KYNTRA BIO, INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant☑

Filed by a Party other than the Registrant☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☑ Definitive Proxy Statement

☐ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

FibroGen, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

☑ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

FIBROGEN, INC.

350 Bay Street

Suite 100 #6009

San Francisco, CA 94133

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To Be Held On June 4, 2025

Dear Stockholder:

You are cordially invited to attend the 2025 Annual Meeting of Stockholders (the “Annual Meeting”) of FibroGen, Inc., a Delaware corporation (also referred to as “we,” “us,” “FibroGen,” and the “Company”). The Annual Meeting will be held via live audio webcast on the internet. You will be able to attend the Annual Meeting online, vote your shares electronically, and submit your questions during the meeting by visitingwww.virtualshareholdermeeting.com/FGEN2025.

The Annual Meeting will be held on Wednesday, June 4, 2025 at 8:00 a.m. Pacific Time for the following purposes:

To elect our Class II director nominee, Jeffrey L. Edwards, to our board of directors to hold office until the 2028 annual meeting of stockholders.

To approve a reverse stock split of the Company’s common stock, including granting our board of directors discretion to determine the final ratio and timing of the reverse stock split.

To approve, on an advisory basis, the compensation of the Company’s named executive officers.

To ratify the selection, by the Audit Committee of our board of directors, of PricewaterhouseCoopers LLP as the independent registered public accounting firm of the Company for the year ending December 31, 2025.

To conduct any other business properly brought before the meeting.

These items of business are more fully described in the proxy statement accompanying this notice.

The record date for the Annual Meeting is April 11, 2025 (the “Record Date”). Only stockholders of record at the close of business on that date may vote by proxy or at the Annual Meeting (live audio webcast) or any adjournment thereof. Please see the attached proxy statement for information on how to vote by proxy and how to attend and vote at the Annual Meeting.

A list of our record stockholders entitled to vote as of the close of business on the Record Date will be available for review for ten days prior to the Annual Meeting at the offices of our corporate counsel Cooley LLP, 3175 Hanover Street, Palo Alto, CA 94304, for any legally valid purpose related to the Annual Meeting, and will be available during the entire time of the Annual Meeting atwww.virtualshareholdermeeting.com/FGEN2025.

Important Notice Regarding the Availability of Proxy Materials for the Annual Stockholders’ Meeting

The proxy statement and Annual Report on Form 10-K

are available atwww.proxyvote.com.

By Order of the Board of Directors

/s/ John Alden

John Alden

Corporate Secretary and General Counsel

San Francisco, California

April 25, 2025

Your vote is very important. Whether or not you expect to attend the Annual Meeting, please vote online or by telephone prior to the Annual Meeting as instructed in these materials, or if you requested and received a proxy by mail, please complete, date, sign, and return the proxy as promptly as possible in order to ensure your representation at the Annual Meeting. Even if you have voted by proxy, you may still vote online if you attend the Annual Meeting. Please review the section below “How do I vote?” for specific instructions on voting your shares before and during the Annual Meeting.

Table of Contents

FIBROGEN, INC.

350 Bay Street

Suite 100 #6009

San Francisco, CA 94133

PROXY STATEMENT

FOR THE 2025 ANNUAL MEETING OF STOCKHOLDERS

June 4, 2025