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Prothena
(NASDAQ:PRTA)
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Rating:49Neutral
Price Target:
$10.00
▼(-8.26% Downside)
Action:Reiterated
Date:06/27/26
The score is primarily constrained by weak financial performance—persistent losses, negative TTM gross profit, and ongoing cash burn—despite a low-leverage balance sheet. Technicals are moderately supportive with the stock trading above major moving averages, but mixed momentum indicators limit conviction. Valuation is challenged by negative earnings and no dividend yield, while the recent corporate event is modestly positive for governance but not a fundamental catalyst.
Positive Factors
Low leverage balance sheet
Very low debt-to-equity (c.1%–5%) reduces refinancing and interest-rate risk, preserving financial optionality. For a clinical-stage biotech this supports continued R&D spending and the ability to fund trials or partnerships without immediate debt pressure, a durable strength over months.
Negative Factors
Persistent negative cash flow
Sustained negative operating and free cash flow since 2022 creates recurring funding needs. Over a 2–6 month horizon this heightens dilution or financing risk and constrains internal funding of multiple clinical programs absent consistent milestone receipts or partner financing.
Read all positive and negative factors
Positive Factors
Negative Factors
Low leverage balance sheet
Very low debt-to-equity (c.1%–5%) reduces refinancing and interest-rate risk, preserving financial optionality. For a clinical-stage biotech this supports continued R&D spending and the ability to fund trials or partnerships without immediate debt pressure, a durable strength over months.
Read all positive factors
Prothena Key Performance Indicators (KPIs)
Any
Revenue by Segment
Shows how much revenue each business segment generates, highlighting which parts of the company are driving growth and which may need strategic adjustments.
Shows how much revenue each business segment generates, highlighting which parts of the company are driving growth and which may need strategic adjustments.
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The Fly
The FlyProthena (PRTA) vs. SPDR S&P 500 ETF (SPY)
Market Cap
$507.30M
Dividend YieldN/A
Average Volume (3M)732.47K
Price to Earnings (P/E)―
Beta (1Y)0.98
Revenue Growth-57.99%
EPS Growth-37.06%
CountryUS
Employees67
SectorHealthcare
Sector Strength45
IndustryBiotechnology
Share Statistics
EPS (TTM)-2.81
Shares Outstanding52,353,237
10 Day Avg. Volume686,318
30 Day Avg. Volume732,465
Financial Highlights & Ratios
PEG Ratio-0.02
Price to Book (P/B)1.83
Price to Sales (P/S)53.08
P/FCF Ratio-3.14
Enterprise Value/Market Cap0.24
Enterprise Value/Revenue2.12
Enterprise Value/Gross Profit4.52
Enterprise Value/Ebitda-1.64
Forecast
1Y Price Target
$21.40Price Target Upside96.33% Upside
Rating ConsensusModerate Buy
Number of Analyst Covering5
EPS Forecast (FY)0.25
Revenue Forecast (FY)$87.90M
Prothena Business Overview & Revenue Model
Company Description
Prothena Corporation plc, a late-stage clinical biotechnology company, focuses on discovery and development of novel therapies to treat diseases caused by protein dysregulation. Its product pipeline includes Prasinezumab, an investigational humani...
How the Company Makes Money
Prothena generates revenue primarily through collaboration and licensing arrangements with larger biopharmaceutical partners rather than from product sales (it is a clinical-stage company). Under these agreements, Prothena typically earns (1) upfr...
Prothena Earnings Call Summary
Earnings Call Date:Feb 19, 2026
(Q4-2025)
| % Change Since: |
Next Earnings Date:Aug 10, 2026
Earnings Call Sentiment Positive
The call conveyed meaningful scientific and business progress — two partner programs advanced to Phase III, strong Phase II biomarker signals (40% reduction in a PD motor endpoint subset; 48% NT‑proBNP reduction for coramitug), introduction of a novel CYTOPE technology with encouraging preclinical TDP‑43 results, and a solid year‑end cash position ($308.4M). Material near‑term upside exists (up to $105M in 2026 milestones and ~ $3B in potential future milestones across partners). Offsetting risks include ARIA‑E safety concerns for PRX012 prompting re‑engineering, some non‑statistically significant secondary endpoints (6‑minute walk test), multi‑year timelines to Phase III primary completions (2029), continued net losses and burn, and reliance on partner decisions for key programs (PRX019). Overall, positives — pipeline advancement, strong partner validation, and a healthy cash balance — outweigh the operational and timing risks.Positive Updates
Two Partner Programs Advanced to Phase III
Roche advanced prasinezumab into the Phase III PARAISO trial (≈900 participants; primary completion expected in 2029). Novo Nordisk advanced coramitug into the Phase III CLEOPATTRA trial (≈1,280 patients; primary completion expected in 2029).
Negative Updates
ARIA‑E and Safety Profile Concerns for PRX012
PRX012 ASCENT reported ARIA‑E rates described as 'noncompetitive' relative to FDA‑approved anti‑Aβ antibodies, prompting a strategic pivot to a PRX012‑transferrin receptor (TfR) program to try to improve the ARIA profile.
Read all updates
Q4-2025 Updates
Positive
Negative
Two Partner Programs Advanced to Phase III
Roche advanced prasinezumab into the Phase III PARAISO trial (≈900 participants; primary completion expected in 2029). Novo Nordisk advanced coramitug into the Phase III CLEOPATTRA trial (≈1,280 patients; primary completion expected in 2029).
Read all positive updates
Company Guidance
Prothena's 2026 guidance calls for full‑year net cash used in operating and investing activities of $50–55 million, an estimated net loss of $67–72 million (which includes about $24 million of noncash share‑based compensation), and an expected year‑end cash, cash equivalents and restricted cash balance of approximately $255 million at the midpoint; this guidance does not include up to $105 million of potential aggregate clinical milestone payments from partners in 2026. For context, Prothena closed 2025 with $308.4 million in cash (as of Dec 31, 2025), reported 2025 net cash used in operating and investing activities of $163.7 million (favorable to prior guidance of $170–178 million), a 2025 net loss of $244.1 million (in line with guidance of $240–248 million), had 53.8 million ordinary shares outstanding as of Feb 12, 2026, and a simple capital structure with zero debt.Prothena Financial Statement Overview
Summary
Income Statement
28
Negative
Balance Sheet
72
Positive
Cash Flow
34
Negative
| Breakdown | TTM | Dec 2025 | Dec 2024 | Dec 2023 | Dec 2022 | Dec 2021 |
|---|---|---|---|---|---|---|
Income Statement | ||||||
| Total Revenue | 57.94M | 9.68M | 135.16M | 91.37M | 53.91M | 200.58M |
| Gross Profit | 27.14M | 5.98M | 135.16M | 91.37M | 53.91M | 200.58M |
| EBITDA | -74.72M | -197.13M | -128.04M | -159.55M | -124.86M | 73.04M |
| Net Income | -151.18M | -244.09M | -122.31M | -147.03M | -116.95M | 66.97M |
Balance Sheet | ||||||
| Total Assets | 349.89M | 326.80M | 547.11M | 696.38M | 758.03M | 609.37M |
| Cash, Cash Equivalents and Short-Term Investments | 329.46M | 307.53M | 471.39M | 618.83M | 710.41M | 579.09M |
| Total Debt | 7.65M | 13.86M | 10.84M | 11.84M | 6.47M | 12.33M |
| Total Liabilities | 37.28M | 46.33M | 60.18M | 135.02M | 135.99M | 143.32M |
| Stockholders Equity | 312.62M | 280.47M | 486.93M | 561.37M | 622.04M | 466.04M |
Cash Flow | ||||||
| Free Cash Flow | -81.44M | -163.72M | -150.35M | -136.72M | -109.28M | 92.03M |
| Operating Cash Flow | -81.34M | -163.58M | -150.05M | -133.91M | -108.82M | 92.61M |
| Investing Cash Flow | -96.00K | -138.00K | -298.00K | -2.77M | -464.00K | -575.00K |
| Financing Cash Flow | -7.04M | -139.00K | 1.55M | 45.10M | 241.46M | 190.33M |
Prothena Technical Analysis
Positive
10.90
Price Trends
9.70
Negative
9.60
Positive
9.69
Negative
Market Momentum
0.09
Negative
55.13
Neutral
70.26
Neutral
Evaluating momentum and price trends is crucial in stock analysis to make informed investment decisions. For PRTA, the sentiment is Positive. The current price of 10.9 is above the 20-day moving average (MA) of 8.99, above the 50-day MA of 9.70, and above the 200-day MA of 9.69, indicating a neutral trend. The MACD of 0.09 indicates Negative momentum. The RSI at 55.13 is Neutral, neither overbought nor oversold. The STOCH value of 70.26 is Neutral, not indicating any strong overbought or oversold conditions. Overall, these indicators collectively point to a Positive sentiment for PRTA.
Prothena Risk Analysis
Prothena disclosed 62 risk factors in its most recent earnings report. Prothena reported the most risks in the "Tech & Innovation" category.
Finance & Corporate - Financial and accounting risks. Risks related to the execution of corporate activity and strategy
Latest Risks Added 0 New Risks
Prothena Peers Comparison
UnderperformOutperform
Sector (51)
Name | Overall Rating | Market Cap | P/E Ratio | ROE | Dividend Yield | Revenue Growth | EPS Growth |
|---|---|---|---|---|---|---|---|
69 Neutral | $826.43M | 6.41 | 81.34% | ― | 201.29% | ― | |
68 Neutral | $760.19M | 26.06 | 30.21% | ― | 13.16% | ― | |
55 Neutral | $3.38B | -13.87 | -54.63% | ― | -51.68% | 69.60% | |
53 Neutral | $1.03B | -32.49 | -18.64% | ― | 123.12% | 86.10% | |
51 Neutral | $7.86B | -0.30 | -43.30% | 2.27% | 22.53% | -2.21% | |
49 Neutral | $507.30M | -3.45 | -49.88% | ― | -57.99% | -37.06% | |
49 Neutral | $1.28B | -27.69 | -38.92% | ― | ― | 17.91% |
* Healthcare Sector Average
PRTA
Prothena
9.69
3.26
50.58%
LXRX
Lexicon Pharmaceuticals
2.32
1.45
166.67%
XOMA
XOMA Royalty Corporation
43.00
16.04
59.50%
ZVRA
Zevra Therapeutics
13.98
4.24
43.53%
CRVS
Corvus Pharmaceuticals
15.23
11.28
285.57%
ALMS
Alumis Inc.
26.50
23.10
679.41%
Prothena Corporate Events
Executive/Board ChangesShareholder Meetings
Prothena Shareholders Reaffirm Board, Auditor and Pay Policies
Positive
May 15, 2026
On May 14, 2026, Prothena shareholders re-elected directors Shane M. Cooke and Dennis J. Selkoe to the board to serve until no later than the 2029 annual general meeting, affirming the company’s existing leadership structure and governance c...
Glossary
BuyA stock rated as a "Buy" is expected to perform better than the overall market or a specific benchmark over the near-to-medium term. This rating suggests the stock is likely to deliver higher returns compared to other stocks in the same sector or market index. Note: This is not investment advice; please consult a financial advisor before making investment decisions.
HoldA stock rated as a "Hold" is expected to perform in line with the overall market or a specific benchmark. This rating indicates that the stock is neither particularly compelling nor unfavorable for investment. Note: This is not investment advice; please consult a financial advisor before making investment decisions.
SellA stock rated as a "Sell" is expected to perform worse than the overall market or a specific benchmark over the near-to-medium term. This rating suggests the stock may deliver lower returns compared to other stocks in the same sector or market index. Note: This is not investment advice; please consult a financial advisor before making investment decisions.
Disclaimer
This AI Analyst Stock Report is automatically generated by our AI systems using advanced algorithms and publicly available financial, technical, and market data. While the information provided aims to be accurate and insightful, it is intended for informational purposes only and should not be considered financial advice. Any content created by an AI (Artificial Intelligence) system may contain inaccuracies and/or contain errors. Investing in stocks carries inherent risks, and past performance is not indicative of future results. This report does not account for your personal financial circumstances, objectives, or risk tolerance. Always conduct your own research or consult with a qualified financial advisor before making investment decisions. The analysis and recommendations provided are based on historical and current data and may not fully reflect future market conditions or unexpected developments. Neither the creators of this report nor its affiliated entities guarantee the accuracy, completeness, or reliability of the information presented. Use this report at your own discretion and risk.