Prothena (PRTA) AI Stock Analysis

• Market Cap: $444.10M
• Dividend Yield: N/A
• Average Volume (3M): 973.45K
• Price to Earnings (P/E): ―
• Beta (1Y): 1.11
• Revenue Growth: -95.24%
• EPS Growth: -493.05%
• Country: US
• Employees: 163
• Sector: Healthcare
• Sector Strength: 50
• Industry: Biotechnology
• EPS (TTM): -2.34
• Shares Outstanding: 53,829,983
• 10 Day Avg. Volume: 1,303,734
• 30 Day Avg. Volume: 973,450
• PEG Ratio: N/A
• Price to Book (P/B): N/A
• Price to Sales (P/S): N/A
• P/FCF Ratio: N/A
• Enterprise Value/Market Cap: -0.08
• Enterprise Value/Revenue: -3.38
• Enterprise Value/Gross Profit: -3.70
• Enterprise Value/Ebitda: 0.14
• 1Y Price Target: $21.25
• Price Target Upside: 157.58% Upside
• Rating Consensus: Moderate Buy
• Number of Analyst Covering: 10

• Rating: 52 Neutral
• Price Target: $8.00 ▼(-3.03% Downside)

Prothena's overall stock score is primarily impacted by its financial instability, with declining revenue and negative profit margins. While technical indicators show some bullish momentum, the valuation remains unattractive due to negative earnings. Corporate events provide a mixed outlook, with promising drug advancements offset by operational challenges.

Positive Factors

Innovative Dosing Regimen

The company’s decision to evaluate 200 mg and 400 mg doses using a once-monthly regimen underscores confidence in PRX012’s potential and reflects a patient-friendly dosing model, particularly well-suited for subcutaneous administration in Alzheimer’s patients.

Strategic Partnership Potential

MAD data showing robust plaque reduction while maintaining lower ARIA rate can be encouraging for strategic partnership.

Therapeutic Potential of PRX012

Favorable amyloid plaque reduction was observed alongside ARIA rates comparable to placebo, suggesting that PRX012 can exert therapeutic effects at lower concentrations without exacerbating risk.

Negative Factors

Discontinuation of Birtamimab

PRTA is discontinuing development of birtamimab after it failed to significantly delay mortality significantly in the phase 3 AFFIRM-AL study.

Financial Implications

The discontinuation of birtamimab has led to a reduction in the price target from $30 to $14.

Operational Adjustments

The company said it will now work on reducing operating expenses that will include and won’t be limited to a substantial workforce reduction.

Prothena Business Overview & Revenue Model

Company Description

Prothena Corporation plc is a biotechnology company focused on discovering and developing novel therapeutics for the treatment of neurodegenerative diseases and cancer. The company leverages its expertise in protein misfolding and aggregation to create innovative therapies, primarily in the areas of amyloid-related diseases such as Alzheimer's and Parkinson's disease, along with other protein misfolding disorders. Prothena's pipeline includes several clinical-stage programs, highlighting its commitment to addressing unmet medical needs with its proprietary technology platform.

How the Company Makes Money

Prothena generates revenue through a combination of collaborations, licensing agreements, and potential milestone payments from its partnerships with pharmaceutical companies. The company enters into strategic alliances with larger biopharmaceutical firms that provide upfront payments and ongoing funding to support the development of its drug candidates. Additionally, Prothena may receive royalties on product sales if its partnered therapies reach the market. The company also has the potential for milestone payments as its candidates progress through various stages of clinical development, thereby contributing significantly to its earnings.

Prothena Financial Statement Overview

Summary

Prothena shows revenue growth, but persistent losses and cash burn are significant concerns. The company maintains a strong equity position and cash reserves, yet ongoing negative profitability metrics and cash flow issues present risks. Improving profitability is essential for long-term sustainability.

Income Statement

Prothena's revenue has shown growth over the years, with a notable increase from 2020 to 2025. However, the company is currently operating at a loss as evidenced by negative EBIT and net income. Gross profit margin is positive, indicating some operational efficiency, but the net profit margin is negative, highlighting ongoing profitability challenges.

Balance Sheet

The company's balance sheet shows a strong equity position with stockholders' equity significantly outweighing total debt, leading to a favorable debt-to-equity ratio. The equity ratio is high, indicating financial stability. However, the return on equity is negative due to persistent net losses, which is a concern for investors.

Cash Flow

Prothena's cash flow situation is challenging with negative operating and free cash flow, suggesting cash burn. The operating cash flow to net income ratio is negative due to ongoing losses, but the company has maintained a decent cash reserve, which provides some buffer.

Breakdown	TTM	Dec 2024	Dec 2023	Dec 2022	Dec 2021	Dec 2020
Income Statement
Total Revenue	10.34M	135.16M	91.37M	53.91M	200.58M	853.00K
Gross Profit	9.43M	135.16M	-129.20M	47.16M	118.29M	-74.03M
EBITDA	-248.10M	-154.56M	-190.11M	-131.56M	71.97M	-111.22M
Net Income	-302.92M	-122.31M	-147.03M	-116.95M	66.97M	-111.14M
Balance Sheet
Total Assets	399.07M	547.11M	696.38M	758.03M	609.37M	332.98M
Cash, Cash Equivalents and Short-Term Investments	371.44M	471.39M	618.83M	710.41M	579.09M	295.38M
Total Debt	9.78M	10.84M	11.84M	6.47M	12.33M	17.84M
Total Liabilities	74.73M	60.18M	135.02M	135.99M	143.32M	148.97M
Stockholders Equity	324.33M	486.93M	561.37M	622.04M	466.04M	184.01M
Cash Flow
Free Cash Flow	-196.69M	-150.35M	-136.72M	-109.28M	92.03M	-80.56M
Operating Cash Flow	-196.74M	-150.05M	-133.91M	-108.82M	92.61M	-80.36M
Investing Cash Flow	-184.94K	-298.00K	-2.77M	-464.00K	-575.00K	-196.00K
Financing Cash Flow	147.29K	1.55M	45.10M	241.46M	190.33M	215.00K

Prothena Technical Analysis

• Technical Analysis Sentiment: Positive
• Last Price: 8.25
• 50DMA: Positive
• 100DMA: Positive
• 200DMA: Negative
• MACD: Negative
• RSI: Negative
• STOCH: Negative

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 8.25 is above the 20-day moving average (MA) of 7.21, above the 50-day MA of 6.46, and below the 200-day MA of 11.17, indicating a neutral trend. The MACD of 0.44 indicates Negative momentum. The RSI at 75.06 is Negative, neither overbought nor oversold. The STOCH value of 93.18 is Negative, not indicating any strong overbought or oversold conditions. Overall, these indicators collectively point to a Positive sentiment for PRTA.

Prothena Peers Comparison

Name	Overall Rating	Market Cap	P/E Ratio	ROE	Dividend Yield	Revenue Growth	EPS Growth
PRTA	52 Neutral	$444.10M	―	-66.85%	―	-95.24%	-493.05%
IMNM	52 Neutral	$894.82M	―	-81.20%	―	16.74%	59.89%
Sector *	51 Neutral	$7.70B	-0.29	-46.01%	2.24%	23.07%	-0.65%
BCAX	48 Neutral	$635.11M	―	-32.71%	―	―	―
KALV	45 Neutral	$643.40M	―	-121.50%	―	―	-10.46%
REPL	42 Neutral	$433.99M	―	-73.44%	―	―	-1.07%
RCKT	40 Underperform	$329.11M	―	-69.65%	―	―	10.36%

Prothena Corporate Events

Prothena’s Coramitug Advances to Phase 3 with Novo Nordisk

On August 6, 2025, Prothena announced that its partner Novo Nordisk will advance coramitug, a potential first-in-class amyloid depleter antibody, into Phase 3 development for ATTR amyloidosis with cardiomyopathy. This decision follows the successful completion of a Phase 2 trial and is expected to commence in 2025. Prothena stands to earn a clinical milestone payment upon meeting specific enrollment criteria in the Phase 3 trial. The advancement of coramitug marks a significant step in addressing the unmet needs of patients with ATTR amyloidosis, potentially enhancing Prothena’s industry positioning and offering substantial financial benefits through its agreement with Novo Nordisk.

The most recent analyst rating on (PRTA) stock is a Buy with a $84.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Prothena Secures Leadership with New Executive Agreements

On July 30, 2025, Prothena Biosciences Inc entered into employment agreements with key executives, including the Chief Strategy Officer, Chief Operating Officer, and Chief Scientific Officer. These agreements outline their base salaries, bonus opportunities, and severance benefits, which align with the company’s existing severance plan. The agreements provide for enhanced severance benefits in the event of termination without cause or resignation for good reason, with further increases if such termination occurs in connection with a change in control. This move is likely to impact the company’s operations by securing leadership stability and potentially positioning the company more favorably in the industry.

The most recent analyst rating on (PRTA) stock is a Buy with a $48.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Prothena Announces Major Workforce Reduction to Cut Costs

On June 18, 2025, Prothena Corporation plc announced a significant reduction in its workforce by approximately 63% to cut operating costs and focus on its remaining wholly-owned programs and business development activities. This decision follows the company’s earlier announcement on May 23, 2025, to discontinue the development of birtamimab. The workforce reduction is expected to be completed by the end of the fourth quarter of 2025, with affected employees receiving severance packages. The company anticipates recognizing $16 to $20 million in severance and related benefits expenses. Additionally, the employment of Chief Regulatory Officer Carol D. Karp and Chief People Officer David A. Ford will terminate on August 1, 2025, as part of this reduction, triggering severance benefits and stock option adjustments.

The most recent analyst rating on (PRTA) stock is a Buy with a $84.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Prothena’s Prasinezumab Advances to Phase III for Parkinson’s

On June 15, 2025, Prothena Corporation announced that its partner Roche will advance prasinezumab into Phase III development for early-stage Parkinson’s disease. This decision follows data from the Phase IIb PADOVA study and ongoing open-label extensions, which suggest potential clinical benefits of prasinezumab, a first-in-class anti-alpha-synuclein antibody. The studies indicated positive trends towards reduced motor progression and provided biomarker evidence of prasinezumab’s impact on disease biology. This advancement could position prasinezumab as a potential disease-modifying treatment for Parkinson’s, addressing a significant unmet need for over 10 million affected individuals globally.

The most recent analyst rating on (PRTA) stock is a Buy with a $84.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Prothena Discontinues Birtamimab Development After Trial Failure

On May 23, 2025, Prothena Corporation announced that its Phase 3 AFFIRM-AL clinical trial for birtamimab in AL amyloidosis patients did not meet its primary or secondary endpoints, leading to the discontinuation of birtamimab’s development. As a result, Prothena plans to reduce operating expenses, including a significant workforce reduction, and will provide further updates in June. Despite the setback, Prothena remains focused on its other pipeline projects, including upcoming data from the Phase 1 ASCENT trials on PRX012 in Alzheimer’s disease and updates from its partners.

The most recent analyst rating on (PRTA) stock is a Buy with a $30.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.

Prothena Shareholders Approve Key Amendments at AGM

On May 13, 2025, Prothena Corporation plc held its annual general meeting where shareholders approved an amendment to the 2018 Long Term Incentive Plan, increasing the number of shares authorized for issuance by 2,000,000. Additionally, shareholders re-elected board members, ratified the appointment of KPMG LLP as the independent auditor for 2025, and approved executive compensation.

The most recent analyst rating on (PRTA) stock is a Buy with a $84.00 price target. To see the full list of analyst forecasts on Prothena stock, see the PRTA Stock Forecast page.