# EDGAR Filing Document

**Accession Number:** 0001559053
**File Stem:** 0001045463-26-000003
**Filing Date:** 2026-5
**Character Count:** 11237
**Document Hash:** d21f7288b6a57a8836210733ff03aeb5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001045463-26-000003.hdr.sgml**: 20260514

**ACCESSION NUMBER**: 0001045463-26-000003

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260507

**FILED AS OF DATE**: 20260514

**DATE AS OF CHANGE**: 20260514

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** SCULLY WILLIAM P
- **CENTRAL INDEX KEY:** 0001045463

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-35676
- **FILM NUMBER:** 26981102

**MAIL ADDRESS:**
- **STREET 1:** C/O MCGRATH DOYLE & PHAIR
- **STREET 2:** 150 BROADWAY
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10038
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** PROTHENA CORP PUBLIC LTD CO
- **CENTRAL INDEX KEY:** 0001559053
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** L2
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 77 SIR JOHN ROGERSON'S QUAY, BLOCK C
- **STREET 2:** GRAND CANAL DOCKLANDS
- **CITY:** DUBLIN 2
- **STATE:** L2
- **ZIP:** D02 VK60
- **BUSINESS PHONE:** 011-353-1-236-2500

**MAIL ADDRESS:**
- **STREET 1:** 77 SIR JOHN ROGERSON'S QUAY, BLOCK C
- **STREET 2:** GRAND CANAL DOCKLANDS
- **CITY:** DUBLIN 2
- **STATE:** L2
- **ZIP:** D02 VK60

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Prothena Corp plc
- **DATE OF NAME CHANGE:** 20121102

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Neotope Corp Ltd
- **DATE OF NAME CHANGE:** 20120926

## Ex-24

Power-of-Attorney_Exhibit 24 
```
<pre>
                                                             Exhibit 24
POWER OF ATTORNEY
The undersigned, William P. Scully, hereby makes, constitutes and appoints each
of Reid E. Buchanan, Diana L. Hayes, and Todd W. Fennell, or any of them acting
singly, and with full power of substitution, re-substitution and delegation,
the undersigned's true and lawful attorney-in-fact (each of such persons and
their substitutes and delegees being referred to herein as the "Attorney-in-
Fact"), with full power to act for the undersigned and in the undersigned's
name, place and stead, in the undersigned's capacity as a stockholder of
Prothena Corp Public Ltd Co (the "Company"), to:
    1. Take such actions as may be necessary or appropriate to enable the
undersigned to submit and file forms, schedules and other documents with
the U.S. Securities and Exchange Commission ("SEC") utilizing the SEC's
Electronic Data Gathering and Retrieval ("EDGAR") system, which actions may
include (a) enrolling the undersigned in EDGAR Next and (b) preparing, executing
and submitting to the SEC a Form ID, amendments thereto (without limiting the
generality of the foregoing, Attorney-in-Fact shall have the specific legal
authority to bind the undersigned for purposes of Form ID), and such other
documents and information as may be necessary or appropriate to obtain codes and
passwords enabling the undersigned to make filings and submissions utilizing
the EDGAR system;
    2. Prepare and execute any and all forms, schedules and other documents
(including any amendments thereto) the undersigned is required to file with the
SEC, or which the Attorney-in-Fact considers it advisable for the undersigned
to file with the SEC, under Section 13 or Section 16 of the Securities Exchange
Act of 1934 ("Exchange Act") or any rule or regulation thereunder, or under
Rule 144 ("Rule 144") under the Securities Act of 1933 ("Securities Act"),
including Forms 3, 4 and 5, Schedules 13D and 13G, and Forms 144 (all such
forms, schedules and other documents being referred to herein as "SEC Filings");
    3. Submit and file SEC Filings with the SEC utilizing the EDGAR system
or cause them to be submitted and filed by a person appointed under Section
5 below;
    4. File, submit or otherwise deliver SEC Filings to any securities exchange
on which the Company's securities may be listed or traded;
    5. Act as an account administrator for the undersigned's EDGAR account,
including: (i) appoint, remove and replace account administrators, account
users, technical administrators and delegated entities; (ii) maintain the
security of the undersigned's EDGAR account, including modification of
access codes; (iii) maintain, modify and certify the accuracy of information
on the undersigned's EDGAR account dashboard; (iv) act as the EDGAR point of
contact with respect to the undersigned's EDGAR account; and (v) any other
actions contemplated by Rule 10 of Regulation S-T with respect to account
administrators.
    6. Obtain, as the undersigned's representative and on the undersigned's
behalf, information regarding transactions in the Company's equity securities
from any third party, including the Company and any brokers, dealers, employee
benefit plan administrators and trustees, and the undersigned hereby authorizes
any such third party to release any such information to the Attorney-in-Fact.
	The undersigned acknowledges and agrees that:
a) This Power of Attorney authorizes, but does not require, the Attorney-in-
Fact to act in his or her discretion on information provided to such Attorney
-in-Fact without independent verification of such information;
b)	Any documents prepared or executed by the Attorney-in-Fact on behalf
of the undersigned pursuant to this Power of Attorney will be in such form
and will contain such information as the Attorney-in-Fact, in his or her
discretion, deems necessary or desirable;
c)	Neither the Company nor the Attorney-in-Fact assumes any liability
for the undersigned's responsibility to comply with the requirements of
Section 13 or Section 16 of the Exchange Act or Rule 144 under the
Securities Act, any liability of the undersigned for any failure to comply
with such requirements, or any liability of the undersigned for disgorgement
of profits under Section 16(b) of the Exchange Act; and
d)	This Power of Attorney does not relieve the undersigned from
responsibility for compliance with the undersigned's obligations under
Section 13 or Section 16 of the Exchange Act, including, without limitation,
the reporting requirements under Section 13 or Section 16 of the Exchange Act.
	The undersigned hereby grants to the Attorney-in-Fact full power and
authority to do and perform each and every act and thing requisite, necessary
or advisable to be done in connection with the foregoing, as fully, to all
intents and purposes, as the undersigned might or could do in person, hereby
ratifying and confirming all that the Attorney-in-Fact, or his or her
substitute or substitutes, shall lawfully do or cause to be done by authority
of this Power of Attorney.
	This Power of Attorney shall remain in full force and effect until it
is revoked by the undersigned in a signed writing delivered to the Attorney-
in-Fact. This Power of Attorney revokes all previous powers of attorney with
respect to the subject matter of this Power of Attorney.
	IN WITNESS WHEREOF, the undersigned has executed this Power of
Attorney as of September 4, 2025.
	WITNESSES:

Sign:/s/ Lauren Taiaga		/s/ William P. Scully
Print: Lauren Taiaga		William P. Scully

Sign: /s/ Jennifer Lea Cear
Print: Jennifer Lea Coar

NOTARIZATION

STATE OF FLORIDA
COUNTY OF INDIAN RIVER
       The foregoing Power of Attorney was acknowledged before me by means of
[check one]: [x] physical presence or [__] online notarization, this 4th day
of September, 2025, by WILLIAM P. SCULLY, who either [check one]: [x] is
personally known to me, [__] has produced a Florida driver's license as
identification, [__] has produced a ______________ driver's license as
identification, or [__] has produced _____________________________ as
identification.

NOTARY PUBLIC:
Sign:/s/ April S. Chiarella
(NOTARY SEAL)	Print: April S. Chiarella
State of Florida at Large (Seal)
My commission expires: 8-19-28

</pre>
```

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>SCULLY WILLIAM P<br><sub>(Last) (First) (Middle)</sub><br>771 MANATEE COVE<br><sub>(Street)</sub><br>VERO BEACH, FL 32963<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>PROTHENA CORP PUBLIC LTD CO [ PRTA ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-05-07 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [X] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Ordinary Shares, par value $0.01 per share | 736000 | D |  |
| Ordinary Shares, par value $0.01 per share | 80000 | I | By Manatee Equity Fund LLC<sup>(1)</sup> |
| Ordinary Shares, par value $0.01 per share | 52000 | I | By Spouse |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein.

**Remarks:**
Exhibit List: Exhibit 24 - Power of Attorney

**Signature:** Reid E. Buchanan by POA from William P. Scully  
**Date:** 2026-05-14

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**