Prothena Corporation plc

PRTA

Prothena Corporation plc is a late-stage clinical biotechnology company focused on the discovery and development of novel therapeutics for neurodegenerative and rare peripheral amyloid diseases. The company develops antibody-based treatments targeting pathogenic proteins such as alpha-synuclein, transthyretin, tau, and amyloid beta. Its pipeline includes prasinezumab for Parkinson’s disease, coramitug for transthyretin amyloidosis with cardiomyopathy, BMS-986446 for Alzheimer’s disease, and PRX019 for amyotrophic lateral sclerosis. Prothena utilizes its proprietary CYTOPE technology to target intracellular disease pathways in the brain and periphery. The company partners with major pharmaceutical firms including Roche, Novo Nordisk, and Bristol Myers Squibb for the clinical development of its candidates. Established in 2012 following its separation from Elan Corporation, Prothena leverages scientific expertise inherited from Athena Neurosciences, which was founded in 1986. Summarised from the company's own disclosures, fiscal year ended Feb 2026	Industry Biotechnology	Homepage prothena.com
	Sector Healthcare	IR page ir.prothena.com/overview/default.aspx
	Tags neurodegenerative diseases, amyloidosis, antibody therapeutics, protein dysregulation, parkinson's disease, alzheimer's disease, amyotrophic lateral sclerosis, transthyretin amyloidosis, clinical-stage, cytope technology, prasinezumab, coramitug, BMS-986446, PRX019, PRX012, CYTOPE, PARAISO, CLEOPATTRA, TargetTau-1, Athena Neurosciences, Tysabri, natalizumab	Press page —

Metrics

Valuation
Market cap	$ 414.348M
P/E	-6.31
P/BV	1.54
P/S	7.86
P/OCF	-13.18
P/FCF	-2.53
Dividend yield	—
Turnover / mcap	—

Returns
ROE	-63.6%
ROI	—
ROIC	—
Profit margin	-2,520.6%

Growth
Revenue growing	No
Profits growing	No
Revenue up 3y	No
Revenue up 5y	No

Quality
Profitable	No
Margin expanding	No
Buying back stock	No
Diluting (TTM)	No
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News sentiment (TTM)	15
Quality score	-66.7%

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Figure	FY 2025	FY 2024	FY 2023	FY 2022	FY 2021	FY 2020	FY 2019	FY 2018	FY 2017	FY 2016	FY 2015	FY 2014	FY 2013	FY 2012
Revenue	9.684M	135.157M	91.37M	53.905M	200.577M	853K	814K	955K	27.519M	1.055M	1.607M	50.854M	—	—
Free cash flow	-163.718M	-150.348M	-136.716M	-109.285M	92.03M	—	—	—	—	—	—	—	—	—

Figure	FY 2025	FY 2024	FY 2023	FY 2022	FY 2021	FY 2020	FY 2019	FY 2018	FY 2017	FY 2016	FY 2015	FY 2014	FY 2013	FY 2012
Share price	9.55	13.85	36.34	60.25	49.4	12.01	15.83	10.3	37.49	49.19	68.11	20.76	26.52	—
Price performance 12m	-0.31	-0.62	-0.4	0.22	3.11	-0.24	0.54	-0.73	-0.24	-0.28	2.28	-0.22	—	—

Podcast Mentions

2026-11-05 Prothena Reports Third Quarter 2026 Financial Results and Business Highlights

•Net cash used in operating and investing activities was $12.0 million in the third quarter and net cash used in operating and investing activities was $8.9 million for the first nine months of 2026; quarter-end cash and restricted cash position was $272.2 million

•Novo recently presented post hoc analyses at the Heart Failure Society of America (HFSA) Annual Scientific Meeting from the coramitug Phase 2 trial which demonstrated a decrease of the inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) in patients treated with coramitug as compared to an increase in patients on placebo, further supporting the potential of coramitug as a treatment for ATTR-CM

•Multiple research collaborations with industry partners ongoing to explore the potential of our CYTOPE® technology over the next 12 to 24 months

DUBLIN, Ireland, November 5, 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 third quarter and first nine months of 2026 and provided business highlights.

Original on sec.gov

2026-10-28 Prothena Corporation plc — Termination of a Material Definitive Agreement Bull 0 Bear 7 Clinical/regulatory

Following an internal strategic review, Bristol Myers Squibb informed Prothena Corporation plc (the “Company”) on October 28, 2026 that it has decided not to advance PRX019 further in the clinic. In May 2024, a subsidiary of the Company entered into an exclusive global license agreement for PRX019 with Bristol Myers Squibb (the “PRX019 Global License Agreement”) to develop, manufacture and commercialize antibody products globally targeting a specified target (including PRX019, and collectively, “Licensed Products”) for any and all uses or purposes with respect to any human or animal disease, disorder or condition, and received an upfront payment of $80 million. The PRX019 License Agreement will terminate on January 28, 2027.

In the first half of 2026, the Company completed the Phase 1 trial for PRX019, which successfully demonstrated a benign safety and tolerability profile, no immunogenicity, and dose-dependent pharmacokinetics and pharmacodynamic effects, meeting the Company’s prespecified pharmacodynamic targets.

Original on sec.gov

2026-08-06 Prothena Reports Second Quarter 2026 Financial Results and Business Highlights Bull 5 Bear 0 Results

•Net cash used in operating and investing activities was $25.7 million in the second quarter, and net cash provided by operating and investing activities was $3.2 million for the first six months of 2026; quarter-end cash and restricted cash position was $289.1 million

•Guidance updated to include shares repurchased through July 30, 2026 and now expects to end the year with approximately $259 million (midpoint) in cash, cash equivalents and restricted cash

•Results from partner Roche evaluating prasinezumab in patients with early Parkinson’s disease from the Phase 2b PADOVA clinical trial published in The Lancet

•Multiple research collaborations with industry partners ongoing to explore the potential of our CYTOPE® technology over the next 12 to 24 months

DUBLIN, Ireland, August 6, 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 second quarter and first six months of 2026 and provided business highlights.

Original on sec.gov

2026-05-07 Prothena Reports First Quarter 2026 Financial Results and Business Highlights Bull 6 Bear 0 Results

•Net cash provided by operating and investing activities was $28.9 million for the first quarter of 2026; quarter-end cash and restricted cash position was $330.3 million

•Prothena updates projected full year 2026 net cash used in operating and investing actives to be $18 to $23 million (versus prior guidance $50 to $55 million) and expects to end the year with approximately $273 million (midpoint) in cash, cash equivalents and restricted cash

•Novo Nordisk obtained Fast Track designation from the U.S. FDA for coramitug (PRX004) for the treatment of ATTR amyloidosis with cardiomyopathy and paid Prothena a $50 million clinical milestone payment related to Phase 3 enrollment

•Roche presented several clinical updates supporting the potential of prasinezumab for the treatment of Parkinson’s disease at the International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders (AD/PD™ 2026)

•Prothena has completed the Phase 1 study for PRX019.

Original on sec.gov

2026-02-27 Prothena Announces up to $100 Million Share Repurchase Plan Bull 3 Bear 0 Capital return

DUBLIN, Ireland, February 27, 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 announced that its Board of Directors has authorized a Share Repurchase Plan under which the Company may repurchase up to $100.0 million of the Company’s outstanding ordinary shares, par value $0.01 per share.

Prothena had cash, cash equivalents and restricted cash of $308.4 million and no debt as of December 31, 2025. Excluding any potential purchases under this Share Repurchase Plan, Prothena expects to end the year with approximately $255 million in cash, cash equivalents, and restricted cash. This financial guidance does not include the potential to earn up to $105 million of aggregate clinical milestone payments from strategic partners in 2026 related to the advancement of both coramitug for ATTR amyloidosis with cardiomyopathy by Novo Nordisk and PRX019 for neurodegenerative diseases by Bristol Myers Squibb.

Original on sec.gov

2026-02-19 Prothena Reports Fourth Quarter and Full Year 2025 Financial Results, and Provides Financial Guidance and Business Highlights Bull 3 Bear 4 Results

•Net cash used in operating and investing activities was $23.3 million and $163.7 million for the fourth quarter and full year of 2025, respectively; quarter-end cash and restricted cash position was $308.4 million

•Prothena expects the full year 2026 net cash used in operating and investing activities to be $50 to $55 million and expects to end the year with approximately $255 million in cash (midpoint). Financial guidance does not include the potential to earn up to $105 million in aggregate clinical milestone payments from strategic partners in 2026

•Roche initiated the Phase 3 PARAISO trial evaluating prasinezumab in early-stage Parkinson’s disease in 4Q 2025; primary completion expected in 2029

•Novo Nordisk initiated the Phase 3 CLEOPATTRA trial evaluating coramitug in ATTR amyloidosis with cardiomyopathy in 4Q 2025; primary completion expected in 2029

•Bristol Myers Squibb fully enrolled the Phase 2 TargetTau-1 trial evaluating BMS-986446 in early Alzheimer’s disease with primary completion expected in 1H 2027, completed a Phase 1 trial evaluating a subcutaneous formulation of BMS-986446 and obtained Fast Track designation from the U.S.

Original on sec.gov

Prompts

Prothena Corporation plc (ticker PRTA), listed in United States.

Company History

Date	Change	Detail
Aug 6, 2020	Renamed	PROTHENA CORP PLC → PROTHENA CORP PUBLIC LTD CO
Oct 29, 2012	Renamed	Neotope Corp Ltd → PROTHENA CORP PLC

Prothena Corporation plc

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