SCHEDULE 13G

CUSIP No.

G72800108

Names of Reporting Persons

ADAR1 Capital Management, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

TEXAS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,469,098.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,469,098.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,469,098.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

2.7 %

Type of Reporting Person (See Instructions)

IA, OO

Comment for Type of Reporting Person: Includes (i) 1,189,587 Ordinary Shares, par value $0.01 per share ("Ordinary Shares") held by ADAR1 Partners, LP, (ii) 195,568 Ordinary Shares held by Spearhead Insurance Solutions IDF, LLC and (iii) 83,943 Ordinary Shares held by other separately managed accounts as of September 30, 2025. As the investment manager of ADAR1 Partners, LP and as the sub-advisor of Spearhead Insurance Solutions IDF, LLC and the separately managed accounts referenced above, ADAR1 Capital Management, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC and the separately managed accounts. Based on 53,829,982 Ordinary Shares of Prothena Corporation Public Limited Company (the "Issuer") outstanding as of September 30, 2025 reported in the Issuer's 10-Q for the quarterly period ended September 30, 2025, filed with the SEC on November 6, 2025.

SCHEDULE 13G

CUSIP No.

G72800108

Names of Reporting Persons

ADAR1 Capital Management GP, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

TEXAS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,189,587.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,189,587.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,189,587.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

2.2 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: Includes 1,189,587 ordinary shares, $0.01 per share ("Ordinary Shares") held by ADAR1 Partners, LP as of September 30, 2025. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP. Based on 53,829,982 Ordinary Shares of Prothena Corporation Public Limited Company (the "Issuer") outstanding as of September 30, 2025 reported in the Issuer's 10-Q for the quarterly period ended September 30, 2025, filed with the SEC on November 6, 2025.

SCHEDULE 13G

CUSIP No.

G72800108

Names of Reporting Persons

Daniel Schneeberger

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

SWITZERLAND

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,469,098.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,469,098.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,469,098.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

2.7 %

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Includes (i) 1,189,587 ordinary shares, par value $0.01 per share ("Ordinary Shares") held by ADAR1 Partners, LP, (ii) 195,568 Ordinary Shares held by Spearhead Insurance Solutions IDF, LLC and (iii) 83,943 Ordinary Shares held by other separately managed accounts as of September 30, 2025. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Mr. Schneeberger may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC and the separately managed accounts referenced above. Based on 53,829,982 Ordinary Shares of Prothena Corporation Public Limited Company (the "Issuer") outstanding as of September 30, 2025 reported in the Issuer's 10-Q for the quarterly period ended September 30, 2025, filed with the SEC on November 6, 2025.

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

Prothena Corporation Public Limited Company

(b)

Address of issuer's principal executive offices:

77 Sir John Rogerson's Quay, Block C Grand Canal Docklands Dublin 2, L2, D02 VK60

Item 2.

(a)

Name of person filing:

This Schedule is being filed on behalf of each of the following persons (each, a "Reporting Person" and collectively, the "Reporting Persons"): (i) ADAR1 Capital Management, LLC ("ADAR1 Capital Management"); (ii) ADAR1 Capital Management GP, LLC ("ADAR1 General Partner"); and (iii) Daniel Schneeberger ("Mr. Schneeberger").

(b)

Address or principal business office or, if none, residence:

The address of the principal business office of each of the Reporting Persons is 3503 Wild Cherry Drive, Building 9, Austin, Texas 78738.

(c)

Citizenship:

(i) ADAR1 Capital Management is a Texas limited liability company; (ii) ADAR1 General Partner is a Texas limited liability company; and (iii) Mr. Schneeberger is a citizen of Switzerland.

(d)

Title of class of securities:

Ordinary Shares, par value $0.01 per share

(e)

CUSIP No.:

G72800108

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: