---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-222923"
form_type: "8-K"
ticker: "APLS"
cik: "0001492422"
company_name: "Apellis Pharmaceuticals, Inc."
filed_at: "2026-05-14T12:45:19+00:00"
generated_at: "2026-05-14T12:52:46.267286+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 1.0
calibrated_materiality_score: 1.0
confidence: "high"
source: SEC EDGAR
---

# Biogen completes $5.3B acquisition of Apellis; stockholders get $41 cash + CVR up to $4

## Summary
- Tender offer accepted 105.7M shares (~82.4%); merger effective May 14, 2026.
- Consideration per share: $41 cash plus CVR worth up to $4 based on SYFOVRE sales milestones.
- CVR milestones: $2 if SYFOVRE net sales ≥$1.5B by 2030; $2 if ≥$2B by 2031 (or $4 if second met first).
- Apellis common stock delisted from Nasdaq; intends to terminate SEC reporting obligations.
- Board resigned; Michael Dambach (Biogen designee) becomes sole director.

## SEC filing metadata
- accession: 0001193125-26-222923
- form_type: 8-K
- ticker: APLS
- cik: 0001492422
- company_name: Apellis Pharmaceuticals, Inc.
- filed_at: 2026-05-14T12:45:19+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 1.0
- calibrated_materiality_score: 1.0
- confidence: high
- sec_items: 1.01, 1.02, 2.01, 5.01, 3.01, 3.03, 5.03, 5.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/d23709d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-222923
- JSON: https://secwatch.observer/filing/0001193125-26-222923.json
- Plain text: https://secwatch.observer/filing/0001193125-26-222923.txt

## Key facts
- Executive change
  Mikael Dolsten resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Gerald Chan resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Cedric Francois resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  A. Sinclair Dunlop resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Michael Dambach was appointed as Director at Apellis Pharmaceuticals, Inc..
  - Action: appointed
  - Role: Director
  source text: the director of Purchaser as of immediately prior to the Effective Time, Michael Dambach, became the director of the Company.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Stephanie Monaghan O’Brien resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Craig Wheeler resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Paul Fonteyne resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Keli Walbert resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Executive change
  Alec Machiels resigned as Member of the Board of Directors at Apellis Pharmaceuticals, Inc..
  - Action: resigned
  - Role: Member of the Board of Directors
  source text: Mikael Dolsten, Paul Fonteyne, Stephanie Monaghan O’Brien, A. Sinclair Dunlop, Alec Machiels, Keli Walbert, Gerald Chan, Cedric Francois and Craig Wheeler each resigned from his or her respective position as a member of the Board of Directors of the Company and any committee thereof.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Governance Changes
  Apellis Pharmaceuticals, Inc.: Certificate of incorporation amended and restated in its entirety effective at the Effective Time pursuant to the Merger Agreement.
  - Change: charter amendment
  source text: Pursuant to the terms of the Merger Agreement, effective as of the Effective Time, the Company’s certificate of incorporation was amended and restated in its entirety.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- Governance Changes
  Apellis Pharmaceuticals, Inc.: Bylaws amended and restated in their entirety effective at the Effective Time pursuant to the Merger Agreement.
  - Change: bylaw amendment
  source text: Pursuant to the terms of the Merger Agreement, effective as of the Effective Time, the Company’s bylaws were amended and restated in their entirety.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm
- M&A Transactions
  Apellis Pharmaceuticals, Inc. underwent a change of control involving Biogen Inc. for approximately $5.3 billion (closed 2026-05-14).
  - Action: change of control
  - Counterparty: Biogen Inc.
  - Consideration: approximately $5.3 billion
  - Closing: 2026-05-14
  source text: in January 2026 and (B) the target performance levels for all other Company PSUs. The aggregate amount to be paid by Purchaser in the Offer and the Merger is approximately $5.3 billion, excluding related fees and expenses and, for the avoidance of doubt, any amounts that may become payable pursuant to the CVRs. Biogen and Purchaser will fund the acquisition of
  evidence_url: https://www.sec.gov/Archives/edgar/data/1492422/000119312526222923/0001193125-26-222923-index.htm

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