---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-045585"
form_type: "8-K"
ticker: "RGNX"
cik: "0001590877"
company_name: "REGENXBIO Inc."
filed_at: "2025-03-04T23:59:59+00:00"
generated_at: "2026-05-25T14:01:26.232833+00:00"
event_type: "other"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# REGENXBIO closes strategic partnership with Nippon Shinyaku for MPS gene therapies

## Summary
- Partnership closed for development/commercialization of RGX-121 (MPS II) and RGX-111 (MPS I) in US and Asia.
- RGX-121 on track as first gene therapy for MPS II; potential FDA approval as early as late 2025.
- CEO Curran Simpson highlights transformative potential for MPS patient populations.
- No financial terms disclosed in this filing; partnership was previously announced.

## SEC filing metadata
- accession: 0001193125-25-045585
- form_type: 8-K
- ticker: RGNX
- cik: 0001590877
- company_name: REGENXBIO Inc.
- filed_at: 2025-03-04T23:59:59+00:00
- event_type: other
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1590877/000119312525045585/0001193125-25-045585-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1590877/000119312525045585/d909911d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-045585
- JSON: https://secwatch.observer/filing/0001193125-25-045585.json
- Plain text: https://secwatch.observer/filing/0001193125-25-045585.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.