Sangamo's Gene Therapy for Fabry Disease Clears Major FDA Milestone With Rolling BLA Submission Path

Sangamo Therapeutics Inc. (SGMO) has secured a significant regulatory green light from the U.S. Food and Drug Administration, which has agreed to a rolling submission process for its Biologics License Application (BLA) evaluating isaralgagene civaparvovec—an investigational gene therapy targeting Fabry disease in adult patients.

Understanding the Disease and Treatment Approach

Fabry disease represents a rare lysosomal storage disorder triggered by genetic mutations affecting the galactosidase alpha (GLA) enzyme. This deficiency cascades into progressive damage across multiple organ systems—kidneys, heart, nervous system, eyes, skin, and gastrointestinal tract. Current therapeutic options focus on symptom management rather than addressing the underlying genetic root cause.

Sangamo’s isaralgagene civaparvovec takes a fundamentally different approach. The gene therapy candidate is engineered to provide a one-time treatment intervention that addresses the disease’s pathophysiology directly. Rather than ongoing symptomatic management, the therapy aims to deliver durable benefits across affected organ systems simultaneously—a significant advantage over existing standards of care.

Clinical Evidence Supporting Approval Path

The company’s Phase 1/2 STAAR study has produced compelling data justifying FDA’s accelerated review pathway. Most notably, the study demonstrated a positive mean annualized estimated glomerular filtration rate (eGFR) slope at the 52-week assessment point across the entire treated patient cohort. The FDA has determined this endpoint will serve as the primary efficacy measure for approval evaluation.

The multi-organ clinical benefits observed in trial data underscore the potential of this single-administration approach to fundamentally shift treatment paradigms for Fabry disease patients.

Regulatory Designations and Timeline

The therapeutic candidate has accumulated substantial regulatory momentum. Isaralgagene civaparvovec holds Orphan Drug, Fast Track, and RMAT (Regenerative Medicine Advanced Therapy) designations from the FDA. Internationally, it has earned Orphan Medicinal Product status and PRIME eligibility from the European Medicines Agency, plus Innovative Licensing and Access Pathway recognition from the U.K. regulatory authority.

Sangamo intends to initiate rolling BLA submissions beginning in the fourth quarter of 2025, utilizing the FDA’s accelerated approval pathway to expedite market access for this potentially transformative therapy.