PROTHENA CORP PUBLIC LTD CO

Listed Company

PRTACIK 0001559053NasdaqAcceleratedPharmaceutical PreparationsL2FY ends Dec 31

Period

FY 2025

Revenue

$9.68M

Net Income

$-244.09M

Total Assets

$326.80M

Equity

$280.47M

Shares Out

52.35M

Op. Cash Flow

$-163.58M

PRTA$8.65+33.28% · past yearDBEQ Basic

Daily closing prices

Business

Prothena Corporation plc is a clinical-stage biotechnology company developing therapeutic antibodies targeting protein dysregulation in neurodegenerative and rare amyloid diseases. The company advances programs for Parkinson's disease, ATTR amyloidosis, Alzheimer's disease, and ALS through wholly-owned and partnered development. Key partnered assets include prasinezumab with Roche and coramitug with Novo Nordisk, while the proprietary CYTOPE® platform targets intracellular protein misfolding. Prothena operates through licensing partnerships with large pharmaceutical companies.

Summary from 10-K filed 2026-02-27

Financials

Consolidated Statement of Income

Year Ended · In millions, except per-share amounts

Concept	FY 2025 2025-12-31	FY 2024 2024-12-31	FY 2023 2023-12-31	FY 2022 2022-12-31	FY 2021 2021-12-31
Revenues	10	135	91	54	201
Research and development	135	223	221	136	82
General and administrative	59	67	62	50	46
Restructuring costs	30	0	0	—	0
Total operating expenses	224	290	282	185	129
Loss from operations	−215	−155	−191	−132	72
Interest income	14	26	31	6	42,000
Other expense, net	−328,000	−185,000	−458,000	−397,000	−96,000
Total other income, net	14	26	31	6	−54,000
Loss before provision for income taxes	−201	−129	−160	−126	72
Provision for (benefit from) income taxes	43	−7	−13	−9	5
Net loss	−244	−122	−147	−117	67
Basic net loss per ordinary share (in USD per share)	−4.53	−2.27	−2.76	−2.47	1.51
Diluted net loss per ordinary share (in USD per share)	−4.53	−2.27	−2.76	−2.47	1.38
Shares used to compute basic net loss per share (in shares)	54	54	53	47	44
Shares used to compute diluted net loss per share (in shares)	54	54	53	47	48

Consolidated Balance Sheet

As of · In millions, except per-share amounts

Concept	FY 2025 2025-12-31	FY 2024 2024-12-31	FY 2023 2023-12-31	FY 2022 2022-12-31	FY 2021 2021-12-31
Cash and cash equivalents	308	471	619	710	579
Prepaid expenses and other current assets	8	14	14	9	6
Total current assets	315	485	639	719	585
Property and equipment, net	2	3	4	2	2
Operating lease right-of-use assets	8	11	12	6	12
Deferred tax assets	0	43	34	18	7
Restricted cash, non-current	860,000	860,000	860,000	2	1
Other non-current assets	482,000	4	6	11	2
Total non-current assets	12	62	57	39	25
Total assets	327	547	696	758	609
Accounts payable	6	8	25	9	4
Accrued research and development	4	13	15	11	6
Deferred revenue, current	3	9	0	11	8
Restructuring liability	13	0	—	—	—
Lease liability, current	3	3	1	6	6
Other current liabilities	12	16	16	12	10
Total current liabilities	41	49	57	50	33
Deferred revenue, non-current	0	3	67	85	103
Lease liability, non-current	5	8	11	0	6
Total non-current liabilities	5	12	78	86	110
Total liabilities	46	60	135	136	143
Commitments and contingencies (Note 6)	—	—	—	—	—
Euro deferred shares, 22 nominal value: Authorized shares 10,000 at December 31, 2025 and 2024 Issued and outstanding shares none at December 31, 2025 and 2024	0	0	0	0	0
Ordinary shares, $0.01 par value: Authorized shares 100,000,000 at December 31, 2025 and 2024 Issued and outstanding shares 53,832,982 and 53,826,982 at December 31, 2025 and 2024, respectively	538,000	538,000	537,000	521,000	466,000
Additional paid-in capital	1,626	1,589	1,541	1,455	1,182
Accumulated deficit	−1,300	−1,102	−980	−833	−716
Total shareholders equity	280	487	561	622	466
Total liabilities and shareholders equity	327	547	696	758	609

Consolidated Statement of Cash Flows

Year Ended · In millions, except per-share amounts

Concept	FY 2025 2025-12-31	FY 2024 2024-12-31	FY 2023 2023-12-31	FY 2022 2022-12-31	FY 2021 2021-12-31
Depreciation	895,000	893,000	928,000	744,000	1
Share-based compensation	38	46	41	31	25
Deferred income taxes	43	−9	−16	−11	5
Reduction in the carrying amount of right-of-use assets	3	3	7	6	6
Loss on disposal of fixed assets	104,000	0	15,000	1,000	0
Accounts receivable	0	5	−5	0	15,000
Prepaid expenses and other assets	11	3	−3	−11	−5
Deferred revenue	−10	−55	−29	−14	348,000
Restructuring liability	13	0	0	—	0
Accounts payable, accruals and other liabilities	−16	−18	23	12	−492,000
Operating lease liabilities	−3	−2	−6	−6	−6
Net cash used in operating activities	−164	−150	−134	−109	93
Purchases of property and equipment	−138,000	−298,000	−3	−464,000	−575,000
Proceeds from disposal of fixed assets	0	0	37,000	0	0
Net cash used in investing activities	−138,000	−298,000	−3	−464,000	−575,000
Proceeds from issuance of ordinary shares upon exercise of stock options	0	2	22	18	16
Net cash provided by (used in) financing activities	−139,000	2	45	241	190
Net decrease in cash, cash equivalents and restricted cash	−164	−149	−92	132	282
U.S. Federal	900,000	3	1	—	—
U.S. State and Local	31,000	62,000	87,000	—	—
Cash paid for income taxes, net	931,000	3	2	3	580,000
Acquisition of property and equipment included in accounts payable and accrued liabilities	0	75,000	237,000	0	0
Right-of-use assets obtained in exchange for lease obligations	224,000	217,000	4	151,000	0
Reclassification of prepaid lease payments to right-of-use assets upon lease commencement	0	0	8	0	0

Filings

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Frequently asked questions

What is PROTHENA CORP PUBLIC LTD CO's CIK number?

PROTHENA CORP PUBLIC LTD CO's SEC CIK number is 0001559053 (1559053). The CIK (Central Index Key) is the permanent identifier the SEC assigns to every EDGAR filer — unlike a ticker symbol, it never changes.

Where can I find PROTHENA CORP PUBLIC LTD CO's SEC filings?

All of PROTHENA CORP PUBLIC LTD CO's EDGAR filings — 10-K annual reports, 10-Q quarterly reports, 8-K material events, and insider transactions — are listed on this page, sourced live from SEC EDGAR.

When did PROTHENA CORP PUBLIC LTD CO last report earnings?

PROTHENA CORP PUBLIC LTD CO (PRTA) most recently filed an earnings 8-K with the SEC on May 7, 2026, furnishing its results under Item 2.02 (Results of Operations and Financial Condition). The earnings press release is attached to that filing (accession 0001559053-26-000016). This is PROTHENA CORP PUBLIC LTD CO's most recent earnings filing of record — not a forecast of its next earnings date.

What is PROTHENA CORP PUBLIC LTD CO's most recent earnings 8-K?

PROTHENA CORP PUBLIC LTD CO's latest earnings 8-K (Item 2.02) was filed May 7, 2026 under accession 0001559053-26-000016. It carries the quarterly or annual earnings press release — the earliest official, SEC-filed version of the results.

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