Prothena’s fair value estimate has been nudged higher from $18.33 to $20.33 per share as analysts grow more confident in the company’s partnered pipeline and its potential to drive stronger long term revenue. The model now assumes faster top line expansion, with projected revenue growth raised from 74.7% to 90.9%, reflecting optimism around milestones, royalties, and expanding indications. Read on to see how this evolving narrative is reshaping expectations for Prothena and how you can stay aligned with future updates.
🐂 Bullish Takeaways
Piper Sandler reaffirmed its Overweight rating and more than doubled its price target on Prothena to $36 from $15, signaling increased conviction in the stock’s upside relative to current levels.
The firm highlights the value of Prothena’s partnered pipeline, pointing to potential income from net sales royalties and milestone payments as a key driver of long term growth momentum.
Piper Sandler describes the next 12+ months as catalyst rich, indicating confidence in Prothena’s execution on upcoming milestones and its ability to sustain revenue expansion that supports the higher valuation framework.
🐻 Bearish Takeaways
Even as Piper Sandler turns more positive on upside potential, the reliance on future milestones and royalties underscores ongoing execution and timing risks that could challenge the durability of the current valuation if key catalysts slip or underperform.
Do your thoughts align with the Bull or Bear Analysts? Perhaps you think there’s more to the story. Head to the Simply Wall St Community to discover more perspectives or begin writing your own Narrative!
NasdaqGS:PRTA Community Fair Values as at Dec 2025
Presented new preclinical data on CYTOPE, a novel drug delivery modality for cytosolic delivery of macromolecules to the brain and periphery, at Neuroscience 2025, highlighting its potential to target previously undruggable intracellular disease pathways.
Reported preclinical ALS results showing that systemically administered TDP 43 CYTOPE reached the brain, localized to intracellular pTDP 43 pathology, and significantly reduced pTDP 43 aggregates and associated RNA dysregulation in mouse models and human neuronal systems.
Announced publication of Phase 2 data for coramitug, a potential first in class amyloid depleter antibody for ATTR cardiomyopathy, in Circulation, with the results highlighted in a late breaking session at AHA Scientific Sessions 2025 and supporting its late stage cardiovascular franchise.
Highlighted advancement of coramitug into the Phase 3 CLEOPATTRA trial led by Novo Nordisk, under a collaboration that could deliver up to $1.2 billion in milestones for Prothena, including additional clinical milestone payments tied to enrollment targets.
Story Continues
Fair Value Estimate has risen modestly from $18.33 to $20.33 per share, reflecting higher long term revenue expectations from the partnered pipeline.
Discount Rate has increased slightly from 7.39% to 7.44%, indicating a marginally higher assumed risk profile in the valuation model.
Revenue Growth has been raised significantly from 74.7% to 90.9%, underscoring more optimistic assumptions for long term top line expansion.
Net Profit Margin has edged down from 17.0% to 16.0%, suggesting slightly more conservative expectations for long term profitability.
Future P/E multiple has been reduced from 112.7x to 101.7x, implying a somewhat lower valuation multiple despite the stronger growth outlook.
Narratives on Simply Wall St turn raw numbers into a clear, living story about a company. They connect Prothena’s science and strategy to explicit forecasts for revenue, earnings, and margins, and then to an estimated fair value. Hosted on the Community page used by millions of investors, Narratives make it easy to compare Fair Value with the current share price, consider potential entry or exit points, and stay in sync as news, clinical data, or earnings dynamically update the outlook.
Head over to the Simply Wall St Community and follow the Narrative on Prothena to stay on top of the story behind the latest fair value moves:
How pivotal readouts for birtamimab and Alzheimer’s assets could influence multi $bn opportunities and reshape long term forecasts.
What Prothena’s partnerships with BMS, Roche, and Novo Nordisk imply for potential future milestones, royalties, and earnings power.
Whether the consensus price target and assumed future P/E still stack up as fresh data and competitive risks emerge.
Read the full Prothena Narrative on Simply Wall St and consider whether the current price matches your view of its fair value.
Curious how numbers become stories that shape markets? Explore Community Narratives
This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.
Companies discussed in this article include PRTA.
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