FOGHO CORPORATE OVERVIEW Leveraging unique insights into the chromatin regulatory system to pioneer a new class of precision therapies in oncology and beyond September 2022 Forward-Looking Statements FORWARD LOOKING STATEMENTS This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as "could," "may," "might," "will," " ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ______________________ FORM 10-Q _____________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ¨TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________________ to __________________ Commission File Number: 001-39634 ______________________ F ...

FOGHO CORPORATE OVERVIEW Leveraging unique insights into the chromatin regulatory system to pioneer a new class of precision therapies in oncology and beyond June 2022 Forward-Looking Statements FORWARD LOOKING STATEMENTS This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as "could," "may," "might," "will," "likel ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ______________________ FORM 10-Q _____________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ¨TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________________ to __________________ Commission File Number: 001-39634 ______________________ ...

Overview - The dysregulation of the Chromatin Regulatory System is implicated in approximately 50% of all cancers, representing a significant market opportunity[3] - Foghorn Therapeutics is well-positioned to discover and develop first-in-class precision medicines targeting cancer and other diseases[4] - Foghorn Therapeutics had $479.5 million in pro forma cash and equivalents as of September 30, 2021[5] Pipeline and Programs - FHD-286 (BRG1/BRM) is an enzyme inhibitor targeting AML and Uveal melanoma, with initial clinical data expected in H1 2022[8, 23] - FHD-609 (BRD9) is a protein degrader targeting Synovial Sarcoma, with initial clinical data expected as early as H1 2022[8, 23] - Selective BRM modulators, including enzyme inhibitors and protein degraders, are being developed for BRG1 mutated cancers, impacting over 100,000 patients per year[52] - Selective ARID1B protein degrader is in pre-clinical development for ARID1A mutated cancers, potentially impacting over 175,000 patients per year[60] Strategic Collaborations - Strategic collaboration with Loxo Oncology at Lilly includes $380 million upfront ($300 million cash and $80 million in Foghorn common stock at $20 per share), 50/50 U S economics on two programs, tiered ex-U S royalties, and $1.3 billion in potential milestones[10] - Merck collaboration to drug single specified transcription factor target includes $425 million in up-front, research, development and sales-based milestones and up to low double-digit royalties on product sales[68]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _________________________ FORM 10-K _________________________ (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-39634 _________________________ Foghorn Therapeutics Inc. (Exa ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ______________________ FORM 10-Q _____________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR ¨TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________________ to __________________ Commission File Number: 001-39634 ___________________ ...

Targeting the Chromatin Regulatory System Broadening the Impact of Precision Medicines for Oncology and Other Diseases September 2021 Forward-Looking Statements This presentation contains forward-looking statements. All statements other than statements of historical facts contained in Disclaimer, Confidentiality, and Forward-Looking Statements this presentation are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as "may," "will," "should," "expect," "plan ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ______________________ FORM 10-Q _____________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 OR ¨TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________________ to __________________ Commission File Number: 001-39634 ______________________ F ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ______________________ FORM 10-Q _____________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ¨TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________________ to __________________ Commission File Number: 001-39634 ______________________ ...