Foghorn Therapeutics Inc.

Index

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements that are based on management’s beliefs and assumptions and on information currently available to management. All statements other than statements of historical facts contained in this Annual Report on Form 10-K are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements include, but are not limited to, statements concerning:

•the initiation, timing, progress, enrollment, results, and timing of results and regulatory filings of our research and development programs and our preclinical and clinical studies, including those included in our collaboration with Eli Lilly and Company (“Lilly”);

•our ability to advance any product candidates that we may develop and to successfully complete preclinical and clinical studies;

•our ability to leverage our initial programs to develop additional product candidates using our Gene Traffic Control® platform;

•developments related to our competitors and our industry;

•our ability to expand the target populations of our programs and the availability of patients for clinical testing;

•our ability to obtain regulatory approval for FHD-909 and any future product candidates from the U.S. Food and Drug Administration (the “FDA”) and other regulatory authorities;

•our ability to identify and enter into future license agreements and collaborations;

•our ability to continue to rely on our contract development and manufacturing organizations (“CDMOs”) or contract research organizations (“CROs”), including those located outside the United States, such as those located in China, for our manufacturing and research needs;

•regulatory developments in the United States and foreign countries;

•general economic conditions, including recessionary conditions, interest rates, monetary fluctuations and supply chain constraints;

•ongoing and potential geopolitical instability and armed conflicts;

•our ability to attract and retain key scientific and management personnel; and

•the scope of protection we are able to establish, maintain and enforce for intellectual property rights covering our current and future product candidates, and our Gene Traffic Control platform.

The forward-looking statements in this Annual Report on Form 10-K are only predictions and are based largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this Annual Report on Form 10-K and are subject to a number of known and unknown risks, uncertainties and assumptions, including those described under the section entitled “Item 1A. Risk Factors” in this Annual Report on Form 10-K. Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. Moreover, we operate in an evolving environment. New risks and uncertainties may emerge from time to time, and it is not possible for management to predict all risks and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.

SUMMARY OF RISK FACTORS

Below is a summary of the principal factors that make an investment in our common stock speculative or risky. This summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary and other risks that we face can be found below under the heading “Item 1A. Risk Factors” and should be carefully considered, together with other information in this Annual Report on Form 10-K and our other filings with the SEC, before making an investment decision regarding our common stock.

•We have a limited operating history and have no products approved for commercial sale, which may make it difficult for you to evaluate our current business and predict our future success and viability.

•We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.

•We will need substantial additional funding. If we are unable to raise capital when needed or under acceptable terms, we could be forced to delay, reduce or eliminate our research and product development programs or future commercialization efforts.

•We are heavily dependent on the success of our product candidates, which are in preclinical and Phase 1 clinical development. We may not be successful in our efforts to identify and develop potential product candidates. If these efforts are unsuccessful, or if we experience significant delays, we may never become a commercial stage company or generate any revenues, and our business could be materially harmed.

•Our clinical trials may fail to demonstrate substantial evidence of the safety and efficacy of our product candidates, which would delay or prevent regulatory approval of the product candidates, limit their commercial potential or result in significant negative consequences following any potential marketing approval.

•We or our collaboration partner may not be able to file Investigational New Drug Applications (“INDs”) or IND amendments to commence clinical trials of our product candidates on the timelines we expect, and even if we or they are able to, the FDA may not permit us to proceed. For our partnered programs, we may not be able to exert unilateral control over the development of such product candidates.

•We are not able to exert unilateral control over the development of FHD-909 through our collaboration with Lilly and may not be able to exert unilateral control over future product candidates as part of that collaboration or other future collaborations.

•There is substantial competition in our field, which may result in others developing or commercializing products that may be competitors of ours before we do.

•We are highly dependent on our key personnel. If we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement our business strategy.

•If we are unable to adequately protect our proprietary technology and platform or obtain and maintain patent protection for our technology and products or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize technology and products similar or identical to ours, and our ability to successfully develop and commercialize our technology and products may be impaired.

•Unfavorable global macroeconomic conditions, geopolitical trends, and armed conflict, together with legislative, executive, and administrative actions meant to address these and other conditions, could adversely affect our business, financial condition or results of operations.