PROTHENA CORP PUBLIC LTD CO
PRTA evidence brief
What we can confirm
- BioSniper Score:
- 8.9 / 10
- Market Cap:
- $489.8M
- Lead Asset:
- Birtamimab (Phase 3)
What it means
What to watch
Prepared research question
What matters most for PRTA—catalysts, financial risk and supporting evidence?
Traceable citations · Unknowns marked
BioSniper AI · PRTA
PROTHENA CORP PUBLIC LTD CO (PRTA) is a clinical-stage biopharmaceutical company focused on developing therapeutics for neurodegenerative and rare peripheral amyloid diseases, with a pipeline including partnered Phase 3 programs and a restructured wholly-owned portfolio.
Key risk: Program discontinuation risk
BioSniper Score
Based on 4 of 6 signals
Market Cap
$489.8M
Cash Runway
—
Lead Asset
Birtamimab (Phase 3)
Next Catalyst
—
Financial data as of Jun 30, 2026.
Tracking 4 pipeline candidates · 8 clinical trials for PROTHENA CORP PUBLIC LTD CO.
Similar companies
PROTHENA CORP PUBLIC LTD CO (PRTA) is a clinical-stage biopharmaceutical company focused on developing therapeutics for neurodegenerative and rare peripheral amyloid diseases, with a pipeline including partnered Phase 3 programs and a restructured wholly-owned portfolio.
- Cash & equivalents of $288.2M as of 2026-06-30 [sec].
- Total revenue of $1.0M and net income of -$18.6M as of 2026-06-30 [sec].
- Shareholders' equity of $286.9M as of 2026-06-30 [sec].
- Roche initiated Phase 3 PARAISO trial for prasinezumab in Parkinson's disease in 2025; primary completion expected in 2029 [sec · filed 2026-03-27].
- Novo Nordisk initiated Phase 3 CLEOPATTRA trial for coramitug in ATTR cardiomyopathy in 2025; primary completion expected in 2029 [sec · filed 2026-03-27].
What works
- Partnered Phase 3 programs with Roche (prasinezumab) and Novo Nordisk (coramitug) provide external validation and financial support [sec · filed 2026-03-27].
- Cash position of $288.2M as of 2026-06-30 provides runway for ongoing operations and partnered trials [sec].
- Prasinezumab has been described by Roche as having peak sales potential greater than $3.5 billion and could be the first disease-modifying treatment for Parkinson's disease [sec · filed 2026-03-27].
What to weigh
- The Phase 3 AFFIRM-AL trial for birtamimab did not meet primary or secondary endpoints, leading to discontinuation of the program and a 63% workforce reduction [sec · filed 2026-03-27].
- Total revenue is minimal ($1.0M as of 2026-06-30) and net income is negative (-$18.6M), reflecting the pre-revenue stage and restructuring costs [sec].
- The company's future depends heavily on the success of partnered programs (prasinezumab, coramitug) over which it has limited control [sec · filed 2026-03-27].
- Forward-looking statements in SEC filings highlight numerous risks and uncertainties that could cause actual results to differ materially from expectations [sec_mda · as of 2026-08-06].
From the filings
Quoted directly from source documents.
Birtamimab Phase 3 trial failed and program discontinued
“the trial did not meet its primary or secondary endpoints and, as such, we subsequently discontinued the development of birtamimab and in June we commenced a corporate restructuring, including an approximate 63% reduction in workforce”
SEC filings · March 27, 2026
Roche initiated Phase 3 PARAISO trial for prasinezumab
“In 2025, Roche initiated the Phase 3 PARAISO clinical trial in approximately 900 participants with early-stage Parkinson's disease; primary completion is expected in 2029.”
SEC filings · March 27, 2026
Novo Nordisk initiated Phase 3 CLEOPATTRA trial for coramitug
“In 2025, Novo Nordisk initiated the Phase 3 CLEOPATTRA clinical trial in approximately 1,280 participants with ATTR amyloidosis with cardiomyopathy; primary completion is expected in 2029.”
SEC filings · March 27, 2026
Risks & what to watch (4)›
Key risks
- Program discontinuation risk — Wholly-owned pipeline reduced after birtamimab failure; reliance on partnered programs [sec · filed 2026-03-27].
- Minimal revenue, ongoing losses — Revenue of $1.0M and net loss of $18.6M as of 2026-06-30; pre-revenue stage [sec].
- Dependence on partners — Key programs (prasinezumab, coramitug) are controlled by Roche and Novo Nordisk [sec · filed 2026-03-27].
- Clinical trial uncertainties — Phase 3 trials for prasinezumab and coramitug have primary completion in 2029; long timeline [sec · filed 2026-03-27].
What to watch
- Progress and interim data from Roche's Phase 3 PARAISO trial for prasinezumab (primary completion 2029) [sec · filed 2026-03-27].
- Progress and interim data from Novo Nordisk's Phase 3 CLEOPATTRA trial for coramitug (primary completion 2029) [sec · filed 2026-03-27].
- Cash burn rate and any further restructuring or cost-reduction measures following the 63% workforce reduction [sec · filed 2026-03-27].
- Potential new wholly-owned pipeline candidates or business development moves to replace discontinued birtamimab program [sec · filed 2026-03-27].
Sources: Catalysts · Pipeline · SEC filings · SEC MD&A · Generated October 11, 2026 · How we verify sources →
Run PROTHENA CORP PUBLIC LTD CO through your own thesis
Use the pipeline, catalyst, financial, FDA, and market facts on this page as inputs to a protocol you control.
Your protocol can:
- Turn available PROTHENA CORP PUBLIC LTD CO facts into screen rules or deeper checks
- Show cited findings, blockers, and unresolved evidence together
- Save the logic and rerun it as the company evidence changes
Evidence & data
Score breakdownBased on 4 of 6 signals · derived from public data
Cash runway data unavailable
D/E 0.05 · 0% dilution
Lead: Phase 3
4 candidates
No upcoming catalysts tracked
8 buys · 2 sells (180d)
Pipeline
Regulatory
Financials
Institutional Holdings
Source: SEC Form 13F · as of Mar 2026Institutional holders
184
Total value held
$439.3M
| Holder | Shares | Value |
|---|---|---|
| fmr llc | 7,551,218 | $73.4M |
| rubric capital management lp | 5,000,000 | $48.6M |
| blackrock, inc. | 4,644,160 | $45.1M |
| state street corp | 1,938,498 | $18.8M |
| d. e. shaw & co., inc. | 1,763,347 | $17.1M |
| adar1 capital management, llc | 1,581,443 | $15.4M |
| vanguard portfolio management llc | 1,445,979 | $14.1M |
| morgan stanley | 1,230,448 | $12.0M |
| palo alto investors lp | 1,208,568 | $11.7M |
| two sigma investments, lp | 1,205,978 | $11.7M |
Showing top 10 of 184 institutional holders of PROTHENA CORP PUBLIC LTD CO. Open the full 13F history after sign-in.
Short Interest
as of Apr 28, 2026- % of float
- 15.7%
- Days to cover
- 13.5
- Shares short
- 7,076,832
- Daily short volume
- -
Short percent of float and days-to-cover reflect reported short positioning. Daily short volume is the exchange-reported short share of a single day's trading volume and is noisier. See the most-shorted biotech ranking →
PRTA short interestGovernance
Frequently asked questions
What is the AI investment thesis for PROTHENA CORP PUBLIC LTD CO?
PROTHENA CORP PUBLIC LTD CO (PRTA) is a clinical-stage biopharmaceutical company focused on developing therapeutics for neurodegenerative and rare peripheral amyloid diseases, with a pipeline including partnered Phase 3 programs and a restructured wholly-owned portfolio.
What is PROTHENA CORP PUBLIC LTD CO's lead drug candidate?
PROTHENA CORP PUBLIC LTD CO's most advanced tracked candidate is Birtamimab (Phase 3) for Light Chain (AL) Amyloidosis.
Who is the CEO of PROTHENA CORP PUBLIC LTD CO?
Dr. Gene G. Kinney Ph.D. is the chief executive officer of PROTHENA CORP PUBLIC LTD CO (PRTA).
Where is PROTHENA CORP PUBLIC LTD CO headquartered?
PROTHENA CORP PUBLIC LTD CO (PRTA) is headquartered in Dublin, Ireland.
What therapeutic areas does PROTHENA CORP PUBLIC LTD CO focus on?
PROTHENA CORP PUBLIC LTD CO develops therapies across Oncology, Neurology, Pain, Dermatology.
The AI overview and BioSniper Score are neutral, data-derived signals built from public SEC filings, ClinicalTrials.gov and FDA records — not investment advice.