those who don't.

AstraZeneca partnered with FibroGen to develop and market the drug back in 2013 with a $350 million payment up front, and up to $465 million in milestones. Roxadustat is already approved in China to treat nondialysis- and dialysis-dependent renal anemia. In Japan, the medicine is marketed by Astellas as Evrenzo in dialysis and nondialysis patients.

Analysts have big expectations for the drug as the companies work to clear the FDA's hurdles. EvaluatePharma has predicted the drug could generate $1.488 billion by 2024, while the team at SVB Leerink has said the medicine could turn in more than twice that much, forecasting $3 billion to $3.5 billion that year.

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On Monday, analysts with Mizuho wrote that the FDA delay is “immaterial” to FibroGen’s overall valuation. The FDA is restricted to making such changes to applications only for “approvable” drugs, they wrote, so the details provided by the companies offer good signs for the med’s approvability. 

“We believe that the delay has a positive read-through to approvability; our confidence is bolstered by precedent cases of the FDA extending PDUFA dates and ultimately approving the delayed applications,” Mizuho analysts wrote. 

FibroGen CEO Enrique Conterno said in a statement there’s “significant unmet medical need for the treatment of anemia of CKD, and we are committed to bringing roxadustat to patients in the U.S. as soon as possible.” As a hypoxia-inducible factor prolyl hydroxylase inhibitor, Roxadustat is the first drug in its class to be under FDA review for anemia of chronic kidney disease. 

RELATED: Akebia crashes on vadadustat flop in larger anemia indication. Will AZ, FibroGen own the market? 

Aside from roxadustat, other medicines in the class in development include GlaxoSmithKline’s daprodustat and Akebia Therapeutics’ vadudastat. The latter medicine recently failed a phase 3 trial in nondialysis-dependent CKD patients, providing a boost to the AZ and FibroGen drug, analysts wrote.