Sangamo Therapeutics Initiates Rolling Submission of BLA to U.S. FDA for ST-920 in Fabry Disease

Rhea-AI Summary

Sangamo Therapeutics (Nasdaq: SGMO) has initiated a rolling submission of a Biological License Application (BLA) to the U.S. FDA seeking accelerated approval for isaralgagene civaparvovec (ST-920) to treat adults with Fabry disease.

The registrational STAAR study showed a positive mean annualized eGFR slope at 52 weeks across dosed patients, and the FDA agreed that eGFR slope will serve as an endpoint to support accelerated approval. Sangamo expects to complete the BLA submission under the accelerated pathway in Q2 2026. ST-920 has received Orphan Drug, Fast Track, and RMAT designations from the FDA and regulatory recognitions from EMA and UK regulators.

Positive

• STAAR study: positive mean annualized eGFR slope at 52 weeks
• FDA agreed eGFR slope will serve as an endpoint to support accelerated approval
• Initiated rolling BLA submission to FDA (allows ongoing review)
• Multiple regulatory designations: Orphan, Fast Track, RMAT, EMA PRIME eligibility

Negative

• BLA submission not yet complete; expected finish in Q2 2026

Key Figures

eGFR follow-up duration 52 weeks STAAR study mean annualized eGFR slope assessment timeframe

BLA completion target Q2 2026 Expected completion of rolling BLA submission under accelerated approval

Market Reality Check

$0.4464 Last Close

Volume Pre-news volume 3,011,530 vs 20-day average 9,088,041 (relative volume 0.33x). low

Technical Price $0.4382 is trading below the $0.59 200-day moving average, near the $0.3846 52-week low and well under the $2.84 52-week high.

Peers on Argus

Key biotech peers like ACOG (-2.19%), NVCT (-1.17%), VTYX (-5.88%), CRBU (-4.14%) and NTHI (-18.01%) were down, indicating broader sector softness, while this positive BLA update is company-specific.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 02	Fast Track designation	Positive	+3.5%	FDA Fast Track designation for ST-503 in small fiber neuropathy.
Nov 21	BLA rolling approval	Positive	+10.0%	FDA acceptance of rolling BLA submission request for ST-920 in Fabry.
Nov 06	Q3 2025 earnings	Negative	-16.3%	Weak revenues, larger loss, tight cash and going concern warning.
Oct 30	Earnings call notice	Neutral	-1.4%	Announcement and logistics for upcoming Q3 2025 earnings call.
Sep 04	Fabry trial data	Positive	-0.7%	Positive STAAR Fabry data with durable response and favorable safety.

Pattern Detected

Recent clinically positive Fabry and neurology updates (ST‑920, ST‑503) generally saw aligned or modestly positive reactions, while weak Q3 financials with going concern language led to a sharp selloff.

Recent Company History

This announcement extends Sangamo’s Fabry strategy, following detailed STAAR data and repeated FDA confirmation that eGFR slope at 52 weeks can support accelerated approval. In September 2025 and November 2025, ST‑920 data and rolling BLA acceptance produced mixed but mostly aligned price responses. Parallel neurology progress included Fast Track status for ST‑503. However, the Q3 2025 10‑Q highlighted a sharp revenue drop, larger losses, tight liquidity and a going concern warning, underscoring financing and listing risks alongside today’s regulatory momentum.

Market Pulse Summary

This announcement advances ST-920 by initiating a rolling BLA under the accelerated approval pathway, with the FDA agreeing that 52-week eGFR slope can support review. It builds on prior STAAR data and earlier confirmation of this endpoint. Against a backdrop of tight liquidity and a going concern warning in Q3 2025, investors may focus on regulatory progress, future submission timing in Q2 2026, and any updates on funding plans.

Key Terms

estimated glomerular filtration rate (eGFR) medical

"positive mean annualized estimated glomerular filtration rate (eGFR) slope at 52-weeks"

Estimated glomerular filtration rate (eGFR) is a test that measures how well your kidneys are filtering waste from your blood. It helps doctors check kidney health and detect problems early, much like how a water filter's effectiveness can be tested by how clean the water becomes.

rolling submission regulatory

"has initiated a rolling submission of a BLA to the FDA"

A rolling submission is a regulatory filing process where a company sends portions of its application to health authorities as each section is completed, rather than waiting to submit the entire package at once. For investors, this can shorten the time to review and potential approval and reduces the risk of a single big setback—think of it like mailing chapters of a manuscript to an editor as they’re finished so feedback and progress happen sooner.

biological license application (BLA) regulatory

"rolling submission of a BLA to the FDA seeking accelerated approval"

A biological license application (BLA) is a formal regulatory filing seeking permission to market a biologic medicine — a treatment made from living cells or organisms, such as vaccines, antibodies, or gene therapies. For investors, a BLA is like an application for a product’s “license to sell”: approval clears the path to commercial revenue while rejection or delay signals regulatory risk that can significantly affect a company’s valuation and future cash flow.

accelerated approval pathway regulatory

"serve as an endpoint to support accelerated approval pathway"

The accelerated approval pathway is a process that allows new medicines to be approved more quickly based on early evidence that they may be effective, rather than waiting for full proof. This can help patients access promising treatments faster, but it also means ongoing studies are needed to confirm the benefits. For investors, it highlights potential faster market entry and earlier revenue opportunities, along with some uncertainty about long-term outcomes.

orphan drug regulatory

"has been granted Orphan Drug, Fast Track and RMAT designations"

A drug designated for an orphan disease is a medicine developed to treat a rare condition that affects only a small number of people. Regulators often give these drugs special incentives—such as reduced costs, faster review, and temporary exclusive selling rights—to encourage development, which matters to investors because those incentives can make a small market financially viable and reduce competition, much like a temporary patent on a niche product.

fast track regulatory

"has been granted Orphan Drug, Fast Track and RMAT designations"

A fast track designation is a regulatory label that speeds up the review and communication between a drug developer and regulators for treatments addressing serious illnesses or unmet medical needs. For investors, it matters because it can shorten development time and reduce regulatory delays—like getting a VIP lane at the airport—raising the chance of earlier market access and potential revenue, though it does not guarantee approval.

rmat regulatory

"has been granted Orphan Drug, Fast Track and RMAT designations"

A Regenerative Medicine Advanced Therapy (RMAT) designation is a regulatory fast-track status for cell, gene or tissue-based therapies that show promise for treating serious conditions. It acts like an express lane with extra support from regulators—potentially shortening review time and enabling earlier approval paths—which can reduce development risk and speed a therapy toward the market, making it a material value signal for investors in biotech stocks.

gene therapy medical

"investigational gene therapy for the treatment of adults with Fabry disease"

Gene therapy is a medical technique that involves altering or replacing faulty genes in a person's cells to treat or prevent disease. It is considered a promising area of innovation because it has the potential to provide long-term or even permanent solutions to genetic conditions. For investors, advancements in gene therapy can signal opportunities in biotech companies and emerging treatments with significant growth potential.

AI-generated analysis. Not financial advice.

STAAR study demonstrated positive mean annualized estimated glomerular filtration rate (eGFR) slope at 52-weeks across all dosed patients in the study, which U.S. Food and Drug Administration (FDA) has agreed will serve as an endpoint to support accelerated approval pathway 

Isaralgagene civaparvovec continues to show favorable safety and tolerability profile

Sangamo expects to complete Biological License Application (BLA) submission under accelerated approval pathway in second quarter of 2026

RICHMOND, Calif., Dec. 18, 2025 (GLOBE NEWSWIRE) -- Sangamo Therapeutics, Inc. (Nasdaq: SGMO), a genomic medicine company, has initiated a rolling submission of a BLA to the FDA seeking accelerated approval of isaralgagene civaparvovec, or ST-920, a wholly owned investigational gene therapy for the treatment of adults with Fabry disease.

Rolling submission allows for completed modules of the BLA to be submitted and reviewed by the FDA on an ongoing basis rather than waiting for the entire BLA to be submitted at once. 

“The initiation of our BLA submission marks an important milestone for Sangamo and for Fabry patients in need,” said Nathalie Dubois-Stringfellow, Ph.D., Sangamo’s Chief Development Officer. “The compelling data from our STAAR study shows the potential of ST-920 to provide safe and long-lasting clinical benefits to a wide range of Fabry disease patients. We look forward to working with the FDA as we continue to advance the regulatory process.”

The totality of data from the registrational STAAR study demonstrated the potential for isaralgagene civaparvovec as a one-time, durable treatment of the underlying pathology of Fabry disease to provide meaningful, multi-organ, clinical benefits above current standards of care. Furthermore, the STAAR study demonstrated a positive mean annualized eGFR slope at 52-weeks across all dosed patients in the study, which the FDA has agreed will serve as endpoint to support accelerated approval.

Isaralgagene civaparvovec has been granted Orphan Drug, Fast Track and RMAT designations from the FDA, Orphan Medicinal Product designation and PRIME eligibility from the European Medicines Agency and Innovative Licensing and Access Pathway from U.K. Medicines and Healthcare products Regulatory Agency.

Sangamo expects to complete submission of the BLA to the FDA under the accelerated approval pathway in the second quarter of 2026.

About the STAAR Study
The Phase 1/2 STAAR study is a global open-label, single-dose, dose-ranging, multicenter clinical study designed to evaluate isaralgagene civaparvovec, or ST-920, a gene therapy product candidate in patients with Fabry disease. Isaralgagene civaparvovec requires a one-time infusion without preconditioning.

About Fabry Disease
Fabry disease is a lysosomal storage disorder caused by mutations in the galactosidase alpha gene (GLA), which leads to deficient alpha-galactosidase A (α-Gal A) enzyme activity, which is necessary for metabolizing globotriaosylceramide (Gb3). The buildup of Gb3 in the cells can cause serious damage to vital organs, including the kidney, heart, nerves, eyes, gut and skin. Symptoms of Fabry disease can include decreased or absent sweat production, heat intolerance, angiokeratoma (skin blemishes), vision problems, kidney disease, heart failure, gastrointestinal disturbance, mood disorders, neuropathic pain and tingling in the extremities.

About Sangamo Therapeutics

Sangamo Therapeutics is a genomic medicine company dedicated to translating ground-breaking science into medicines that transform the lives of patients and families afflicted with serious neurological diseases who do not have adequate or any treatment options. Sangamo believes that its zinc finger epigenetic regulators are ideally suited to potentially address devastating neurological disorders and that its capsid discovery platform can expand delivery beyond currently available intrathecal delivery capsids, including in the central nervous system. Sangamo’s pipeline also includes multiple partnered programs and programs with opportunities for partnership and investment. To learn more, visit www.sangamo.com and connect with us on LinkedIn and X.

Forward-Looking Statements

This press release contains forward-looking statements regarding Sangamo’s current expectations. These forward-looking statements include, without limitation, statements relating to: the safety and efficacy and therapeutic potential of isaralgagene civaparvovec, including the potential for it to be a one-time, durable treatment option for Fabry disease to provide meaningful, multi-organ clinical benefits above current standards of care; the potential for isaralgagene civaparvovec to qualify for the FDA’s accelerated approval program, including the adequacy of data generated in the Phase 1/2 STAAR study to support any such approval; expectations concerning the availability of additional data to support a potential BLA submission for isaralgagene civaparvovec, and the timing of such submission; 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 lack of capital resources to obtain regulatory approval for and commercialize its product candidates in a timely manner or at all, including the ability to secure a commercialization partner for ST-920; the uncertain timing and unpredictable nature of clinical trial results, including the risk that preliminary or topline data is not indicative of final results, that the therapeutic effects observed in the latest 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, including that the 52-week data from the Phase 1/2 STAAR study will not support a BLA submission and/or that the 104-week data from such study will not verify the clinical benefit of isaralgagene civaparvovec or support FDA approval, and that the patients withdrawn from ERT will remain off ERT; Sangamo’s need for substantial additional funding to execute its operating plan and to continue to operate as a going concern; the effects of macroeconomic factors or financial challenges on the global business environment, healthcare systems and Sangamo’s business and operations; the research and development process; the unpredictable regulatory approval process for product candidates across multiple regulatory authorities; the potential for technological developments that obviate technologies used by Sangamo; Sangamo’s reliance on collaborators and the potential inability to secure additional collaborations; and Sangamo’s ability to achieve expected future financial performance.

All forward-looking statements about Sangamo’s future plans and expectations, including Sangamo’s development plans for its product candidates, are subject to Sangamo’s ability to secure adequate additional funding. There can be no assurance that Sangamo and its current or potential future partners 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 its collaborators. These risks and uncertainties are described more fully in Sangamo’s Securities and Exchange Commission, or SEC, filings and reports, including in Sangamo’s Annual Report on Form 10-K for the year ended December 31, 2024, as supplemented by its Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, each 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 Sangamo undertakes no duty to update such information except as required under applicable law.

Contacts

Investor Relations
Louise Wilkie
ir@sangamo.com

Media Inquiries
Melinda Hutcheon
media@sangamo.com

FAQ

What did Sangamo announce about ST-920 (SGMO) on December 18, 2025?

Sangamo initiated a rolling BLA submission to the FDA seeking accelerated approval of ST-920 for adults with Fabry disease.

What clinical endpoint did the FDA agree will support accelerated approval for ST-920 (SGMO)?

The FDA agreed that the mean annualized eGFR slope at 52 weeks from the STAAR study will serve as an endpoint to support accelerated approval.

When does Sangamo expect to complete the BLA submission for ST-920 (SGMO)?

Sangamo expects to complete the BLA submission under the accelerated pathway in Q2 2026.

What regulatory designations has ST-920 (SGMO) received from regulators?

ST-920 has received Orphan Drug, Fast Track and RMAT designations from the FDA and EMA PRIME eligibility plus other EU/UK recognitions.

How does a rolling BLA submission affect FDA review timing for SGMO?

A rolling submission lets Sangamo submit completed BLA modules for ongoing FDA review rather than waiting to file the full application at once.