Sangamo Therapeutics Receives FDA Fast Track Designation For ST-503, An Epigenetic Regulator For Intractable Small Fiber Neuropathy Pain

Sangamo Therapeutics, Inc., a genomic medicine company, announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to ST-503, an investigational epigenetic regulator being developed for the treatment of intractable pain caused by small fiber neuropathy (SFN), a chronic and often debilitating form of neuropathic pain.

Fast Track Designation is intended to support the development of treatments for serious conditions that lack effective therapies. The designation allows companies to have more frequent communication with the FDA throughout the development process and may also make a program eligible for Accelerated Approval and Priority Review if certain requirements are met. This pathway is designed to help speed up the availability of promising therapies for patients who need them most.

Nathalie Dubois-Stringfellow, Ph.D., Chief Development Officer at Sangamo, expressed the company’s appreciation for the FDA’s decision, noting that SFN severely affects patients’ quality of life and that current treatment options are limited. She emphasized that the designation highlights the significant unmet medical need in SFN and supports the development of non-opioid alternatives for pain management. Sangamo is preparing to dose the first participant in the Phase 1/2 clinical trial and plans to share updates once data become available.

ST-503 is being studied in the ongoing Phase 1/2 STAND trial, which is currently in the patient recruitment and enrollment phase. In September 2025, Sangamo presented new nonclinical data at the 9th International Congress on Neuropathic Pain. The findings showed that ST-503 demonstrated strong durability, potency, and selectivity in nonhuman primate models, along with a favorable safety profile. These results further support its potential as a treatment for chronic neuropathic pain. Additional information from the scientific presentation is available on Sangamo’s website. The company expects to administer the first dose in the Phase 1/2 STAND study in the coming months.