Sangamo Therapeutics has announced that the U.S. Food and Drug Administration (FDA) has cleared the investigational new drug (IND) application for its ST-503 program. ST-503 is an epigenetic therapy designed to treat idiopathic small fiber neuropathy (iSFN), a type of chronic neuropathic pain that severely affects patients’ quality of life. The clearance marks a major milestone as Sangamo prepares to launch a Phase I/II clinical trial in mid-2025 to evaluate the safety and efficacy of this novel treatment.
Neuropathic pain is a debilitating condition affecting millions of people worldwide. Unlike acute or sporadic pain, chronic neuropathic pain, such as that caused by iSFN, persists over years and can be resistant to existing therapies like antidepressants, anticonvulsants, and opioids. Sangamo’s ST-503 program addresses this unmet medical need by targeting the SCN9A gene, which encodes the Nav1.7 sodium channel, a key player in pain signaling pathways.
“FDA clearance of the IND application to evaluate ST-503 in idiopathic small fiber neuropathy represents an important milestone for Sangamo on our journey to becoming a neurology genomic medicine company,” said Nathalie Dubois-Stringfellow, PhD, chief development officer at Sangamo. “We strongly believe in the power of our zinc finger technology to address neurological conditions and are excited about our plans to advance this program into the clinic next year.”
ST-503 uses an adeno-associated virus (AAV) vector to deliver a zinc finger repressor (ZFR) that selectively silences the SCN9A gene. Preclinical studies in animal models have shown that this targeted approach reduces the expression of Nav1.7 sodium channels in sensory neurons, significantly alleviating pain hypersensitivity. A single intrathecal administration of ST-503 was both effective and well tolerated, with no off-target effects observed in nonhuman primates.
The upcoming Phase I/II clinical trial will involve patients with intractable pain caused by iSFN. This study aims to assess the safety, tolerability, and initial efficacy of a one-time intrathecal dose of ST-503. If successful, Sangamo plans to explore the potential of this therapy for other forms of chronic neuropathic pain.
With approximately 43,000 people in the U.S. affected by iSFN and nearly 40 million Americans living with peripheral neuropathies, the need for effective treatments is urgent. Sangamo’s ST-503 offers hope for patients whose lives are dominated by chronic, untreatable pain.
This development underscores Sangamo Therapeutics’ commitment to advancing genomic medicine and exploring innovative solutions for neurological diseases. By leveraging its zinc finger technology, Sangamo aims to transform the treatment landscape for chronic pain and other neurological disorders.
