[ * ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities and Exchange
Commission pursuant to Rule 24b-2 of the Securities Act of 1934, as amended.

Exhibit 10.8

June 15, 2018

Astellas Pharma, Inc.

2-5-1, Nihonbashi-Honcho, Chuo-ku
Tokyo 103-8411, Japan

Attn.: Mr. Nobuyuki Tanaka

Vice President, Supply Chain Management, Pharmaceutical Technology

Subject:   API Batch Transfer Price Prior to Issuance of Listed Price

Dear Mr. Tanaka,

FibroGen, Inc. and Astellas Pharma, Inc. (collectively the “Parties”) are
negotiating in good faith an amendment (the “Amendment”) to the Collaboration
Agreement (the “Agreement”), effective as of June 1, 2005, by and between the
Parties, intended to allow Astellas to manufacture Lead Compound formulated as
bulk drug product (“Astellas Bulk Product”) for its development and commercial
activities in the Japan territory.

To enable timely conduct of process validation activities by Astellas, FibroGen
is in good faith transferring to Astellas a batch of FG-4592 formulated as drug
substance (the “API Batch”) pursuant to the terms of a Material Transfer
Agreement Letter dated June 15, 2018 (the “MTA”).

This letter serves to confirm the agreement of the Parties that the Transfer
Price for the API Batch, and any other FG-4592 formulated as drug substance for
[*] supplied by FibroGen to Astellas prior to the issuance of Listed Price (the
“API Batch Transfer Price”) shall be:

$[*] per kg of roxadustat API

Payment shall be [*], which shall be paid by Astellas to FG no later than [*]
days after the date of invoice, which invoice FG shall deliver to Astellas upon
Delivery of API Batches to Astellas pursuant to applicable terms under the
Agreement.  

This payment is subject to a [*], as set forth in Section 9.2(a) of the
Agreement, pursuant to which [*], as the case may be, of the [*] due under the
Agreement as amended by the Amendment, [*].

Please confirm Astellas’ agreement by signing below in the indicated, and return
to us the executed document in a .pdf format.  Should you have any questions
please let me know.

Sincerely,

/s/ Kirara Tsuboi

Kirara Tsuboi

Vice President, Business Development

FibroGen, Inc.

 

AGREED AND ACKNOWLEDGED:

/s/ Nobuyuki Tanaka

Nobuyuki Tanaka

Vice President, Supply Chain Management, Pharmaceutical Technology

Astellas Pharma, Inc.