---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-295562"
form_type: "8-K/A"
ticker: "PFE"
cik: "0000078003"
company_name: "PFIZER INC"
filed_at: "2023-12-14T23:59:59+00:00"
generated_at: "2026-06-07T13:13:40.984404+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Pfizer completes $43B acquisition of Seagen; Seagen becomes wholly owned subsidiary

## Summary
- Acquisition closed Dec 14, 2023; $229 per share in cash for total enterprise value approx. $43 billion.
- Adds Seagen's four approved medicines (ADCETRIS, PADCEV, TIVDAK, TUKYSA) and ADC technology.
- Pfizer's oncology pipeline doubled to 60 programs across multiple modalities.
- To address FTC concerns, Pfizer irrevocably donated U.S. royalty rights from Bavencio (avelumab) to AACR.
- Pfizer's oncology portfolio now includes over 25 approved medicines and biosimilars across >40 indications.

## SEC filing metadata
- accession: 0001193125-23-295562
- form_type: 8-K/A
- ticker: PFE
- cik: 0000078003
- company_name: PFIZER INC
- filed_at: 2023-12-14T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 2.02, 2.01, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/78003/000119312523295562/0001193125-23-295562-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/78003/000119312523295562/d612444d8ka.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-295562
- JSON: https://secwatch.observer/filing/0001193125-23-295562.json
- Plain text: https://secwatch.observer/filing/0001193125-23-295562.txt

## Key facts
- M&A Transactions
  PFIZER INC completed an acquisition involving Seagen Inc. for $229 in cash per share, for a total enterprise value of approximately $43 billion (closed 2023-12-14).
  - Action: acquisition
  - Counterparty: Seagen Inc.
  - Consideration: $229 in cash per share, for a total enterprise value of approximately $43 billion
  - Closing: 2023-12-14
  source text: Pfizer completed its acquisition of all outstanding common stock of Seagen for $229 in cash per share, for a total enterprise value of approximately $43 billion.
  evidence_url: https://www.sec.gov/Archives/edgar/data/78003/000119312523295562/0001193125-23-295562-index.htm

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