Freeline Therapeutics : Corporate Presentation – July

Corporate Presentation

August 2023

Legal disclaimer

This presentation contains statements that constitute "forward looking statements" as that term is defined in the United States Private Securities Litigation Reform Act of 1995, including statements that express the opinions, expectations, beliefs, plans, objectives, assumptions or projections of Freeline Therapeutics Holdings plc (the "Company") regarding future events or future results, in contrast with statements that reflect historical facts. Examples include statements regarding upcoming milestones in its Phase 1/2 GALILEO-1dose-finding clinical trial of FLT201, including trial design, dosing of patients and data readouts; that its product candidate FLT201 has the potential to be best-in-class and/or first-in-class, stop disease progression, improve outcomes for people with Gaucher disease type 1 with a one-time therapy, deliver a continuous level of enzyme and penetrate deeper tissues that current therapies do not reach sufficiently; that its longer-acting GCase variant may provide an opportunity for a best-in-class gene therapy for GBA1-linked Parkinson's disease; regarding the Company's expectations regarding its use of cash and cash runway; as well as any other discussion of the Company's strategies, financing plans, business plans and prospects, capital allocation objectives and manufacturing, research, pipeline and clinical trial plans. In some cases, you can identify such forward-looking statements by terminology such as "anticipate," "intend," "believe," "estimate," "plan," "seek," "potential," "project" or "expect," "may," "will," "would," "could" or "should," the negative of these terms or similar expressions. Forward-looking statements are based on management's current beliefs and assumptions and on information currently available to the Company, and you should not place undue reliance on such statements. Forward-looking statements are subject to many risks and uncertainties, including the Company's recurring losses from operations; the uncertainties inherent in research and development of the Company's product candidates, including statements regarding the timing of initiation, completion and the outcome of clinical studies or trials and related preparatory work and regulatory review, regulatory submission dates, regulatory approval dates and/or launch dates, as well as risks associated with preclinical and clinical data, including the possibility of unfavorable new preclinical, clinical or safety data and further analyses of existing preclinical, clinical or safety data; the Company's ability to design and implement successful clinical trials for its product candidates; whether the Company's cash resources will be sufficient to fund the Company's foreseeable and unforeseeable operating expenses and capital expenditure requirements for the Company's expected timeline in light of management's substantial doubt regarding the Company's ability to continue as a going concern for at least 12 months from the issuance date of its most recent quarterly financial statements; the Company's failure to demonstrate the safety and efficacy of its product candidates; the fact that results obtained in earlier stage clinical testing may not be indicative of results in future clinical trials; the Company's ability to enroll patients in clinical trials for its product candidates; the possibility that one or more of the Company's product candidates may cause serious adverse, undesirable or unacceptable side effects or have other properties that could delay or prevent their regulatory approval or limit their commercial potential; the Company's ability to obtain and maintain regulatory approval of its product candidates; the Company's limited manufacturing experience which could result in delays in the development, regulatory approval or commercialization of its product candidates; the Company's ability to identify or discover additional product candidates, or failure to capitalize on programs or product candidates. Such risks and uncertainties may cause the statements to be inaccurate and readers are cautioned not to place undue reliance on such statements. Many of these risks are outside of the Company's control and could cause its actual results to differ materially from those it thought would occur. The forward-looking statements included in this presentation are made only as of the date hereof. The Company does not undertake, and specifically declines, any obligation to update any such statements or to publicly announce the results of any revisions to any such statements to reflect future events or developments, except as required by law.

For further information, please refer to the Company's reports and documents filed with the U.S. Securities and Exchange Commission. You may obtain these documents by visiting EDGAR on the SEC website at www.sec.gov.

Certain information contained in this presentation relates to, or is based on, studies, publications, surveys and other data obtained from third party sources and the Company's internal estimates and research. While the Company believes these third-party sources to be reliable as of the date of this presentation, they have not been independently verified, and makes no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third party sources. In addition, all of the market data included in this presentation involve a number of assumptions and limitations, and there can be no guarantee as to the accuracy or reliability of such assumptions. Finally, although the Company believes its own internal research is reliable, such research has not been verified by any independent source.

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Creating better gene therapies for chronic debilitating diseases

Potential first- and best-in-class lead program

Highly differentiated gene therapy candidate FLT201 for Gaucher disease type 1 in first-in-human clinical trial

Near-term data readout in Gaucher disease

Initial safety and enzyme activity data for FLT201 expected in Q3 2023

Innovative research

Lead research program leverages same novel GCase variant as FLT201

for GBA1-linked Parkinson's disease

Experienced management team

Seasoned leaders with the experience and expertise to drive progress and execution

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Lead clinical program with first- and best-in-class potential with research extending innovation into larger disease area

Indication	Approximate	Research	Preclinical	Phase 1/2	Phase 3
patient #

Gaucher

Disease Type 1

FLT201

GBA1-linked

Parkinson's

Disease

~18K

~190K

Estimated patient numbers for Gaucher disease Type 1 are for US, UK, EU4 and Israel (Hematology. 2017 Mar;22(2):65-73. doi: 10.1080/10245332.2016.1240391; this figure represents the total theoretical genetic prevalence of the indication. The seroprevalence of antibodies against the AAVS3 capsid renders some patients ineligible for AAV gene therapy. We estimate approximately 60% would be eligible for AAVS3 gene therapy. Company estimate of patient numbers for GBA1-linked PD are for US, UK and EU4 .

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FLT201

in Gaucher

Disease