---
schema_version: "secwatch.filing_event.v1"
accession: "0001559053-25-000022"
form_type: "8-K"
ticker: "PRTA"
cik: "0001559053"
company_name: "PROTHENA CORP PUBLIC LTD CO"
filed_at: "2025-05-08T23:59:59+00:00"
generated_at: "2026-05-22T04:17:06.084486+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Prothena Q1 net loss $60.2M, cash $418.8M; AFFIRM-AL data due Q2 2025

## Summary
- Net loss $60.2M ($1.12/share) vs $72.2M ($1.34/share) year ago; revenue $2.8M (from BMS collaboration).
- Cash $418.8M at quarter end; FY2025 net cash burn guidance $168-175M, ending cash ~$301M.
- Phase 3 AFFIRM-AL (birtamimab) topline results expected Q2 2025; SPA with FDA, primary endpoint all-cause mortality.
- Multiple PRX012 Phase 1 readouts expected from mid-2025; Roche to decide prasinezumab next steps mid-year.
- Novo Nordisk's coramitug Phase 2 for ATTR-CM completes enrollment; results expected H2 2025.

## SEC filing metadata
- accession: 0001559053-25-000022
- form_type: 8-K
- ticker: PRTA
- cik: 0001559053
- company_name: PROTHENA CORP PUBLIC LTD CO
- filed_at: 2025-05-08T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1559053/000155905325000022/0001559053-25-000022-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1559053/000155905325000022/prta-20250508.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001559053-25-000022
- JSON: https://secwatch.observer/filing/0001559053-25-000022.json
- Plain text: https://secwatch.observer/filing/0001559053-25-000022.txt

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