---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-396654"
form_type: "8-K"
ticker: "LNTH"
cik: "0001521036"
company_name: "Lantheus Holdings, Inc."
filed_at: "2026-09-21T20:05:47+00:00"
generated_at: "2026-09-21T20:07:55.621017+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Lantheus/Curium refile HSR notice; new 30-day FTC review period ends Oct 21, 2026

## Summary
- Parent (Curium) withdrew HSR filing Sept 17, 2026; refiled Sept 21, starting new 30-day waiting period expiring Oct 21, 2026.
- Merger with Curium still expected to close in first half 2027, pending FTC approval, stockholder adoption, and other customary conditions.
- Parties continue working constructively with FTC staff; withdrawal/refiling described as routine to extend review time.
- Definitive proxy statement filed with SEC on Sept 8, 2026 for stockholder vote on the merger.

## SEC filing metadata
- accession: 0001193125-26-396654
- form_type: 8-K
- ticker: LNTH
- cik: 0001521036
- company_name: Lantheus Holdings, Inc.
- filed_at: 2026-09-21T20:05:47+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1521036/000119312526396654/0001193125-26-396654-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1521036/000119312526396654/d148743d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-396654
- JSON: https://secwatch.observer/filing/0001193125-26-396654.json
- Plain text: https://secwatch.observer/filing/0001193125-26-396654.txt

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