As of Nov 2, 2026: Michael John Isaacs (General Counsel & Company Sec., PRTA) reported 1 sale for $71K in the last 12 months (Form 4). PRTA's Quality Score is 0. Scores as of 7:55 PM ET, 15 minutes behind.

MI

Michael John Isaacs

General Counsel & Company Sec. of Prothena Corporation

1 stock trade in the last 12 months, shares they bought or sold themselves (not grants or options).

Bought: $0, 12 monthsSold: $71K, 12 monthsLast filed: Jul 30, a planned sale

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From SEC Form 4s · Insiders have 2 business days to file a trade

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Every trade Michael John Isaacs reported

One sale was under a trading plan set up in advance.

Newest first, as filed

Stock	Trade	Amount	Trade	Shares	Traded Filed
PRTAProthena	Sell(10b5-1 plan)	$71Kat $8.47	Sell(10b5-1 plan)$71Kat $8.47	8,386 at $8.47	Jul 29filed Jul 30SEC filing

Their filings on the SEC's siteEvery Form 4 they filed, as filed, on EDGAR.

Their other filing ›

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Michael John Isaacs' companies

Where they file, with the stock's Quality Score

Company	Title, as filed	Trades	Quality Score
PRTAProthenaGeneral Counsel & Company Sec.	General Counsel & Company Sec.filed Jul 30	1	0

Alerts for Michael John Isaacs

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Use this page

Kept by Andrew Gomes, Breakaway's founder, from the SEC's Form 4 filings. Updated Jul 30, 2026.

Free to reuse with a link to this page.

How to cite

Breakaway, Michael John Isaacs: General Counsel & Company Sec. at PRTA, Jul 30, 2026, getbreakaway.com/insiders/michael-john-isaacs

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Others who file at Prothena Corporation

• Gene G. KinneyPresident and CEO
• Tran NguyenChief Strategy Officer and CFO
• Anne Evans KingstonChief Strategy Officer
• Brandon S. SmithChief Operating Officer
• Chad J. SwansonChief Development Officer
• Karin L. WalkerChief Accounting Officer
• Wagner M. ZagoChief Scientific Officer

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