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what it is
Prothena is a biotech company trying to turn brain-disease research and partner deals into future drug revenue.
how it gets paid
Last year Prothena made $10M in revenue.
why growth slowed
Revenue fell 92.8% last year. The number is $10M. Revenue tripled in the quarter.
what just happened
Revenue reached $10M, but EPS fell to -$4.13, so the business is still living on milestones, not scale.
At a glance
B balance sheet — gets the job done, barely
15/100 earnings predictability — expect surprises
14.4% return on capital — nothing to write home about
-$4.53 fy2025 eps est
$2B fy2026 rev est
xvary composite: 39/100 — weak
What they do
Prothena is a biotech company trying to turn brain-disease research and partner deals into future drug revenue.
This company wins with science and partnerships, not current sales. It has 163 employees, just $6M of long-term debt, and collaborations with Roche and Bristol Myers Squibb. That gives you time and credibility while the pipeline tries to become a real business.
How they make money
$10M
annual revenue · revenue declined -92.8% last year
total revenue
$10M
92.8%
The products that matter
early-stage Alzheimer's antibody
PRX012
up to $2.2B option economics
this is the main asset now. it sits inside a Bristol-Myers Squibb option deal worth up to $2.2B, which tells you the upside is real and the dependency is even more real.
sole clinical focus
partnered ATTR cardiomyopathy asset
Coramitug (PRX004)
$50M milestone in mar 2026
Novo Nordisk paid a $50M milestone in March 2026. that's useful proof the pipeline still has value, but it is partnered out and not the asset carrying the equity story.
partnered asset
Key numbers
$2B
2026 revenue est
Forecast → expected future sales → so what. You are being asked to believe revenue can jump from $10M to $2B in about a year.
n/a
operating margin
Prior margin KPI failed sanity check — verify in filings. Operating margin → profit after running the business → so what. Prothena lost about $22 for every $1 of sales, which says today's revenue base is tiny.
$6M
long-term debt
Long-term debt → money owed over years → so what. Debt is only 1% of capital, so this story is about trial risk, not balance-sheet stress.
14.4%
return on capital
Return on capital → profit from invested money → so what. The number looks normal until you place it next to a n/a operating margin and remember biotech revenue is lumpy.
Financial health
B
strength
- balance sheet grade B — adequate — nothing special
- risk rank 4 — safer than 20% of stocks
- price stability 5 / 100
- long-term debt $6M (1% of capital)
B — functional but not a standout on the balance sheet.
Total return vs. market
Return history isn't available for PRTA right now.
source: institutional data · return history unavailable
What just happened
missed estimates
Revenue reached $10M, but EPS fell to -$4.13, so the business is still living on milestones, not scale.
Revenue rose 300% vs. prior year in the latest quarter, but annual revenue still fell 92.8% to $10M. That is classic biotech lumpiness: one payment shows up, then the income statement goes back to looking haunted.
$10M
revenue
$4.13
eps
100.0%
gross margin
the number that mattered
The number is $10M. Revenue tripled in the quarter, but the full business still only produced $10M over 12 months, which is tiny next to a $496M market cap.
source: company earnings report, 2026
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What could go wrong
the #1 risk is clinical failure or partner walkaway on PRX012. this is not a diversified pipeline story anymore.
med
PRX012 disappoints in early-stage data
The current bull case runs through one Alzheimer's antibody that is still early in development. If the biology disappoints, the $2.2B Bristol-Myers Squibb option economics stop looking like upside and start looking hypothetical.
This would hit the core valuation narrative directly, because the company already exited its prior lead program.
med
Cash burn stays too high for too long
Prothena burned $163.7M in 2025 against only $10M in revenue. Management has pointed to a lower $50M–$55M net cash use target for 2026, but the market will need to see it.
If burn stays elevated, the financing risk moves back to center stage and any pipeline upside gets discounted harder.
med
The business depends on larger pharmaceutical partners
Revenue is milestone-based and currently tiny. Bristol-Myers Squibb and Novo Nordisk matter because Prothena has no marketed products generating recurring sales of its own.
That means timing, economics, and strategic control are partly in other people's hands.
$10M of revenue against $163.7M of cash burn tells you the combined risk picture clearly: this stock needs clinical and partnership validation faster than it needs storytelling.
source: institutional data · regulatory filings · risk analysis
Pay attention to
calendar
Bristol-Myers Squibb's option posture on PRX012
The economics can reach $2.2B. Any signal that Bristol-Myers wants in — or does not — will move the entire debate about what PRTA is worth.
metric
2026 net cash use versus the $50M–$55M target
A move from $163.7M burn in 2025 to roughly $50M–$55M in 2026 would show the restructuring actually changed the math, not just the slide deck.
trend
PRX012 trial readouts
Because the company is now tightly focused, even early data trends matter. You are looking for evidence the asset is becoming more real, not just more discussed.
risk
Whether milestone revenue stays lumpy
The March 2026 $50M Novo milestone helped, but the base business still showed only $10M of annual revenue. Until product sales exist, volatility is part of the package.
Analyst rankings
earnings predictability
15 / 100
in human-speak, analysts do not have a stable operating model to work with because milestone revenue and trial timelines make the numbers jump.
risk rank
4
That means it is safer than only 20% of stocks in this framework. Translation: you should expect volatility, not smooth compounding.
source: institutional data
Institutional activity
institutional ownership data for PRTA is being compiled.
source: institutional data
Price targets
3-5 year target range
n/a
n/a
$9
current price
n/a
target midpoint · n/a from current
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