# EDGAR Filing Document

**Accession Number:** 0001045463
**File Stem:** 0001045463-26-000002
**Filing Date:** 2026-5
**Character Count:** 15539
**Document Hash:** 008fec75856bd7a413a1c12fd31609fc
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001045463-26-000002.hdr.sgml**: 20260511

**ACCESSION NUMBER**: 0001045463-26-000002

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20260511

**DATE AS OF CHANGE**: 20260511

**SUBJECT COMPANY**: 

**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

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-87112
- **FILM NUMBER:** 26962673

**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
**FILED BY**: 

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

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

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

## Ex-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

```

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 6)**

**Issuer:** PROTHENA CORP PUBLIC LTD CO

**Title of Class of Securities:** Ordinary Shares, $0.01 par value

**CUSIP Number:** —

**Date of Event Which Requires Filing of this Statement:** 05/07/2026

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>SCULLY WILLIAM P | Names of Reporting Persons<br>SCULLY WILLIAM P |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>FL | Citizenship or Place of Organization<br>FL |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>793000.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>4585846.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>793000.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>4585846.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>5378846.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>5378846.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>10.3% | Percent of Class Represented by Amount in Row (9)<br>10.3% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** *See Item 4

---

**Item 1(a). Name of Issuer:**
PROTHENA CORP PUBLIC LTD CO

**Item 1(b). Address of Issuer's Principal Executive Offices:**
77 SIR JOHN ROGERSON'S QUAY, BLOCK C, GRAND CANAL DOCKLANDS, DUBLIN 2, IRELAND, D02 VK60.

**Item 2(a). Name of Person Filing:**
William P Scully

**Item 2(b). Address of Principal Business Office:**
771 Manatee Cove, Vero Beach, Florida 32963

**Item 2(c). Citizenship:**
Florida

**Item 2(d). Title of Class of Securities:**
Ordinary Shares, $0.01 par value

**Item 2(e). CUSIP Number:**
—

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

The Reporting Person may be deemed to be the beneficial owner of 5,378,846 Ordinary Shares.  This amount consists of (i) 80,000 Ordinary Shares owned by Manatee Equity Fund LLC, of which the Reporting Person is the sole manager with sole voting and dispositive power, (ii) 713,000 Ordinary Shares owned by the Reporting Persons IRA, over which he has sole voting and dispositive power, (iii) 42,000 Ordinary Shares owned by the Reporting Persons spouses IRA, over which he may be deemed to have shared voting and dispositive power, (iv) 10,000 Ordinary Shares owned by the Reporting Persons spouse, over which he may be deemed to have shared voting and dispositive power (v) 23,000 Ordinary Shares owned by an IRA subject to an investment management agreement over which the Reporting Person may be deemed to have shared voting and dispositive power by reason of his right to terminate such agreement, (vii) 4,470,846 Ordinary Shares owned in the aggregate by various grantor retained annuity trusts, which have an independent trustee, but over which the Reporting Person may be deemed to have shared voting and dispositive power by reason of his retained right to substitute assets in such trusts, and (viii) 40,000 Ordinary Shares owned by another trust, which has an independent trustee, but over which the Reporting Person may be deemed to have shared voting and dispositive power by reason of his retained right to substitute assets in such trust

**(b) Percent of class:**

According to the Issuers most recent Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, as filed with the Securities and Exchange Commission on May 7, 2026, the number of shares outstanding as of April 30, 2026 was 52,353,237.  The Ordinary Shares which the Reporting Person may be deemed to beneficially own constitute approximately 10.27% of such total number of shares

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

793,000

**(ii) Shared power to vote or to direct the vote:**

4,585,846

**(iii) Sole power to dispose or to direct the disposition of:**

793,000

**(iv) Shared power to dispose or to direct the disposition of:**

4,585,846

**Item 5. Ownership of Five Percent or Less of a Class.**

[x] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**SCULLY WILLIAM P**

**Date:** 05/11/2026

**By:** /s/ Diana L. Hayes

**Name & Title:** Attorney-in-fact