---
schema_version: "secwatch.filing_event.v1"
accession: "0000950157-26-000699"
form_type: "8-K/A"
ticker: "BIIB"
cik: "0000875045"
company_name: "BIOGEN INC."
filed_at: "2026-06-10T20:49:37+00:00"
generated_at: "2026-06-10T20:51:58.881849+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.1
calibrated_materiality_score: 0.1
confidence: "high"
source: SEC EDGAR
---

# Biogen amends 8-K to note Apellis acquisition not significant, no financial statements required

## Summary
- Acquisition of Apellis closed May 14, 2026; deemed not significant under Regulation S-X after further analysis.
- Items 9.01(a) and (b) financial statements and pro forma information not required; prior obligation withdrawn.
- All other disclosures from the Original Report regarding the merger remain unchanged.

## SEC filing metadata
- accession: 0000950157-26-000699
- form_type: 8-K/A
- ticker: BIIB
- cik: 0000875045
- company_name: BIOGEN INC.
- filed_at: 2026-06-10T20:49:37+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.1
- calibrated_materiality_score: 0.1
- confidence: high
- sec_items: 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/875045/000095015726000699/0000950157-26-000699-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/875045/000095015726000699/form8-ka.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950157-26-000699
- JSON: https://secwatch.observer/filing/0000950157-26-000699.json
- Plain text: https://secwatch.observer/filing/0000950157-26-000699.txt

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