Prothena (PRTA) AI Stock Analysis

• Market Cap: $359.56M
• Dividend Yield: N/A
• Average Volume (3M): 1.36M
• Price to Earnings (P/E): ―
• Beta (1Y): 1.10
• Revenue Growth: 54.55%
• EPS Growth: 36.41%
• Country: US
• Employees: 163
• Sector: Healthcare
• Sector Strength: 41
• Industry: Biotechnology
• EPS (TTM): -1.12
• Shares Outstanding: 53,826,980
• 10 Day Avg. Volume: 754,660
• 30 Day Avg. Volume: 1,358,566
• PEG Ratio: -0.33
• Price to Book (P/B): 0.79
• Price to Sales (P/S): 0.00
• P/FCF Ratio: -2.65
• Enterprise Value/Market Cap: -0.17
• Enterprise Value/Revenue: -0.10
• Enterprise Value/Gross Profit: -0.78
• Enterprise Value/Ebitda: 0.12
• 1Y Price Target: $24.29
• Price Target Upside: 263.62% Upside
• Rating Consensus: Moderate Buy
• Number of Analyst Covering: 9

• Rating: 51 Neutral
• Price Target: $6.50 ▼(-2.69%Downside)

Prothena's overall stock score of 51 reflects a complex picture where financial struggles and valuation challenges weigh heavily, despite some technical stability and promising pipeline advancements. The discontinuation of birtamimab and workforce reductions underscore significant operational adjustments, while the Phase III progression of prasinezumab offers a potential upside, albeit with inherent risks.

Positive Factors

Alzheimer’s Treatment

PRX005’s MTBR-targeting MOA is supported by recent data as a promising approach for Alzheimer’s disease treatment, reinforcing tau pathology modulation.

Drug Development

PRX012 effectively impacts plaque clearance even at lower concentrations, with amyloid reduction being favorable while ARIA incidence remained consistent with placebo.

Therapeutic Potential

The decision to investigate 200 mg and 400 mg doses in a once-monthly regimen reflects confidence in PRX012’s therapeutic potential.

Negative Factors

Clinical Trial Results

Birtamimab did not show survival benefit in severe ALA.

Financial Strategy

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

Operational Changes

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, a late-stage clinical company, focuses on discovery and development of novel therapies for life-threatening diseases in the United States. The company is involved in developing Birtamimab, an investigational humanized antibody that is in Phase III clinical trial for the treatment of AL amyloidosis; Prasinezumab, a humanized monoclonal antibody, which is in Phase IIb clinical trial for the treatment of Parkinson's disease; PRX004 that completed Phase I clinical trial for the treatment of Transthyretin amyloidosis; and PRX005, which is in Phase I clinical trial for the treatment of Alzheimer's disease. Its discovery and preclinical programs include PRX012 for the treatment of Alzheimer's disease; and dual Aß-Tau vaccine for the treatment and prevention of Alzheimer's disease. Prothena Corporation plc has a license, development, and commercialization agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. to develop and commercialize antibodies that target alpha-synuclein; and a collaboration agreement with Bristol-Myers Squibb to develop antibodies. The company was founded in 2012 and is based in Dublin, Ireland.

How the Company Makes Money

Prothena primarily generates revenue through collaboration and licensing agreements with larger pharmaceutical companies, which may include upfront payments, milestone payments, and royalties on sales of products developed through these partnerships. Additionally, the company may earn income from government grants and other funding sources to support its research and development activities. As a clinical-stage company, Prothena does not yet generate revenue from product sales, as its pipeline candidates are still in various stages of clinical trials.

Prothena Financial Statement Overview

Summary

Prothena shows revenue growth but faces significant challenges with consistent losses and cash burn. The company maintains a strong equity position and cash reserves, but ongoing negative profitability metrics and cash flow issues present risks.

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	137.94M	135.16M	91.37M	53.91M	200.58M	853.00K
Gross Profit	79.51M	131.57M	-129.20M	47.16M	118.29M	-74.03M
EBITDA	-137.94M	-154.56M	-190.11M	-131.56M	71.97M	-111.22M
Net Income	-110.27M	-122.31M	-147.03M	-116.95M	66.97M	-111.14M
Balance Sheet
Total Assets	495.34M	547.11M	696.38M	758.03M	609.37M	332.98M
Cash, Cash Equivalents and Short-Term Investments	417.94M	471.39M	618.83M	710.41M	579.09M	295.38M
Total Debt	10.20M	10.84M	11.84M	6.47M	12.33M	17.84M
Total Liabilities	57.66M	60.18M	135.02M	135.99M	143.32M	148.97M
Stockholders Equity	437.68M	486.93M	561.37M	622.04M	466.04M	184.01M
Cash Flow
Free Cash Flow	-130.37M	-150.35M	-136.72M	-109.28M	92.03M	-80.56M
Operating Cash Flow	-130.36M	-150.05M	-133.91M	-108.82M	92.61M	-80.36M
Investing Cash Flow	-237.00K	-298.00K	-2.77M	-464.00K	-575.00K	-196.00K
Financing Cash Flow	670.00K	1.55M	45.10M	241.46M	190.33M	215.00K

Prothena Technical Analysis

• Technical Analysis Sentiment: Positive
• Last Price: 6.68
• 50DMA: Positive
• 100DMA: Negative
• 200DMA: Negative
• MACD: Negative
• RSI: Neutral
• STOCH: 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 6.68 is above the 20-day moving average (MA) of 6.41, above the 50-day MA of 6.00, and below the 200-day MA of 11.86, indicating a neutral trend. The MACD of 0.13 indicates Negative momentum. The RSI at 58.92 is Neutral, neither overbought nor oversold. The STOCH value of 70.94 is Neutral, 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
Sector *	60 Neutral	HK$16.95B	5.65	-7.44%	2.87%	11.55%	-28.15%
IMNM	52 Neutral	$945.82M	―	-69.21%	―	-13.76%	57.73%
PRTA	51 Neutral	$359.56M	―	-23.46%	―	54.55%	36.41%
BCAX	48 Neutral	$640.80M	―	34.94%	―	―	―
KALV	45 Neutral	$728.33M	―	-121.50%	―	―	-18.75%
REPL	42 Neutral	$242.82M	―	-62.58%	―	―	4.28%
RCKT	40 Underperform	$338.30M	―	-60.45%	―	―	6.99%

Prothena Corporate Events

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.