Subsequent Event	6 Months Ended
Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Event	11.Subsequent Event Outcome of FDA Advisory Committee Review On July 15, 2021, the FDA CRDAC voted to recommend not approving roxadustat for the treatment of anemia due to CKD in adult patients. While the FDA is not required to follow the CRDAC’s vote, the agency considers the CRDAC’s non-binding recommendations when making its decision. The Company evaluated this subsequent event and concluded that it required adjustment and disclosure in the condensed consolidated financial statements, specifically to the drug product revenue related the bulk drug product shipments to AstraZeneca as commercial supply under the terms of the Master Supply Agreement. As a result, the Company recorded $11.2 million as deferred revenue as of June 30, 2021. See Note 2, Collaboration Agreements and Revenues, for details. License Agreement with Eluminex On July 19, 2021, Eluminex Biosciences (Suzhou) Limited (“Eluminex”), an ophthalmology-focused biotechnology company headquartered in Suzhou, China with a US-subsidiary office in San Francisco Bay Area, California, exclusively licensed global rights from FibroGen, Inc. for the development and commercialization of an investigational biosynthetic cornea derived from recombinant human collagen Type III intended to treat patients with corneal blindness. Under the terms of the agreement, Eluminex will make an $8 million upfront payment to FibroGen. In addition, FibroGen may receive up to a total of $64 million in future manufacturing, clinical, regulatory, and commercial milestone payments for the biosynthetic cornea program, as well as $36 million in commercial milestones for the first recombinant collagen III product that is not the biosynthetic cornea. FibroGen will also be eligible to receive mid single-digit to low double-digit royalties based upon worldwide net sales of cornea products, and low single-digit to mid single-digit royalties based upon worldwide net sales of other recombinant human collagen type III products that are not cornea products.

Subsequent Event

6 Months Ended

Jun. 30, 2021

11.Subsequent Event

Outcome of FDA Advisory Committee Review

On July 15, 2021, the FDA CRDAC voted to recommend not approving roxadustat for the treatment of anemia due to CKD in adult patients. While the FDA is not required to follow the CRDAC’s vote, the agency considers the CRDAC’s non-binding recommendations when making its decision.

The Company evaluated this subsequent event and concluded that it required adjustment and disclosure in the condensed consolidated financial statements, specifically to the drug product revenue related the bulk drug product shipments to AstraZeneca as commercial supply under the terms of the Master Supply Agreement. As a result, the Company recorded $11.2 million as deferred revenue as of June 30, 2021. See Note 2, Collaboration Agreements and Revenues, for details.

License Agreement with Eluminex

On July 19, 2021, Eluminex Biosciences (Suzhou) Limited (“Eluminex”), an ophthalmology-focused biotechnology company headquartered in Suzhou, China with a US-subsidiary office in San Francisco Bay Area, California, exclusively licensed global rights from FibroGen, Inc. for the development and commercialization of an investigational biosynthetic cornea derived from recombinant human collagen Type III intended to treat patients with corneal blindness.

Under the terms of the agreement, Eluminex will make an $8 million upfront payment to FibroGen. In addition, FibroGen may receive up to a total of $64 million in future manufacturing, clinical, regulatory, and commercial milestone payments for the biosynthetic cornea program, as well as $36 million in commercial milestones for the first recombinant collagen III product that is not the biosynthetic cornea. FibroGen will also be eligible to receive mid single-digit to low double-digit royalties based upon worldwide net sales of cornea products, and low single-digit to mid single-digit royalties based upon worldwide net sales of other recombinant human collagen type III products that are not cornea products.