---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-113895"
form_type: "8-K"
ticker: "REGN"
cik: "0000872589"
company_name: "REGENERON PHARMACEUTICALS, INC."
filed_at: "2026-10-06T11:51:50+00:00"
generated_at: "2026-10-12T16:35:56.822669+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Regeneron, Sanofi expand antibody collaboration; Sanofi to pay $1B upfront, up to $7B in milestones

## Summary
- Sixth Amendment to 2009 Antibody LCA covers four new Regeneron antibodies: IL-13, IL-4, IL-4Rα, and IL-4xIL-13 bispecific.
- Sanofi to make $1.0B upfront payment; Regeneron eligible for up to $7.0B in development, regulatory, commercial milestones; global profits split 50/50.
- Regeneron gets option, per asset after ongoing trials, to add Sanofi's Phase 2/3 lunsekimig (TSLPxIL-13 Nanobody) and another early asset; would reimburse certain dev costs.
- Regeneron lead development and pre-approval regulatory party; lead US regulatory/commercialization; Sanofi leads commercialization and ex-US regulatory.
- Q3 2026 to include ~$22M pre-tax acquired IPR&D charge, cutting GAAP and non-GAAP EPS by ~$0.18; results not final. Dupixent audit lawsuit dismissed.

## SEC filing metadata
- accession: 0001104659-26-113895
- form_type: 8-K
- ticker: REGN
- cik: 0000872589
- company_name: REGENERON PHARMACEUTICALS, INC.
- filed_at: 2026-10-06T11:51:50+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 1.01, 2.02, 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/872589/000110465926113895/0001104659-26-113895-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/872589/000110465926113895/tm2627077d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-113895
- JSON: https://secwatch.observer/filing/0001104659-26-113895.json
- Plain text: https://secwatch.observer/filing/0001104659-26-113895.txt

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