Exhibit 99.1

SANGAMO THERAPEUTICS ANNOUNCES STRATEGIC UPDATE AND REPORTS

THIRD QUARTER 2023 FINANCIAL RESULTS

Recent Business Highlights

Program Highlights

Neurology Epigenetic Regulation Programs – Progressed IND-enabling activities for Nav1.7; presented updated preclinical data at Prion 2023; presented preclinical data on zinc finger activators at the European Society of Gene and Cell Therapy (ESGCT); made significant progress in identifying new, potentially transformative AAV delivery capsids.

Fabry Disease – Dosed total of 25 patients in Phase 1/2 STAAR study; all patients dosed to date continue to demonstrate sustained, elevated α-Gal A levels for up to three years for the longest treated patient; received Regenerative Medicine Advanced Therapy (RMAT) Designation from U.S. FDA; enrolled sufficient patients in the Phase 1/2 study believed to provide a preliminary assessment of safety and efficacy; deferring Phase 3 planning investments and actively seeking partners and investment.

CAR-Tregs – Received approval for accelerated dosing protocol for Phase 1/2 STEADFAST study from European regulatory authorities; dosed the first patient in the second dose cohort; successfully manufactured product candidate for third and new fourth dose levels; presented updated preclinical data at ESGCT; seeking a collaboration partner or direct investment in CAR-Tregs.

Hemophilia A (Pfizer) – dosing complete in Phase 3 AFFINE trial; pivotal data read-out expected in mid-2024; BLA and MAA submissions anticipated in second half of 2024.

Third Quarter 2023 Financial Results

Revenues

GAAP and Non-GAAP Operating Expenses

Cash, Cash Equivalents and Marketable Securities

Updated Financial Guidance for 2023

Upcoming Events

Investor Conferences

Conference Call to Discuss Third Quarter 2023 Results

About Sangamo Therapeutics

Forward-Looking Statements

This press release contains forward-looking statements regarding our current expectations. These forward-looking statements include, without limitation, statements relating to: the therapeutic and commercial potential of our product candidates, the anticipated plans and timelines of Sangamo and our collaborators for screening, enrolling and dosing patients in and conducting our ongoing and potential future clinical trials and presenting clinical data from our clinical trials, including expectations regarding the conclusion of dosing in our Phase 1/2 STAAR study, preparations and plans for patient dosing in the STEADFAST study, the potential for acceleration of the study timeline and the availability of data therefrom, the anticipated advancement of our product candidates to late-stage development, including Sangamo’s plans to seek a potential partner or additional financing to proceed with potential future Phase 3 trials of isaralgagene civaparvovec and the timing thereof, the timeline to present data from the Phase 3 AFFINE trial and to make BLA and MAA submissions for giroctocogene fitelparvovec, expectations regarding advancement of our preclinical neurology programs, including announcement of data from, and anticipated IND submissions related to, such programs, plans to seek a partner for or investor in our CAR-Treg program, expectations concerning our strategic prioritization and restructuring, including plans to close our Brisbane facility and the expected charges and cost savings associated with such restructuring, future potential cost reductions, our expected cash runway, our 2023 financial guidance related to GAAP and non-GAAP total operating expenses, impairments and stock-based compensation, our plans to participate in industry and investor conferences, and other statements that are not historical fact. These statements are not guarantees of future performance and are subject to certain risks and uncertainties that are difficult to predict. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties related to Sangamo’s ability to execute its strategic prioritization and restructuring as currently contemplated; the actual charges associated with the restructuring being higher than anticipated or changes to the assumptions on which the estimated charges associated with the restructuring are based; Sangamo’s ability to achieve projected cost savings in connection with the restructuring and to further reduce operating expenses; unintended consequences from the restructuring that impact Sangamo’s business; our lack of capital resources to fully develop, obtain regulatory approval for and commercialize our product candidates, including our ability to secure the funding required to initiate a potential Phase 3 trial of isaralgagene civaparvovec in a timely manner or at all; our need for substantial additional funding to execute our operating plan and to continue to operate as a going concern; the potential of our preclinical programs utilizing zinc finger technology to address neurological health disorders; the effects of macroeconomic factors or financial challenges, including as a result of the ongoing overseas conflict, current or potential future bank failures, inflation and rising interest rates, on the global business environment, healthcare systems and business and operations of Sangamo and our collaborators, including the initiation and operation of clinical trials; the research and development process, including the enrollment, operation and results of clinical trials and the presentation of clinical data; the impacts of clinical trial delays, pauses and holds on clinical trial timelines and commercialization of product candidates; the uncertain timing and unpredictable nature of clinical trial results, including the risk that therapeutic effects in the Phase 3 AFFINE trial will not be durable in patients as well as the risk that the therapeutic effects observed in the latest preliminary clinical data from the Phase 1/2 STAAR study will not be durable in patients and that final clinical trial data from the study will not validate the safety and efficacy of isaralgagene civaparvovec, and that the

patients withdrawn from ERT will remain off ERT; the unpredictable regulatory approval process for product candidates across multiple regulatory authorities; reliance on results of early clinical trials, which results are not necessarily predictive of future clinical trial results, including the results of any Phase 3 trial of our product candidates; the potential for technological developments that obviate technologies used by Sangamo; our reliance on collaborators and our potential inability to secure additional collaborations, and our ability to achieve expected future financial performance.

There can be no assurance that we and our collaborators will be able to develop commercially viable products. Actual results may differ materially from those projected in these forward-looking statements due to the risks and uncertainties described above and other risks and uncertainties that exist in the operations and business environments of Sangamo and our collaborators. These risks and uncertainties are described more fully in our Securities and Exchange Commission, or SEC, filings and reports, including in our Annual Report on Form 10-K for the year ended December 31, 2022, as supplemented by our Quarterly Report on Form 10-Q for the quarter ended September 30, 2023 to be filed with the SEC, and future filings and reports that Sangamo makes from time to time with the SEC. Forward-looking statements contained in this announcement are made as of this date, and we undertake no duty to update such information except as required under applicable law.

Non-GAAP Financial Measures

To supplement our financial results and guidance presented in accordance with GAAP, we present non-GAAP operating expenses, which excludes stock-based compensation expense and impairment of goodwill, indefinite-lived intangible assets and long-lived assets from GAAP operating expenses. We believe that this non-GAAP financial measure, when considered together with our financial information prepared in accordance with GAAP, can enhance investors’ and analysts’ ability to meaningfully compare our results from period to period and to our forward-looking guidance, and to identify operating trends in our business. We have excluded stock-based compensation expense because it is a non-cash expense that may vary significantly from period to period as a result of changes not directly or immediately related to the operational performance for the periods presented, and we have excluded impairment of goodwill, indefinite-lived intangible assets and long-lived assets to facilitate a more meaningful evaluation of our current operating performance and comparisons to our operating performance in other periods. This non-GAAP financial measure is in addition to, not a substitute for, or superior to, measures of financial performance prepared in accordance with GAAP. We encourage investors to carefully consider our results under GAAP, as well as our supplemental non-GAAP financial information, to more fully understand our business.

SELECTED CONSOLIDATED FINANCIAL DATA