Sangamo Therapeutics Receives U.S. FDA Fast Track Designation for ST-503 for the Treatment of Small Fiber Neuropathy

Rhea-AI Summary

Sangamo Therapeutics (NASDAQ: SGMO) announced that the U.S. FDA granted Fast Track Designation to ST-503 for the treatment of intractable pain from small fiber neuropathy (SFN).

The designation may enable more frequent FDA interactions and could make ST-503 eligible for Accelerated Approval or Priority Review if criteria are met. ST-503 is an investigational epigenetic regulator currently in the Phase 1/2 STAND study, with patient recruitment underway and first dosing expected in the coming months. Sangamo previously presented nonclinical data showing durability, potency, selectivity and a favorable safety profile in nonhuman primates.

Positive

• FDA Fast Track granted to ST-503
• Phase 1/2 STAND study active with recruitment underway
• Nonclinical data showed durability, potency, selectivity in nonhuman primates
• Company expects to dose first Phase 1/2 patient in coming months

Negative

• No human efficacy data available yet; first-in-human dosing pending
• Fast Track only expedites development pathway; approval is not assured

News Market Reaction – SGMO

+3.48%

18 alerts

+3.48% News Effect

+23.8% Peak in 1 hr 4 min

+$6M Valuation Impact

$168M Market Cap

0.8x Rel. Volume

On the day this news was published, SGMO gained 3.48%, reflecting a moderate positive market reaction. Argus tracked a peak move of +23.8% during that session. Our momentum scanner triggered 18 alerts that day, indicating notable trading interest and price volatility. This price movement added approximately $6M to the company's valuation, bringing the market cap to $168M at that time.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Trial phase: Phase 1/2 Congress edition: 9th International Congress

2 metrics

Trial phase Phase 1/2 ST-503 STAND study development stage

Congress edition 9th International Congress Neuropathic Pain meeting where ST-503 data were presented

Market Reality Check

Price: $0.4400 Vol: Today’s volume 4,137,605 ...

low vol

$0.4400 Last Close

Volume Today’s volume 4,137,605 shares is below the 20-day average of 9,297,829, with relative volume at 0.45x. low

Technical Shares at $0.4591 are trading below the $0.60 200-day moving average, reflecting a longer-term downtrend.

Peers on Argus

SGMO is down 4.11% while peers show mixed moves: ACOG (-2.83%), VTYX (-1.16%), C...

SGMO is down 4.11% while peers show mixed moves: ACOG (-2.83%), VTYX (-1.16%), CRBU (-1.06%), NVCT (+2.57%), NTHI (+6.00%), suggesting stock-specific factors.

Historical Context

5 past events · Latest: Dec 02 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 02	Fast Track news	Positive	+3.5%	FDA granted Fast Track to ST-503 for small fiber neuropathy pain.
Nov 21	Regulatory update	Positive	+10.0%	FDA accepted rolling BLA submission request for ST-920 in Fabry.
Nov 06	Earnings and update	Negative	-16.3%	Q3 2025 showed sharp revenue drop, wider loss and tight liquidity.
Oct 30	Earnings call notice	Neutral	-1.4%	Scheduled Q3 2025 results release and conference call details.
Sep 04	Clinical data update	Positive	-0.7%	Registrational STAAR study data showed renal benefit and safety in Fabry.

Pattern Detected

Recent news shows mostly positive catalysts with generally aligned price reactions, though there was at least one instance where strong clinical data coincided with a slight negative move.

Recent Company History

Over the last six months, Sangamo has reported multiple important milestones, including Fabry disease STAAR study data, rolling BLA plans for ST-920, and detailed Q3 2025 financials showing tighter liquidity. Clinical and regulatory updates often produced positive moves, while the Q3 results with a wider loss and going-concern warning saw a sharper decline. Today’s Fast Track designation for ST-503 extends the pipeline beyond Fabry disease, complementing prior Fabry-focused clinical progress.

Market Pulse Summary

This announcement highlights FDA Fast Track Designation for ST-503, an epigenetic regulator for smal...

Analysis

This announcement highlights FDA Fast Track Designation for ST-503, an epigenetic regulator for small fiber neuropathy, and ongoing enrollment in the Phase 1/2 STAND study. In context, Sangamo has also advanced its Fabry program toward a planned BLA while its latest quarterly report disclosed tight liquidity and a going-concern warning. Key factors to watch include clinical readouts for ST-503, regulatory progress for ST-920, and any financing or partnership developments.

Key Terms

fast track designation, epigenetic regulator, small fiber neuropathy, accelerated approval, +4 more

8 terms

fast track designation regulatory

"the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to ST-503"

A "fast track designation" is a process that speeds up the review and approval of a product or project, allowing it to reach the market or be completed more quickly than usual. For investors, it can signal that a product may become available sooner, potentially leading to earlier revenue or benefits, and indicating a priority status that might influence company performance and market opportunities.

epigenetic regulator medical

"ST-503, an investigational epigenetic regulator for the treatment of intractable pain"

An epigenetic regulator is a molecule—often a protein or a drug—that changes how genes are turned on or off without altering the underlying DNA sequence. Think of genes as lights in a building and epigenetic regulators as the switches or dimmers that control which rooms are lit; by altering those switches they can change cell behavior, disease processes, and treatment responses. Investors watch them because targeting or measuring these regulators can create new therapies, indicate drug effectiveness, or introduce safety and development risks.

small fiber neuropathy medical

"for the treatment of intractable pain due to small fiber neuropathy (SFN)"

Small fiber neuropathy is a medical condition where the tiny nerve fibers that sense pain, temperature and control some automatic body functions become damaged, causing pain, numbness or burning sensations often in hands and feet. It matters to investors because its diagnosis and treatment drive clinical trials, regulatory reviews, reimbursement decisions and potential market demand for therapies or diagnostics—similar to how a fault in a building’s wiring can prompt costly repairs and upgrades.

accelerated approval regulatory

"may also be eligible to apply for Accelerated Approval and Priority Review"

Accelerated approval is a process that allows new medical treatments to be approved more quickly than usual if they address serious or life-threatening conditions and show promising early results. For investors, it signals that a treatment may reach the market sooner, potentially boosting a company's prospects, but it also involves some uncertainty since full evidence of effectiveness is still being gathered.

priority review regulatory

"eligible to apply for Accelerated Approval and Priority Review if relevant criteria are met"

Priority review is a regulatory fast-track that shortens the time an agency spends evaluating a drug, vaccine or medical device application so a decision comes sooner than normal. For investors, it matters because a faster review is like an express lane to market: it can speed revenue potential and reduce regulatory uncertainty, but it does not guarantee approval and still requires the product to meet safety and effectiveness standards.

phase 1/2 study medical

"We are preparing to dose the first patient in our Phase 1/2 study"

A phase 1/2 study is an early-stage clinical trial that first tests a new drug or treatment for how safe it is and what dose people can tolerate (phase 1), then expands to see whether it shows initial signs of working in patients (phase 2). Think of it as a combined test-drive and small pilot launch: it helps companies gather crucial safety and early effectiveness data faster than separate trials, so investors use the results to gauge whether a treatment is worth further development or funding, while remembering that outcomes at this stage are still preliminary and risky.

chronic neuropathic pain medical

"small fiber neuropathy (SFN), a type of chronic neuropathic pain"

Long-lasting pain caused by damaged or malfunctioning nerves that keeps sending false pain signals to the brain, often felt as burning, stabbing, tingling or numbness — like a shorted wiring system that won’t stop shocking. It matters to investors because it represents a large, persistent medical need with potential for recurring treatment revenue, clear clinical trial opportunities, regulatory attention, and significant commercial upside if a safe, effective therapy is approved.

nonhuman primates medical

"durability, potency and selectivity of ST-503 in nonhuman primates, alongside a favorable safety profile"

Nonhuman primates are members of the primate family—such as monkeys and apes—used in biomedical research because their biology and immune systems are closer to humans than other animals. For investors, they matter because studies in these animals often shape safety and effectiveness data required by regulators, affecting drug development timelines, costs, supply constraints, and public or regulatory scrutiny much like a crucial early road test that can determine whether a medicine moves forward to human trials.

AI-generated analysis. Not financial advice.

RICHMOND, Calif., Dec. 02, 2025 (GLOBE NEWSWIRE) -- Sangamo Therapeutics, Inc. (Nasdaq: SGMO), a genomic medicine company, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to ST-503, an investigational epigenetic regulator for the treatment of intractable pain due to small fiber neuropathy (SFN), a type of chronic neuropathic pain.

Fast Track Designation aims to facilitate the development and expedite the review of new therapeutics that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs. Companies granted this designation are given the opportunity for more frequent interactions with the FDA. These clinical programs may also be eligible to apply for Accelerated Approval and Priority Review if relevant criteria are met.

“We are very pleased to receive FDA Fast Track Designation for ST-503. SFN is a debilitating chronic pain disorder, with limited effective treatment options currently available,” said Nathalie Dubois-Stringfellow, Ph.D., Sangamo’s Chief Development Officer. “This designation underscores the high unmet patient need in SFN and the urgency to develop safe and effective nonopioid treatment alternatives. We are preparing to dose the first patient in our Phase 1/2 study and look forward to sharing data once available.”

ST-503 is currently being evaluated in the Phase 1/2 STAND study, where patient recruitment and enrollment are in progress. In September 2025, Sangamo presented updated nonclinical data highlighting the pharmacology and safety of ST-503 in chronic neuropathic pain at the 9th International Congress on Neuropathic Pain. The data demonstrated the durability, potency and selectivity of ST-503 in nonhuman primates, alongside a favorable safety profile, supporting its development for the treatment of chronic neuropathic pain. A copy of the presentation is available in the Presentations section of the Sangamo website. Sangamo expects to dose the first Phase 1/2 STAND study patient in the coming months.

About the STAND Study
Sangamo is preparing for the Phase 1/2 STAND study, a multicenter, double-blind, randomized, sham-controlled dose escalation study to assess the safety, tolerability and preliminary efficacy of a one-time dose of ST-503, administered intrathecally to patients with SFN. The STAND study is enrolling adult patients with a confirmed diagnosis of SFN who have pain that has been refractory to first line medical therapies for at least 6 months.

About Small Fiber Neuropathy
Small Fiber Neuropathy (SFN) is a condition that damages small nerve fibers, leading to burning, prickling, stabbing or “lightning-like” intractable pain, numbness, as well as autonomic issues like heart rate changes, digestion problems and orthostatic intolerance. SFN can be caused by a broad array of pathologies impacting the central or peripheral nervous systems, such as surgical trauma, spinal cord injury, nerve compression, neurological and infectious diseases, or metabolic and hereditary syndromes. SFN has an estimated prevalence of 53 people out of every 100,000 in the U.S., and more broadly, peripheral neuropathies are estimated to affect nearly 40 million Americans. Antidepressants, anticonvulsants, opioids and topical therapies are potential treatment options, although no long-lasting or curative therapies are currently available for SFN patients, leading to a high unmet medical need for this patient population.

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 ability of the Fast Track designation to facilitate the development and expedite the review of ST-503, the ability of ST-503 to meet relevant criteria in order to be eligible to apply for Accelerated Approval and Priority Review, the therapeutic potential of ST-503, including its potential to improve the lives of patients and to have a favorable effect on small fiber neuropathy, Sangamo’s expectation for, and timelines related to, dosing patients in the Phase 1/2 STAND study and other statements that are not historical fact. These statements are not guarantees of future performance and are subject to risks and uncertainties that are difficult to predict. Sangamo’s actual results may differ materially and adversely from those expressed. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties related to: reliance on results of early clinical trials, such as the Phase 1/2 STAND study, which results are not necessarily predictive of future clinical trial results; the research and development process, including the enrollment, operation and results of clinical trials and the presentation of clinical data; the unpredictable regulatory approval process for product candidates across multiple regulatory authorities; the manufacturing of products and product candidates; the commercialization of approved products; the potential for technological developments that obviate technologies used by Sangamo; 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; 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-503 and FDA Fast Track on December 2, 2025?

Sangamo announced that the FDA granted Fast Track Designation to ST-503 for small fiber neuropathy on Dec 2, 2025.

How does FDA Fast Track affect SGMO's ST-503 development timeline?

Fast Track enables more frequent FDA interactions and could allow Accelerated Approval or Priority Review if ST-503 meets relevant criteria.

When will Sangamo dose the first patient in the Phase 1/2 STAND study for ST-503 (SGMO)?

Sangamo stated it expects to dose the first Phase 1/2 STAND patient in the coming months after recruitment and enrollment progressed.

What preclinical evidence supports ST-503 for chronic neuropathic pain (SGMO)?

Presented nonclinical data demonstrated durability, potency, selectivity and a favorable safety profile in nonhuman primates.

Does FDA Fast Track mean ST-503 is approved for small fiber neuropathy?

No. Fast Track is a development and review designation; it does not mean ST-503 is approved.

Where can investors find Sangamo’s ST-503 presentation and updates (SGMO)?

Sangamo said a copy of the presentation is available in the Presentations section of its website and updates will be provided as data become available.