---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-368288"
form_type: "8-K"
ticker: "LONA"
cik: "0001620463"
company_name: "LeonaBio, Inc."
filed_at: "2026-08-26T20:05:16+00:00"
generated_at: "2026-08-26T20:06:48.493199+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# LeonaBio enrolls 500th subject in Phase 3 ELAINE-3 trial; triggers warrant exercise

## Summary
- Enrolled 500th subject in Phase 3 ELAINE-3 trial (NCT05696626) for lasofoxifene + abemaciclib in ER+/HER2- ESR1-mutated metastatic breast cancer.
- Milestone triggers exercisability of 23,031,494 Series A Common Warrants at $6.35/share from Dec 2025 private placement.
- Full exercise would raise ~$146.2M; warrants expire 30 days after initial exercise date, no later than Nov 30, 2026.
- Warrants exercisable cash or cashless if resale registration unavailable; initial exercise date set as of Aug 26, 2026.

## SEC filing metadata
- accession: 0001193125-26-368288
- form_type: 8-K
- ticker: LONA
- cik: 0001620463
- company_name: LeonaBio, Inc.
- filed_at: 2026-08-26T20:05:16+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1620463/000119312526368288/0001193125-26-368288-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1620463/000119312526368288/lona-20260826.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-368288
- JSON: https://secwatch.observer/filing/0001193125-26-368288.json
- Plain text: https://secwatch.observer/filing/0001193125-26-368288.txt

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