Spruce Biosciences announced Monday that the U.S. Food and Drug Administration has granted Breakthrough Therapy Designation to the company's tralesinidase alfa enzyme replacement therapy (TA-ERT) for the treatment of Sanfilippo Syndrome Type B, an ultra-rare, serious, and fatal genetic disease. The designation represents a significant regulatory milestone for addressing this devastating pediatric condition.
Clinical Evidence Supporting FDA Decision
The FDA's designation is backed by integrated group-level clinical data demonstrating TA-ERT's therapeutic impact across multiple biomarkers and clinical measures. The clinical evidence shows that TA-ERT produces a rapid, profound, and durable effect in normalizing Cerebral Spinal Fluid Heparan Sulfate Non-Reducing End, a key biomarker associated with the disease progression.
Beyond biomarker normalization, the therapy demonstrated the ability to stabilize cortical grey matter volume and cognitive function in children with Sanfilippo Syndrome Type B. This preservation of brain structure and function represents a critical therapeutic outcome for a disease characterized by progressive neurodegeneration.
Regulatory Timeline and Market Response
Spruce Biosciences plans to submit the Biologics License Application for TA-ERT in the first quarter of 2026, setting the stage for potential regulatory approval of this enzyme replacement therapy. The Breakthrough Therapy Designation is expected to facilitate expedited review and development processes with the FDA.
The market responded enthusiastically to the announcement, with Spruce Biosciences' stock (SPRB) soaring 135.4 percent to $20.83 in pre-market trading on the Nasdaq. This dramatic increase reflects investor confidence in the therapy's commercial potential and the significant unmet medical need in treating Sanfilippo Syndrome Type B.
Addressing Ultra-Rare Disease Burden
Sanfilippo Syndrome Type B represents an ultra-rare genetic disorder with limited treatment options. The FDA's Breakthrough Therapy Designation for TA-ERT acknowledges the therapy's potential to address a serious condition where no adequate treatment currently exists, highlighting the critical importance of developing targeted therapies for rare pediatric diseases.
