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PROTHENA CORP PUBLIC LTD CO insider William P. Scully filed an initial ownership report as a ten percent owner of PRTA. He reports 736,000 ordinary shares held directly, plus 80,000 shares held indirectly through Manatee Equity Fund LLC and 52,000 shares held indirectly by his spouse. A footnote states he disclaims beneficial ownership of these securities except to the extent of his pecuniary interest.
Prothena Corp Public Ltd: William P. Scully filed an amended Schedule 13G/A reporting beneficial ownership of 5,378,846 Ordinary Shares, representing approximately 10.27% of the company's 52,353,237 shares outstanding as of April 30, 2026. The filing breaks ownership into positions with 793,000 shares of sole voting/dispositive power and 4,585,846 shares of shared voting/dispositive power.
Prothena Corporation plc reported a profitable quarter for the period ended March 31, 2026. Total revenue rose to $51.1 million, driven mainly by a $50.0 million development milestone payment from Novo Nordisk related to coramitug, alongside $1.0 million of collaboration revenue from Bristol Myers Squibb.
The company generated net income of $32.7 million, or $0.60 per diluted share, compared with a net loss of $60.2 million a year earlier. Research and development expense fell to $12.6 million from $50.8 million, reflecting lower spend after discontinuing birtamimab and the impact of a $4.2 million net reduction in restructuring costs.
Cash and cash equivalents were $329.5 million, and management believes this balance will fund operations for at least 12 months. Prothena repurchased 788,990 ordinary shares for about $7.3 million and ended the quarter with 53.1 million shares outstanding and shareholders’ equity of $312.6 million, while continuing to advance late-stage programs with Roche, Novo Nordisk and Bristol Myers Squibb.
Prothena Corporation plc reported strong first quarter 2026 results, with total revenue of $51.1 million and net income of $32.7 million, compared with a net loss of $60.2 million a year earlier. Results were driven mainly by a $50 million milestone payment from Novo Nordisk and lower research and development and general and administrative expenses, plus a $4.2 million restructuring credit.
Quarter-end cash, cash equivalents and restricted cash were $330.3 million and the company had no debt. Prothena cut its projected 2026 net cash used in operating and investing activities to $18–$23 million and now expects to end 2026 with about $273 million in cash (midpoint). It also authorized a 2026 share repurchase program for up to $100 million, repurchasing 788,990 shares for $7.3 million through March 31, 2026.
Operationally, Novo Nordisk obtained U.S. FDA Fast Track designation for coramitug and paid the $50 million milestone, Roche presented multiple positive prasinezumab data updates, Prothena completed a Phase 1 study for PRX019 with potential for a $55 million milestone from Bristol Myers Squibb, and preclinical CYTOPE and PRX012-TfR programs continued to advance.
PROTHENA CORP PUBLIC LTD CO granted Chief Strategy Officer Anne Evans Kingston a stock option covering 100,000 Ordinary Shares. The option has a grant exercise price of $10.50 per share and expires on April 10, 2036.
The award vests over four years: 25% of the shares vest and become exercisable on April 10, 2027, with the remaining shares vesting in equal monthly installments (1/48th of the total) on each monthly anniversary thereafter, contingent on her continued employment.
Prothena Corp Public Ltd Co’s Chief Strategy Officer Anne Evans Kingston filed an initial ownership report showing her equity position in the company. She directly holds 66,942 Ordinary Shares and a series of employee stock options over additional Ordinary Shares.
The options cover 5,000 shares at $53.81 per share expiring on May 1, 2033, 3,000 shares at $30.30 per share expiring on February 27, 2034, and 14,080 shares at $14.95 per share expiring on March 5, 2035. Footnotes explain that each grant vests 25% on an initial date, then in equal monthly installments over four years, conditioned on her continued employment with Prothena on each vesting date.
Prothena Corporation plc has called its 2026 annual general meeting for May 14, 2026 in Dublin. Shareholders will vote on re‑electing directors Shane M. Cooke and Dennis J. Selkoe, ratifying KPMG LLP as auditor, and approving 2025 executive pay in an advisory “say‑on‑pay” vote.
Only holders of the company’s 53,832,982 ordinary shares as of March 2, 2026 may vote, one vote per share, with a simple majority of votes cast required for each proposal. The proxy details extensive governance practices, director independence, and committee structures.
The filing also reviews 2025 performance: termination of birtamimab after a failed Phase 3 trial and a workforce reduction of about 63%, alongside progress in partnered late‑stage programs with Roche, Novo Nordisk, and Bristol Myers Squibb. Prothena reports cash used in operating and investing activities of $163.7M, better than guidance, and year‑end liquidity of $308.4M, above a $298.0M target.
Zago Wagner M. reported acquisition or exercise transactions in this Form 4 filing.
PROTHENA CORP PUBLIC LTD CO reported that Chief Scientific Officer Zago Wagner M. was granted a stock option covering 190,000 shares of the company’s stock. The option was reported at a grant price of $0.00 per share and is held as direct ownership.
According to the vesting terms, 25% of the total shares under the option will vest and become exercisable on March 3, 2027. The remaining shares will vest in 1/48th increments in equal monthly installments on each monthly anniversary after that date, conditioned on Wagner’s continued employment with the company on each vesting date.
PROTHENA CORP PUBLIC LTD CO reported that Chief Accounting Officer Karin L. Walker acquired a stock option covering 150,000 shares of the company’s stock. This option was reported as a grant or award acquisition in a Form 4 insider filing.
According to the vesting terms, 25% of the 150,000 shares subject to the option will vest and become exercisable on March 3, 2027. The remaining portion will vest in 1/48th increments in equal monthly installments on each monthly anniversary after that date, conditioned on Ms. Walker’s continued employment with the company on each vesting date.