Sanofi’s Intravitreal Gene Therapy Receives FDA Fast Track Designation for Geographic Atrophy

The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to SAR446597, a one-time intravitreal gene therapy developed by Sanofi for the treatment of geographic atrophy (GA) due to age-related macular degeneration (AMD). This designation is intended to accelerate the development and review of drugs that address serious medical conditions and meet unmet clinical needs.

Addressing an Unmet Need in GA

Geographic atrophy represents an advanced stage of AMD, for which current treatment options remain limited. The FDA’s Fast Track designation for SAR446597 highlights the potential of this novel therapy to significantly impact the clinical management of GA and improve patient outcomes. This status provides Sanofi with opportunities for more frequent engagement with the FDA, the possibility of priority review, and a faster pathway to regulatory approval.

Dual-Targeting Approach: A Novel Mechanism of Action

SAR446597 works by delivering genetic material that encodes two therapeutic antibody fragments. These fragments are designed to inhibit two key components of the complement pathway: C1s, which plays a role in the classical pathway, and factor Bb, which is part of the alternative pathway.

By targeting both pathways simultaneously, SAR446597 aims to provide more comprehensive and sustained complement suppression within the retinal microenvironment. This dual-targeting mechanism is expected to address the underlying pathophysiology of complement-mediated retinal diseases more effectively than current treatment modalities.

Potential Clinical Benefits

Sanofi's gene therapy approach offers several potential advantages:

       • Sustained therapeutic effect through long-term expression of the encoded proteins after a single administration

       • Reduced treatment burden by eliminating the need for frequent intravitreal injections

       • Comprehensive complement pathway inhibition, which could result in better disease control and slower progression of GA

Clinical Development Pipeline

Sanofi plans to initiate a phase 1/2 clinical study to evaluate the safety, tolerability, and efficacy of SAR446597 in patients with geographic atrophy. In addition, the company is actively studying another gene therapy, SAR402663, in a phase 1/2 trial for the treatment of wet AMD (ClinicalTrials.gov Identifier: NCT06660667).