Welcome to our dedicated page for Prothena SEC filings (Ticker: PRTA), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
The Prothena Corporation plc (NASDAQ: PRTA) SEC filings page on Stock Titan brings together the company’s regulatory disclosures from the U.S. Securities and Exchange Commission, alongside AI-powered summaries designed to make these documents easier to understand. Prothena is an Irish public limited company whose ordinary shares trade on The Nasdaq Global Select Market, and it files reports such as Forms 8-K and proxy statements in connection with material events and shareholder meetings.
Recent 8-K filings referenced by the company include disclosures about quarterly financial results, workforce reductions following the discontinuation of the birtamimab program, collaboration developments such as Novo Nordisk advancing coramitug (formerly PRX004) for ATTR amyloidosis with cardiomyopathy, and updates on the PRX012 Phase 1 ASCENT clinical program. Other 8-Ks describe governance and compensation matters, including employment agreements for senior officers and the planned resignation of a Board member, as well as the outcome of an Extraordinary General Meeting where shareholders approved a reduction of capital to create distributable reserves.
Prothena’s definitive proxy statement for the Extraordinary General Meeting explains the rationale for the capital reduction and outlines voting procedures for shareholders of the Irish public limited company. These filings, together with the company’s periodic reports referenced in its press releases, form the official record of Prothena’s financial condition, capital structure decisions, and key operational events.
On Stock Titan, users can access Prothena’s SEC filings as they are made available through EDGAR and use AI-generated highlights to quickly identify the main points in lengthy documents. For PRTA, this can include understanding how collaboration revenue from partners like Bristol Myers Squibb is reported, how restructuring charges are described, and how shareholder approvals are documented in connection with potential share redemption programs and other capital management actions.
Prothena Corporation plc amends its shelf registration to permit the offer and issuance of up to
The prospectus describes the general terms for future takedowns under the shelf, the requirement that each offering be accompanied by a prospectus supplement with specific amounts, prices and terms, and that offerings may be conducted through underwriters, dealers, agents or directly to purchasers.
Prothena Corporation plc reported significantly weaker 2025 financial results while highlighting progress across its partnered neurology pipeline. For 2025, the company posted a net loss of $244.1 million, nearly double the prior year’s $122.3 million, as revenue fell to $9.7 million from $135.2 million driven by lower collaboration payments.
Research and development expenses declined to $134.9 million and general and administrative expenses to $59.4 million, reflecting lower clinical, personnel, manufacturing, and consulting costs, though results included $30.1 million of restructuring charges and a $43.2 million non-cash tax expense. Prothena ended 2025 with $308.4 million in cash, cash equivalents and restricted cash and no debt, and had about 53.8 million ordinary shares outstanding as of February 12, 2026.
For 2026, Prothena expects net cash used in operating and investing activities of $50–$55 million and to finish the year with roughly $255 million in cash at the midpoint, excluding up to $105 million of potential clinical milestone receipts from partners. The company also secured shareholder and court approval to create distributable reserves, allowing its board to consider a share redemption program in 2026 at its discretion, and noted multiple late-stage trials with Roche, Novo Nordisk, and Bristol Myers Squibb targeting Parkinson’s, ATTR amyloidosis, and Alzheimer’s disease.
Rubric Capital Management LP and David Rosen disclosed beneficial ownership of Prothena Corporation plc’s ordinary shares. They report holding 3,677,331 ordinary shares, representing 6.83% of the outstanding class.
The percentage is calculated based on 53,829,982 ordinary shares outstanding as of October 31, 2025, as reported by Prothena. Rubric Capital Master Fund LP has the right to receive dividends or sale proceeds on more than 5% of the shares. The investors state that the shares are held in the ordinary course of business and not for the purpose of changing or influencing control of Prothena.
Prothena Corporation plc disclosed that director Paula Cobb has decided to resign from its Board of Directors, effective December 31, 2025. Until that date, she will continue serving on the Board as well as on the Compensation Committee and the Audit Committee.
The company stated that Ms. Cobb’s decision to step down was not because of any disagreement with Prothena on matters related to its operations, policies, or practices, suggesting this is a routine governance change rather than a dispute-driven departure.
Prothena Corporation plc reported the results of an extraordinary general meeting of shareholders held on
The proposal was approved with 37,779,052 votes in favor, 46,738 against, and 45,906 abstentions. Creating distributable reserves is an Irish corporate law mechanism that can give a company more flexibility to make future distributions, such as dividends or other returns of value, if its board later chooses to do so and other legal requirements are met. This update reflects a change in Prothena’s capital structure authorization rather than an immediate financial transaction.
Prothena (PRTA) reported Q3 2025 results showing modest collaboration revenue and lower operating spend amid an ongoing restructuring. Total revenue was $2.4 million for the quarter and $9.7 million year-to-date. Research and development expense declined to $28.9 million in Q3, with program spend led by PRX012 ($14.7 million), followed by birtamimab ($7.1 million) and PRX019 ($2.2 million). General and administrative expense was $13.2 million in Q3; restructuring costs totaled $33.1 million year-to-date.
The company recorded a Q3 net loss of $36.5 million and a year-to-date net loss of $222.5 million. Cash and cash equivalents were $330.8 million as of September 30, 2025, compared with $471.4 million at year-end 2024, reflecting $140.3 million used in operating activities year-to-date. Shareholders’ equity was $295.0 million, with total assets of $352.6 million.
Prothena’s collaboration with BMS continues to contribute deferred revenue tied to the PRX019 Phase 1 clinical trial obligation, with $2.4 million recognized in Q3 and $2.7 million remaining as of quarter end. Ordinary shares outstanding were 53,829,982 as of October 31, 2025.
Prothena Corporation plc furnished a press release announcing its financial results for the third quarter ended September 30, 2025. The press release is attached as Exhibit 99.1 to a current report on Form 8-K dated November 6, 2025. The company states that the information provided under Item 2.02 and Exhibit 99.1 is furnished and not deemed “filed” under Section 18 of the Exchange Act.
Prothena Corporation plc is asking shareholders to approve a reduction of capital to create distributable reserves at an Extraordinary General Meeting to be held on
The Proxy Statement will be made available primarily via the internet on or about
Prothena Corporation plc is soliciting proxies for an Extraordinary General Meeting on November 19, 2025 in Dublin to approve a proposed reduction of capital to create distributable reserves. The Board unanimously recommends a FOR vote on Proposal No. 1. Shareholders of record as of September 24, 2025 may vote; there were 53,829,928 ordinary shares outstanding on the Record Date. The company is primarily delivering proxy materials via the internet and will mail a Notice of Internet Availability; paper copies can be requested. Voting options include in-person, mail, internet, and telephone with revocation permitted until 11:59 p.m. ET on November 18, 2025. Procedures for director nominations for 2026 are specified with notice windows and universal proxy compliance dates.
Prothena Corporation plc filed a report stating that it issued a press release on August 27, 2025. The release provides an update on its PRX012 investigational drug and shares results from the Phase 1 ASCENT clinical program. The press release is included as Exhibit 99.1 and is incorporated by reference, meaning the detailed clinical information is contained in that exhibit rather than in this summary document.