[*] = 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 10.28(xxii)

AMENDMENT NO. 20 TO THE PROCESS DEVELOPMENT AND CLINICAL SUPPLY AGREEMENT

THIS AMENDMENT No. 20 (the “Twentieth Amendment”), effective as of June 01, 2015
(the “Twentieth Amendment Effective Date”) by and between Boehringer lngelheim
Biopharmaceuticals GmbH, Binger Str. 173, 55216 Ingelheim, Germany (“BI”) and
FibroGen, Inc., 409 Illinois Street, San Francisco, CA 94158, USA (''FibroGen”),
amends the Process Development and Clinical Supply Agreement entered into by and
between Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397
Biberach an der Riss, Germany (“BI Pharma”) and FibroGen on November 29, 2007,
as amended pursuant to the letter agreements entered into as of June 26, 2008
and August 18, 2008, Amendment No. 1 , effective as of May 28, 2009, Amendment
No. 3, effective as of November 5, 2010, Amendment No. 4, effective as of
January 24, 2011 , Amendment No. 5, effective as of April 15, 2011, Amendment
No. 6, effective as of May 26, 201 I , Amendment No. 7, effective as of January
01, 2012, Amendment No. 8, effective as of July 10, 2012, Amendment No. 9,
effective as of November 26, 2012, Amendment No. 10, effective as of June 21,
2013, Amendment No. 11, effective as of July 9, 2013, Amendment No. 12,
effective as of August 01, 2013 and subsequently assigned by BI Pharma to BI,
Amendment No. 13, effective as of March 06, 2014, Amendment No. 14, effective as
of February 05, 2014, Amendment No. 15, effective as of October 20, 2014,
Amendment No. 16, effective as of December 08, 2014, Amendment No. 17, effective
as of December 08, 2014, Amendment No. 18, effective as of February 15, 2015,
and Amendment 19, effective as of March 01, 2015 (hereinafter together the
“Supply Agreement”). BI and FibroGen shall be referred to individually herein as
a “Party'', and collectively as the “Parties”.

WHEREAS, FibroGen wishes BI to [*] in compliance with the terms of the Supply
Agreement as set forth in and as amended by this Twentieth Amendment. The
activities hereunder will be performed by BI Pharma on behalf of BI.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the Parties agree as follows:

 

(1)

Unless otherwise defined herein, all capitalized terms and phrases used in this
Twentieth Amendment shall have the meaning ascribed to them in the Supply
Agreement.

 

(2)

The Parties agree that pursuant to Section 2.2 of the Supply Agreement, the work
plan entitled [*], Version of March 16, 2015”, attached hereto as Exhibit A, is
hereby added as an amendment to Appendix 2 to the Supply Agreement. Pursuant
thereto BI shall on behalf of FibroGen and in accordance with the Supply
Agreement, [*].

 

(3)

This Twentieth Amendment, together with the Supply Agreement, contains the
entire understanding of the Parties with respect to the subject matter hereof.
Except as otherwise provided herein, the Supply Agreement has not been modified
or amended and remains in full force and effect. All express or implied
agreements and understandings that conflict with the terms of this Twentieth
Amendment, either oral or written, heretofore made with respect to subject
matter herein are expressly superseded by this Twentieth Amendment.

 

(4)

This Twentieth Amendment may be executed in counterparts, each of which shall be
deemed an original, and all of which together shall constitute one and the same
instrument. Counterparts may be signed and delivered by facsimile and/or via
portable document format (pdf) (or similar format), each of which shall be
binding when sent.

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, the Parties have executed this Twentieth Amendment to the
Supply Agreement as of Twentieth Amendment Effective Date.

Biberach, May 11, 2015

BOEHRINGER INGELHEIM BIOPHARMACEUTICALS GMBH

 

ppa.

 

ppa.

 

 

 

[*]

 

[*]

[*]

 

[*]

VP Business & Contracts

 

Head of Legal Germany, Team Biberach

 

 

 

San Francisco, 29 May 2015

 

 

 

 

 

FibroGen, Inc.,

 

 

 

 

 

/s/ Thomas Neff

 

 

Thomas Neff

 

 

CEO

 

 

 

--------------------------------------------------------------------------------

Exhibit A

Work Scope

[*]

(Version of March 16, 2015)

[*]