---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-22-067375"
form_type: "8-K"
ticker: "REGN"
cik: "0000872589"
company_name: "REGENERON PHARMACEUTICALS, INC."
filed_at: "2022-06-02T23:59:59+00:00"
generated_at: "2026-06-25T05:17:26.638311+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Regeneron enters amended deal with Sanofi for full rights to Libtayo; pays $900M upfront

## Summary
- Regeneron gains sole worldwide rights to develop and commercialize Libtayo, effective upon regulatory approvals.
- Regeneron will pay Sanofi $900M upfront within 10 business days of effective date.
- Regeneron will pay an 11% royalty on Libtayo net sales through March 2034, plus up to $200M in milestone payments.
- Development cost reimbursement rate under Antibody LCA increased from 10% to 20% effective April 1, 2022.
- Transition services, distribution, and manufacturing agreements support the handover from Sanofi.

## SEC filing metadata
- accession: 0001104659-22-067375
- form_type: 8-K
- ticker: REGN
- cik: 0000872589
- company_name: REGENERON PHARMACEUTICALS, INC.
- filed_at: 2022-06-02T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/872589/000110465922067375/0001104659-22-067375-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/872589/000110465922067375/tm2217255d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-22-067375
- JSON: https://secwatch.observer/filing/0001104659-22-067375.json
- Plain text: https://secwatch.observer/filing/0001104659-22-067375.txt

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