4D Molecular Therapeutics : 310 INGLAXA Phase 1/2 Interim Clinical Data Presentation – February 2023

Update from INGLAXA Phase 1/2 Clinical Trials

• Development Plans for 4D-310 Genetic Medicine for Fabry Disease Cardiomyopathy

February 22, 2023

Legal Disclaimer

This Presentation contains forward looking statements that involve substantial risks and uncertainties.All statements, other than statements of historical facts, contained in this Presentation, including statements regarding our clinical development plans, strategy, future operations, future financial position, prospects, plans, and objectives of management, are forward looking statements.The words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "target," "should," "would," and similar expressions are intended to identify forward looking statements, although not all forward looking statements contain these identifying words.We may not actually achieve the plans, intentions, or expectations disclosed in these forward looking statements, and you should not place undue reliance on these forward looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward looking statements. In addition, the forward looking statements included in this Presentation represent our views as of the date of this Presentation.We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward looking statements in the future, we specifically disclaim any obligation to do so.These forward looking statements should not be relied upon as representing our views as of any date subsequent to the date of this Presentation.

This Presentation discusses our product candidates that are under preclinical study and in clinical trials, and which have not yet been approved for marketing by the U.S. Food and Drug Administration. No representation is made as to the safety or effectiveness of our product candidates for the therapeutic use for which they are being studied.

This Presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such data and estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

This Presentation shall not constitute an offer to sell or the solicitation of an offer to buy securities.

© 2022 4D Molecular Therapeutics. All Rights Reserved.

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We are Boldly Innovating to Unlock the Full Potential of Genetic Medicines for Millions of Patients

COMPANY		Emeryville,	~140 Employees
FDMT	GMP Facilities
CA
	R&D Headquarters
PLATFORM	Directed Evolution	~1 BILLION	Targeted & Evolved Vectors
Payload Design
capsid sequences
		GMP Manufacturing
PRODUCT	Vector Modularity	Clinical-Stage Vectors in 3 Therapeutic Areas

ENGINE

CLINICAL DEVELOPMENT

5 Clinical Candidates for 7 Patient Populations

STRATEGY	Fully Integrated Large Market Genetic Medicines Company

© 2022 4D Molecular Therapeutics. All Rights Reserved. | CONFIDENTIAL

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Pipeline: 5 Clinical-Stage Product Candidates incl. Large Markets

THREE THERAPEUTIC AREAS, RARE & LARGE SUSTAINABLE PATIENT POPULATIONS

VECTOR	PRODUCT	INDICATION	RESEARCH	IND-ENABLING	PHASE 1 / 2	PHASE 3	PRODUCT
Delivery	CANDIDATE	CANDIDATE	RIGHTS
R100	OPHTHALMOLOGY
Intravitreal
	4D-150	Wet AMD
	Diabetic Macular Edema
	4D-125	XLRP
	4D-110	CHM
	4D-175	Geographic Atrophy
A101	PULMONOLOGY
Aerosol
	4D-710	CF modulator-ineligible
	CF eligible for modulators
	4D-725	A1AT Deficiency
C102	CARDIOLOGY	Today's Focus
IV		Fabry Disease
	4D-310
	Cardiomyopathy
© 2022 4D Molecular Therapeutics. All Rights Reserved. | CONFIDENTIAL					4

Key Takeaways for Today: 4D-310

1. Heart: Clinical POC for single low dose IV delivery, transgene expression & efficacy o 3rd 4DMT Vector with Clinical POC
2. Safety: Generally well-tolerated with no liver, heart or DRG toxicity observed
3. Transient acute atypical hemolytic uremic syndrome ("aHUS"): o Understood & manageable
4. Approval pathway clear

© 2022 4D Molecular Therapeutics. All Rights Reserved. | CONFIDENTIAL

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