By Michael Dabaie

FibroGen Inc. shares were down 14% to $37.66 in late morning trading.

The company said after the market close Friday that the Food and Drug Administration extended the review period of the new drug application for roxadustat for the treatment of anemia of chronic kidney disease by three months.

The updated Prescription Drug User Fee Act action date is March 20, 2021, the company said.

FibroGen said the FDA is close to finalizing its review of the NDA. FibroGen is submitting additional analyses of existing roxadustat clinical data, which require an extension of the original PDUFA date.

"FibroGen is working closely with the FDA, in collaboration with our partner, AstraZeneca, to support the final review of the new drug application for roxadustat," said FibroGen Chief Executive Enrique Conterno.

AstraZeneca and FibroGen "are committed to working with the FDA and have agreed to submit the additional clarifying analyses as soon as possible to assist with the completion of labelling discussions," AstraZeneca said.

"While there are numerous explanations for the PDUFA delay, none of them are good (especially considering how late it came in the review cycle)," Raymond James said in a note dated Friday. The firm maintained the stock at underperform.

"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 Securities USA said in an analyst note.

Mizuho said it reaffirmed its buy rating and $72 price target. The firm said it "would buy shares on weakness if the market opens lower Monday morning."

Stifel said it reiterates its buy rating on FibroGen shares and $70 target price. "Following FDA's late request for additional analysis of already-existing roxadustat data to complete NDA review, FibroGen's submission will be considered a 'major amendment', consequently extending the PDUFA date," Stifel said

"Ultimately, we believe a request for additional analysis [as opposed to a complete response letter] suggests FDA is leaning towards roxa approval in 1Q21," Stifel said.

Write to Michael Dabaie at michael.dabaie@wsj.com

(END) Dow Jones Newswires

12-21-20 1210ET