SEC Form DEFA14A filed by Foghorn Therapeutics Inc.

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

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.

Foghorn Therapeutics Inc.

Annual Meeting of Stockholders

Tuesday, June 17, 2025 9:00 AM, Eastern Time

Annual Meeting to be held live via the internet - please visit www.proxydocs.com/FHTX for more details.

To attend the meeting online and/or participate, you must register at www.proxydocs.com/FHTX

For a convenient way to view proxy materials, VOTE, and obtain directions to attend the meeting go to www.proxydocs.com/FHTX

To vote your proxy while visiting this site, you will need the 12 digit control number in the box below.

This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. This is not a ballot. You cannot use this notice to vote your shares. We encourage you to access and review all of the important information contained in the proxy materials before voting.

Under United States Securities and Exchange Commission rules, proxy materials do not have to be delivered in paper. Proxy materials can be distributed by making them available on the internet.

If you want to receive a paper or e-mail copy of the proxy material, you must request one. There is no charge to you for requesting a copy. In order to receive a paper package in time for this year’s meeting, you must make this request on or before June 6, 2025.

SEE REVERSE FOR FULL AGENDA

PROPOSAL