Hunter syndrome, or mucopolysaccharidosis type II, is a rare X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase leading to glycosaminoglycan accumulation. It causes progressive multisystem disease affecting skeletal, respiratory, cardiovascular, and neurologic function with variable severity. The condition primarily affects males.
A class action lawsuit was filed against REGENXBIO covering the period from February 9, 2022 to January 27, 2026, following FDA clinical holds on gene therapies RGX-111 and RGX-121 after a CNS tumor was discovered in a trial participant.
Global orphan drug sales are forecast to reach $409 billion by 2032, representing one-fifth of prescription drug sales, with Johnson & Johnson and Argenx leading the market amid regulatory uncertainty.
The FDA has denied or discouraged at least eight drug applications in the past year, including treatments for rare diseases, raising concerns about regulatory consistency and the future of experimental therapies.
The FDA placed clinical holds on Regenxbio's RGX-111 and RGX-121 gene therapies following a tumor case in an MPS I patient. The company's stock fell nearly 18% on the news.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT07344376 |
An Extension Study to Assess the Long-term Safety and Efficacy of Hunterase (Idursulfase Beta) |
COMPLETED | PHASE3 |
| NCT06031259 |
Extension Study of Idursulfase-IT Along With Elaprase in Children and Adults With Hunter Syndrome and Cognitive Impairment |
ACTIVE_NOT_RECRUITING | PHASE2/PHASE3 |
| NCT05795361 |
Post-trial Access Program of Idursulfase-IT Along With Elaprase in Children With Hunter Syndrome |
AVAILABLE | |
| NCT05494593 |
A Study of ELAPRASE in Treatment-naïve Participants With Hunter Syndrome (Mucopolysaccharidosis [MPS] II) |
WITHDRAWN | PHASE4 |
| NCT05422482 |
A Study to Evaluate the Safety, Tolerability, PK and PD of Intracerebroventricular GC1123 in Patients with MPS Ⅱ |
ACTIVE_NOT_RECRUITING | PHASE1 |
| NCT05058391 |
A Study of Elaprase in Children and Adults With Hunter Syndrome (Mucopolysaccharidosis II) in India |
COMPLETED | PHASE4 |
| NCT04976231 |
MPS II Immunophenotyping |
TERMINATED | |
| NCT03920540 |
A Study of GC1111 in Hunter Syndrom Patients |
COMPLETED | PHASE3 |
| NCT03582449 |
Intensive Pharmacovigilance Program for Elaprase (SHP ELA-701) |
COMPLETED | |
| NCT03292887 |
Hunter Outcome Survey (HOS) |
COMPLETED |
