MPS IIIA is mucopolysaccharidosis type IIIA (Sanfilippo syndrome type A), a progressive lysosomal storage disease caused by SGSH deficiency with predominant neurodegeneration. It is one subtype within MPS III and typically shows earlier and more severe progression than some other subtypes.
Ultragenyx Pharmaceutical announced positive long-term clinical data for UX111 gene therapy for Sanfilippo syndrome Type A, with up to 8.5 years of follow-up showing sustained biomarker reductions and functional improvements. The company resubmitted its BLA to the FDA in January 2026.
Ultragenyx Pharmaceutical received an Incomplete Response Letter from the FDA for its UX111 gene therapy resubmission for Sanfilippo syndrome type A, requesting additional documentation. The company announced a 10% workforce reduction and expects profitability by 2027.
Ultragenyx reported Q4 2025 revenues of $207 million, up 25% year-over-year, while announcing a 10% workforce reduction and resubmission of its UX111 gene therapy application following positive long-term clinical data.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT04360265 |
Follow-up Study of AAV-Mediated Gene Transfer (UX111; Previously Known as ABO-102) for MPS Type IIIA |
ENROLLING_BY_INVITATION | PHASE3 |
| NCT04088734 |
Gene Transfer Study of ABO-102 in Patients With Middle and Advanced Phases of MPS IIIA Disease |
TERMINATED | PHASE1/PHASE2 |
| NCT02716246 |
Phase I/II/III Gene Transfer Clinical Trial of scAAV9.U1a.hSGSH |
RECRUITING | PHASE2/PHASE3 |
