RA Capital discloses 7.1% GH Research PLC (GHRS) stake in Schedule 13G/A

Rhea-AI Filing Summary

RA Capital Management, L.P., together with affiliated funds and managers Peter Kolchinsky and Rajeev Shah, reports beneficial ownership of 4,897,182 ordinary shares of GH Research PLC, representing 7.1% of the outstanding class, based on 68,642,287 ordinary shares outstanding as of the issuer’s Form 6-K filed August 6, 2026.

The holdings include 4,768,564 shares held by RA Capital Healthcare Fund, L.P. and 128,618 shares held by RA Capital Nexus Fund II, L.P., for which RA Capital has voting and dispositive power under advisory arrangements. The reporting persons and funds include detailed disclaimers of beneficial ownership and group status for purposes other than Section 13(d).

Key Figures

Shares beneficially owned: 4,897,182 ordinary shares Percent of class: 7.1% Shares held by Healthcare Fund: 4,768,564 ordinary shares +2 more

5 metrics

Shares beneficially owned 4,897,182 ordinary shares Aggregate ordinary shares of GH Research PLC reported by RA Capital and affiliates

Percent of class 7.1% Portion of GH Research PLC ordinary shares beneficially owned by reporting persons

Shares held by Healthcare Fund 4,768,564 ordinary shares Ordinary shares directly held by RA Capital Healthcare Fund, L.P.

Shares held by Nexus Fund II 128,618 ordinary shares Ordinary shares directly held by RA Capital Nexus Fund II, L.P.

Shares outstanding 68,642,287 ordinary shares GH Research PLC ordinary shares outstanding per Form 6-K filed August 6, 2026

Key Terms

beneficial owner, shared voting power, shared dispositive power, Section 13(d) of the Act, +1 more

5 terms

beneficial owner regulatory

"may be deemed a beneficial owner, for purposes of Section 13(d) of the Act"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

shared voting power regulatory

"Shared Voting Power 4,897,182.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power regulatory

"Shared Dispositive Power 4,897,182.00"

Section 13(d) of the Act regulatory

"for purposes of Section 13(d) of the Act, of any securities"

Report of Foreign Issuer on Form 6-K regulatory

"outstanding as Issuer's Report of Foreign Issuer on Form 6-K filed"

FAQ

What percentage of GHRS does RA Capital Management report owning in this Schedule 13G/A?

RA Capital Management and affiliates report beneficial ownership of 7.1% of GH Research PLC’s ordinary shares, corresponding to 4,897,182 shares based on 68,642,287 shares outstanding as disclosed in a Form 6-K filed August 6, 2026.

How many GHRS shares are held by RA Capital Healthcare Fund, L.P.?

RA Capital Healthcare Fund, L.P. directly holds 4,768,564 ordinary shares of GH Research PLC. Voting and investment authority over these shares has been delegated to RA Capital Management, L.P. under an investment advisory arrangement described in the filing.

What is the total number of GHRS shares reported by RA Capital entities?

The RA Capital complex reports 4,897,182 ordinary shares of GH Research PLC. This total includes 4,768,564 shares held by RA Capital Healthcare Fund, L.P. and 128,618 shares held by RA Capital Nexus Fund II, L.P., over which RA Capital has delegated authority.

On what share count is RA Capital’s 7.1% GHRS ownership based?

The 7.1% ownership figure is based on 68,642,287 ordinary shares of GH Research PLC outstanding. That outstanding share number comes from the company’s Report of Foreign Issuer on Form 6-K filed with the SEC on August 6, 2026.

Do RA Capital and its principals claim to be a group for GHRS under Section 13(d)?

The reporting persons expressly disclaim status as a “group” for Section 13(d) purposes. RA Capital, Peter Kolchinsky, and Rajeev Shah also disclaim beneficial ownership of the reported GH Research PLC securities except for determining their Section 13(d) filing obligations.

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Available on EDGAR 08/14/2026 - 06:39 PM Accepted by SEC EDGAR 08/14/2026 - 06:38 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 8)

GH Research PLC

(Name of Issuer)

Ordinary Shares, Nominal value of $0.025 per share

(Title of Class of Securities)

G3855L106

(CUSIP Number)

08/12/2026

(Date of Event Which Requires Filing of this Statement)

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

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): G3855L106

1

Names of Reporting Persons

RA Capital Management, L.P.

2

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

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 4,897,182.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,897,182.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,897,182.00

10

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

11

Percent of class represented by amount in row (9)

7.1 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP Number(s): G3855L106

1

Names of Reporting Persons

Peter Kolchinsky

2

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

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 4,897,182.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,897,182.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,897,182.00

10

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

11

Percent of class represented by amount in row (9)

7.1 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP Number(s): G3855L106

1

Names of Reporting Persons

Rajeev Shah

2

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

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 4,897,182.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,897,182.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,897,182.00

10

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

11

Percent of class represented by amount in row (9)

7.1 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP Number(s): G3855L106

1

Names of Reporting Persons

RA Capital Healthcare Fund, L.P.

2

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

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 4,768,564.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,768,564.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,768,564.00

10

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

11

Percent of class represented by amount in row (9)

6.9 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: GH Research PLC
(b)	Address of issuer's principal executive offices: Joshua Dawson House, Dawson Street, Dublin 2, L2, D02 RY95.
Item 2.
(a)	Name of person filing: The names of the persons filing this report (collectively, the "Reporting Persons") are: RA Capital Management, L.P. ("RA Capital") Peter Kolchinsky Rajeev Shah RA Capital Healthcare Fund, L.P. (the "Fund") The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13G/A.
(b)	Address or principal business office or, if none, residence: The address of the principal business office of each of the Reporting Persons is: c/o RA Capital Management, L.P., 200 Berkeley Street, 18th Floor, Boston MA 02116
(c)	Citizenship: RA Capital and the Fund are Delaware limited partnerships. Dr. Kolchinsky and Mr. Shah are United States citizens.
(d)	Title of class of securities: Ordinary Shares, Nominal value of $0.025 per share
(e)	CUSIP No.: G3855L106
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: Row 9 of each Reporting Person's cover page to this Schedule 13G/A sets forth the aggregate number of ordinary shares of the Issuer beneficially owned by such Reporting Person and is incorporated by reference. The Reporting Persons' ownership of the Issuer's securities includes (i) 4,768,564 ordinary shares directly held by the Fund, and (ii) 128,618 ordinary shares directly held by RA Capital Nexus Fund II, L.P. (the "Nexus Fund II"). RA Capital Healthcare Fund GP, LLC is the general partner of the Fund and RA Capital Nexus Fund II GP, LLC is the general partner of the Nexus Fund II. The general partner of RA Capital is RA Capital Management GP, LLC, of which Dr. Kolchinsky and Mr. Shah are the controlling persons. RA Capital serves as investment adviser for each of the Fund and the Nexus Fund II and may be deemed a beneficial owner, for purposes of Section 13(d) of the Act, of any securities of the Issuer held by the Fund or the Nexus Fund II. Each of the Fund and the Nexus Fund II has delegated to RA Capital the sole power to vote and the sole power to dispose of all securities held in its portfolio, including the ordinary shares of the Issuer reported herein. Because each of the Fund and the Nexus Fund II has divested itself of voting and investment power over the reported securities it holds and may not revoke that delegation on less than 61 days' notice, each of the Fund and the Nexus Fund II disclaims beneficial ownership of the securities it holds for purposes of Section 13(d) of the Act and therefore disclaims any obligation to report ownership of the reported securities under Section 13(d) of the Act. As managers of RA Capital, Dr. Kolchinsky and Mr. Shah may be deemed beneficial owners, for purposes of Section 13(d) of the Act, of any securities of the Issuer beneficially owned by RA Capital. RA Capital, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of the securities reported in this Schedule 13G other than for the purpose of determining their obligations under Section 13(d) of the Act, and the filing of this Schedule 13G shall not be deemed an admission that either RA Capital, Dr. Kolchinsky, or Mr. Shah is the beneficial owner of such securities for any other purpose.
(b)	Percent of class: Row 11 of each Reporting Person's cover page to this Schedule 13G/A sets forth the percentage of the ordinary shares of the Issuer beneficially owned by such Reporting Person and is incorporated by reference. The percentage set forth in Row 11 of each Reporting Person's cover page is based upon 68,642,287 ordinary shares of the Issuer outstanding as Issuer's Report of Foreign Issuer on Form 6-K filed with the Securities and Exchange Commission (the "SEC") on August 6, 2026.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Row 5 of each Reporting Person's cover page to this Schedule 13G/A sets forth the sole power to vote or to direct the vote of securities of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
	(ii) Shared power to vote or to direct the vote: Row 6 of each Reporting Person's cover page to this Schedule 13G/A sets forth the shared power to vote or to direct the vote of securities of the Issuer beneficially owned by such Reporting Person as of and is incorporated by reference.
	(iii) Sole power to dispose or to direct the disposition of: Row 7 of each Reporting Person's cover page to this Schedule 13G/A sets forth the sole power to dispose or to direct the disposition of securities of the Issuer beneficially owned by such Reporting Person as of and is incorporated by reference.
	(iv) Shared power to dispose or to direct the disposition of: Row 8 of each Reporting Person's cover page to this Schedule 13G/A sets forth the shared power to dispose or to direct the disposition of securities of the Issuer beneficially owned by such Reporting Person as of and is incorporated by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	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.

Certifications:

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.

RA Capital Management, L.P.

Signature:	/s/ Peter Kolchinsky
Name/Title:	By Peter Kolchinsky, Authorized Signatory
Date:	08/14/2026

Peter Kolchinsky

Signature:	/s/ Peter Kolchinsky
Name/Title:	Peter Kolchinsky
Date:	08/14/2026

Rajeev Shah

Signature:	/s/ Rajeev Shah
Name/Title:	Rajeev Shah
Date:	08/14/2026

RA Capital Healthcare Fund, L.P.

Signature:	/s/ Peter Kolchinsky
Name/Title:	By RA Capital Healthcare Fund GP, LLC, its General Partner, By Peter Kolchinsky, Manager
Date:	08/14/2026

Exhibit Information

Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to Schedule 13G/A filed on May 15, 2025)