Key Takeaways Prothena reported a Q4 loss of 45 cents per share, while revenues fell sharply year over year.Prothena expects 2026 net cash burn of $50M-$55M and projects up to $105M in milestone payments.Prothena's partnered pipeline includes late-stage studies with Roche and Novo Nordisk through 2029.Prothena Corporation (PRTA) reported fourth-quarter 2025 adjusted loss per share (excluding restructuring costs) of 45 cents, in line with the Zacks Consensus Estimate.In the year-ago quarter, the company had ...

Core Insights - Prothena reported a quarterly loss of $0.44 per share, slightly better than the Zacks Consensus Estimate of a loss of $0.45, and an improvement from a loss of $1.08 per share a year ago, resulting in an earnings surprise of +1.12% [1] - The company generated revenues of $0.02 million for the quarter ended December 2025, missing the Zacks Consensus Estimate by 99.3%, and a significant decline from year-ago revenues of $2.12 million [2] - Prothena's stock has underperformed, losing about 4.8% since the beginning of the year, while the S&P 500 has gained 0.5% [3] Earnings Outlook - The future performance of Prothena's stock will largely depend on management's commentary during the earnings call and the company's earnings outlook, including current consensus earnings expectations for upcoming quarters [4] - The estimate revisions trend for Prothena was mixed ahead of the earnings release, resulting in a Zacks Rank 3 (Hold), indicating expected performance in line with the market [6] - Current consensus EPS estimate for the next quarter is -$0.39 on $5 million in revenues, and for the current fiscal year, it is $0.20 on $148.76 million in revenues [7] Industry Context - The Medical - Biomedical and Genetics industry, to which Prothena belongs, is currently in the top 36% of over 250 Zacks industries, suggesting a favorable outlook compared to lower-ranked industries [8] - Compugen, another company in the same industry, is expected to report quarterly earnings of $0.05 per share, reflecting a year-over-year change of +171.4%, with revenues anticipated to be $17.87 million, up 1115.7% from the previous year [9]

Prothena (NasdaqGS:PRTA) Q4 2025 Earnings call February 19, 2026 04:30 PM ET Company ParticipantsAlexa Deemer - Biotechnology Equity Research AssociateBrandon Smith - COOChad Swanson - Chief Development OfficerGene Kinney - President and CEOMark Johnson - VP and Head of Investor RelationsNevin Jacob - Associate in Equity ResearchPhil Dolan - VP of Discovery ResearchTran Nguyen - Chief Strategy Officer and CFOConference Call ParticipantsJason Butler - Managing Director and Senior Biotechnology Equity Researc ...

Prothena (NasdaqGS:PRTA) Q4 2025 Earnings call February 19, 2026 04:30 PM ET Company ParticipantsAlexa Deemer - Biotechnology Equity Research AssociateBrandon Smith - COOChad Swanson - Chief Development OfficerGene Kinney - President and CEOMark Johnson - VP and Head of Investor RelationsNevin Jacob - Associate in Equity ResearchPhil Dolan - VP and Head of Discovery ResearchTran Nguyen - Chief Strategy Officer and CFOConference Call ParticipantsJason Butler - Managing Director and Senior Biotechnology Equit ...

Prothena (NasdaqGS:PRTA) Q4 2025 Earnings call February 19, 2026 04:30 PM ET Speaker4Thank you for your patience. Prothena Biosciences fourth quarter and full year 2025 financial results call will begin in approximately five minutes. Again, thank you for standing by. Good day, ladies and gentlemen, and welcome to the Prothena Biosciences fourth quarter and full year 2025 financial results conference call. My name is Jeannie, and I will be your coordinator for today. At this time, all participants are in a l ...

Prothena Fourth Quarter and Year-End 2025 Financial Results 4Q and FY25 Earnings Call Agenda | Welcome | Mark Johnson Vice President, Head of Investor Relations | | --- | --- | | Opening Remarks | Gene Kinney, Ph.D. President and CEO | | Clinical Programs | Chad Swanson, Ph.D. Chief Development Officer | | Preclinical Programs | Philip Dolan, Ph.D. Vice President, Head of Discovery Research | | Financial Results | Tran Nguyen Chief Strategy Officer and Chief Financial Officer | | Closing Remarks | Gene Kinn ...

Exhibit 99.1 PRESS RELEASE Prothena Reports Fourth Quarter and Full Year 2025 Financial Results, and Provides Financial Guidance and Business Highlights DUBLIN, Ireland, February 19, 2026-- Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today reported financial results for the fourth quarter and full year 2025. In addition, the Company provided business highlights and 2026 fi ...

Core Viewpoint - Prothena Corporation (PRTA) has experienced a significant decline in share price, dropping 36.8% over the past year, primarily due to setbacks in its pipeline, particularly the failure of its candidate birtamimab in a late-stage study [1][6]. Financial Performance - The company has reported inconsistent earnings over the last four quarters, with losses widening due to increased research and development expenses and the impact of pipeline setbacks, including the discontinuation of birtamimab [2]. - Prothena's earnings have missed estimates in each of the last four quarters, with an average negative surprise of 26.72% [2]. Pipeline Setbacks - In May 2025, Prothena announced the discontinuation of birtamimab after the AFFIRM-AL study failed to meet its primary endpoint, removing a near-term value driver [3]. - The termination of birtamimab has significantly reduced near-term catalysts for the stock and shifted the company's strategic focus toward earlier-stage assets like PRX012, which are several years away from potential commercialization [4]. Workforce and Cost Management - In June, Prothena announced a 63% workforce reduction to streamline operating costs while ensuring continued support for its wholly owned programs and partnered program obligations [7]. Partnered Programs Progress - Prothena's pipeline progress is largely driven by partnered assets rather than wholly owned programs [8]. - Partner Novo Nordisk is evaluating coramitug in the phase III CLEOPATTRA program for ATTR cardiomyopathy, which could earn Prothena up to $1.23 billion in development and sales milestones [9]. - Roche has initiated the phase III PARAISO study on prasinezumab for early-stage Parkinson's disease, indicating ongoing commitment to this collaboration [10]. Collaboration Agreements - Prothena has a worldwide collaboration agreement with Roche, having received $135 million to date, with potential for up to $620 million in additional milestone payments and royalties on future sales [11]. - Bristol Myers Squibb is conducting a phase II study for its anti-tau antibody BMS-986446 in Alzheimer's disease, with primary completion expected in 2027 [12]. Ongoing Development - Prothena has initiated an early-stage first-in-human study on PRX019, with completion expected in 2026 [14].

Core Viewpoint - Prothena (PRTA) has received a Zacks Rank 2 (Buy) upgrade, indicating a positive outlook for its earnings estimates, which is a significant factor influencing stock prices [1][3]. Earnings Estimates and Stock Price Movement - The Zacks rating system emphasizes the correlation between changes in earnings estimates and stock price movements, driven by institutional investors who adjust their valuations based on these estimates [4]. - An increase in earnings estimates typically leads to higher fair value for a stock, prompting institutional investors to buy or sell, which subsequently affects stock prices [4]. Prothena's Earnings Outlook - Prothena is projected to earn -$4.60 per share for the fiscal year ending December 2025, which remains unchanged from the previous year [8]. - Over the past three months, the Zacks Consensus Estimate for Prothena has increased by 119%, reflecting a positive trend in earnings estimates [8]. Zacks Rank System - The Zacks Rank system classifies stocks into five groups based on earnings estimates, with Zacks Rank 1 (Strong Buy) stocks historically generating an average annual return of +25% since 1988 [7]. - Prothena's upgrade to Zacks Rank 2 places it in the top 20% of Zacks-covered stocks, indicating strong potential for market-beating returns in the near term [10].

Core Insights - Prothena Corporation plc announced the resignation of Paula Cobb from its Board of Directors as she will join Manifold Bio as Chief Operating Officer, marking a significant transition for the company [1][2] - Cobb has been a part of Prothena's board for six years, contributing to the company's vision and strategy, and her departure leaves the board with 8 directors [2] Company Overview - Prothena is a late-stage clinical biotechnology company specializing in protein dysregulation, with a pipeline of investigational therapeutics aimed at treating neurodegenerative and rare peripheral amyloid diseases [3] - The company leverages decades of scientific research to advance therapeutic candidates for various indications, including ATTR amyloidosis with cardiomyopathy, Alzheimer's disease, and Parkinson's disease [3]