---
schema_version: "secwatch.filing_event.v1"
accession: "0001559053-24-000003"
form_type: "8-K"
ticker: "PRTA"
cik: "0001559053"
company_name: "PROTHENA CORP PUBLIC LTD CO"
filed_at: "2024-02-15T23:59:59+00:00"
generated_at: "2026-06-06T01:12:41.546631+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Prothena Q4 2023 net loss $67.5M; cash $621M; guides 2024 cash burn ~$208-225M

## Summary
- Net loss Q4 $67.5M ($1.26 loss per share) vs net income $6.3M Q4 2022; full year loss $147.0M.
- Total revenue Q4 $0.3M (vs $49.9M Q4 2022); full year $91.4M including $55M BMS milestone.
- Cash, equivalents & restricted cash $621M at Dec 31, 2023; no debt. 2024 cash use guidance $208-225M.
- Phase 1 PRX012 (Alzheimer's) data update expected 2024; partner BMS to advance BMS-986446 to Phase 2 in 1H2024.
- AFFIRM-AL birtamimab topline (Mayo Stage IV AL amyloidosis) expected between 4Q2024-2Q2025.

## SEC filing metadata
- accession: 0001559053-24-000003
- form_type: 8-K
- ticker: PRTA
- cik: 0001559053
- company_name: PROTHENA CORP PUBLIC LTD CO
- filed_at: 2024-02-15T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1559053/000155905324000003/0001559053-24-000003-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1559053/000155905324000003/prta-20240215.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001559053-24-000003
- JSON: https://secwatch.observer/filing/0001559053-24-000003.json
- Plain text: https://secwatch.observer/filing/0001559053-24-000003.txt

## Key facts
- Earnings Releases
  PROTHENA CORP PUBLIC LTD CO updated its the fourth quarter and fiscal year ended December 31, 2023 guidance (initiated).
  - Period: the fourth quarter and fiscal year ended December 31, 2023
  - Guidance: initiated
  - Result: reported results
  source text: On February 15, 2024, Prothena Corporation plc issued a press release announcing its financial results for the fourth quarter and fiscal year ended December 31, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1559053/000155905324000003/0001559053-24-000003-index.htm

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