---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-028449"
form_type: "8-K"
ticker: "ENZN"
cik: "0000727510"
company_name: "Viskase Holdings, Inc."
filed_at: "2026-03-16T23:59:59+00:00"
generated_at: "2026-05-15T12:12:58.078753+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Enzon extends exchange offer for Series C Preferred to March 19, 2026

## Summary
- Exchange offer for Series C Non-Convertible Redeemable Preferred now expires 5:00 p.m. ET on March 19, 2026.
- Holders may exchange Series C Preferred shares for Enzon common stock at the stated ratio.
- Extension announced via press release on March 16, 2026; prior expiration date is not disclosed.
- Merger with Viskase Companies, Inc. remains pending; S-4 registration statement filed with SEC.

## SEC filing metadata
- accession: 0001104659-26-028449
- form_type: 8-K
- ticker: ENZN
- cik: 0000727510
- company_name: Viskase Holdings, Inc.
- filed_at: 2026-03-16T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/727510/000110465926028449/0001104659-26-028449-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/727510/000110465926028449/tm268789d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-028449
- JSON: https://secwatch.observer/filing/0001104659-26-028449.json
- Plain text: https://secwatch.observer/filing/0001104659-26-028449.txt

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