Clinical Report: FDA approves gene therapy for MPS IIIA

Overview

The FDA has approved rebisufligene etisparvovec-hopf (Fayuvi) as the first treatment for pediatric patients with mucopolysaccharidosis type IIIA. This gene therapy introduces a functional SGSH gene.

Background

Mucopolysaccharidosis type IIIA, also known as Sanfilippo syndrome type A, is a rare inherited disorder that leads to progressive neurological decline in children. Prior to this approval, treatment options were limited to symptom management.

Data Highlights

The FDA evaluated the safety and effectiveness of rebisufligene etisparvovec in an open-label, single-arm, multicenter study. Cognitive outcomes were assessed using mean score changes in patients aged 2 to 5 years, showing stability or improvement compared to an untreated historical control cohort.

Key Findings

• Rebisufligene etisparvovec is administered as a single intravenous infusion.
• The therapy introduces a functional copy of the SGSH gene, enabling the production of sulfamidase.
• Common adverse reactions (≥5%) include increased liver enzymes, nausea, vomiting, fever, decreased appetite, and reductions in white blood cell and platelet counts.
• Thrombotic microangiopathy is among the treatment's safety warnings.
• Genomic integration of the introduced genetic material may pose a long-term risk of tumor development.

Clinical Implications

Administration of rebisufligene etisparvovec requires careful monitoring of liver enzymes and blood counts, with corticosteroids given to manage potential infusion reactions.

Conclusion

The approval of rebisufligene etisparvovec provides a new treatment option for pediatric patients with mucopolysaccharidosis type IIIA.

Related Resources & Content

1. FDA, FDA, 2026 -- FDA Approves First Gene Therapy for Pediatric Patients with Sanfilippo Syndrome Type A
2. MDSpire News — FDA Approves Gene Therapy for Severe Pediatric LAD-I
3. Frontiers in Medicine — RNA activation as a precision dosing modality: MTL-CEBPA for controlled enzyme elevation in MPS I-H
4. the medicine maker — Hunting for a Cure
5. MDSpire News — FDA OKs First SMA Gene Replacement Therapy
6. FDA Approves First Gene Therapy for Pediatric Patients with Sanfilippo Syndrome Type A | FDA
7. Package Insert - FAYUVI
8. Sanfilippo syndrome: consensus guidelines for clinical care - PMC