---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-003121"
form_type: "8-K"
ticker: "FBIO"
cik: "0001429260"
company_name: "Fortress Biotech, Inc."
filed_at: "2026-01-13T23:59:59+00:00"
generated_at: "2026-05-16T10:38:40.085101+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# FDA approves ZYCUBO for Menkes disease; Cyprium gets PRV, up to $129M milestones

## Summary
- FDA approved ZYCUBO (copper histidinate) as first and only U.S. treatment for Menkes disease in pediatric patients.
- Rare Pediatric Disease PRV issued at approval and will be transferred to Cyprium, a majority-owned Fortress subsidiary.
- Cyprium eligible for tiered royalties on net sales and up to $129M in aggregate development and sales milestones from Sentynl.
- Early ZYCUBO treatment showed median overall survival of 177.1 months vs 17.6 months in external control (≈80% risk reduction).
- Fortress notes three FDA approvals in 15 months (Emrosi, UNLOXCYT, ZYCUBO) and recent $28M upfront from Checkpoint sale to Sun Pharma.

## SEC filing metadata
- accession: 0001104659-26-003121
- form_type: 8-K
- ticker: FBIO
- cik: 0001429260
- company_name: Fortress Biotech, Inc.
- filed_at: 2026-01-13T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1429260/000110465926003121/0001104659-26-003121-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1429260/000110465926003121/fbio-20260113x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-003121
- JSON: https://secwatch.observer/filing/0001104659-26-003121.json
- Plain text: https://secwatch.observer/filing/0001104659-26-003121.txt

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