Adage Reveals 6.27% Stake in ProQR, Reporting 6.6M Shares

Adage Capital Management reports a passive beneficial ownership position in ProQR Therapeutics N.V., holding 6,601,938 ordinary shares, which represents 6.27% of the company's 105,212,527 ordinary shares outstanding (per the company's annual report).

Rhea-AI Filing Summary

Adage Capital Management reports a passive beneficial ownership position in ProQR Therapeutics N.V., holding 6,601,938 ordinary shares, which represents 6.27% of the company's 105,212,527 ordinary shares outstanding (per the company's annual report). The shares are held directly by Adage Capital Partners, L.P., for which Adage Capital Management acts as investment manager, and the filing shows shared voting and shared dispositive power for the reported position.

The Schedule 13G filing is made as a passive disclosure: the Reporting Persons certify the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of the issuer. The filing names the reporting entities and key individuals and identifies their principal business address.

Positive

• Adage holds 6,601,938 shares, representing 6.27% of ProQR's outstanding ordinary shares
• Position filed on Schedule 13G indicating the holding is passive and certified not to be for control purposes

Negative

• None.

Insights

Financial Analyst

Adage holds a meaningful 6.27% passive stake in ProQR; this shows notable institutional interest without an intent to seize control.

The 6,601,938-share position equals 6.27% of the 105,212,527 shares referenced in the company's annual report, a level that typically warrants market attention because it crosses the 5% disclosure threshold. As this Schedule 13G indicates passive ownership, there is no stated plan to pursue control, which reduces immediate governance disruption risk. For investors, the disclosure signals that a seasoned institutional manager has a sizable economic exposure to PRQR equity, which may influence liquidity and monitoring activities but is not presented as an activist stake.

Corporate Governance Expert

This is a material ownership disclosure (>5%) filed as passive; it raises governance monitoring but does not indicate an intent to change control.

The filing attributes shared voting and shared dispositive power over 6,601,938 ordinary shares held by an affiliate structure (Adage Capital Partners, L.P.). Filing on Schedule 13G and the included certification state the position is held in the ordinary course and not to influence control, which classifies the holder as a passive institutional investor rather than an activist. Materiality arises from the >5% threshold, meaning the holder will be visible to other stakeholders and subject to public scrutiny, but the filing itself contains no operational or governance demands.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many ProQR (PRQR) shares does Adage Capital report owning?

Adage Capital reports beneficial ownership of 6,601,938 ordinary shares of ProQR.

What percentage of ProQR does Adage's holding represent?

The reported position represents 6.27% of the class, based on 105,212,527 shares referenced in the filing.

Is Adage reporting the stake as passive or active ownership?

The stake is reported on Schedule 13G and the Reporting Persons certify the securities are held in the ordinary course of business and not to influence control.

Through which entity are the shares held?

The ordinary shares are directly held by Adage Capital Partners, L.P., for which Adage Capital Management, L.P. acts as investment manager.

Who are the named reporting persons in the filing?

The filing names Adage Capital Management, L.P., and individuals Robert Atchinson and Phillip Gross as Reporting Persons.

AI-generated analysis. How Rhea-AI works. Not financial advice.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 08/12/2025 - 09:03 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

ProQR Therapeutics N.V.

(Name of Issuer)

Ordinary Shares, nominal value 0.04 euro per share

(Title of Class of Securities)

N71542109

(CUSIP Number)

06/30/2025

(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)

SCHEDULE 13G

CUSIP No. N71542109

1

Names of Reporting Persons

Adage 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 6,601,938.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,601,938.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,601,938.00

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)

6.27 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP No. N71542109

1

Names of Reporting Persons

Robert Atchinson

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 6,601,938.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,601,938.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,601,938.00

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)

6.27 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP No. N71542109

1

Names of Reporting Persons

Phillip Gross

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 6,601,938.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,601,938.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,601,938.00

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)

6.27 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: ProQR Therapeutics N.V.
(b)	Address of issuer's principal executive offices: Zernikedreef 9, 2333 CK Leiden, The Netherlands
Item 2.
(a)	Name of person filing: This statement is filed by: (i) Adage Capital Management, L.P., a Delaware limited partnership ("ACM"), as the investment manager of Adage Capital Partners, L.P., a Delaware limited partnership ("ACP"), with respect to the ordinary shares, par value (euro)0.040.04 per share ("Ordinary Shares") of ProQR Therapeutics N.V., a Dutch company (the "Company") directly held by ACP; (ii) Robert Atchinson ("Mr. Atchinson"), as (1) managing member of Adage Capital Advisors, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACA"), managing member of Adage Capital Partners GP, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACPGP"), general partner of ACP and (2) managing member of Adage Capital Partners LLC, a Delaware limited liability company ("ACPLLC"), general partner of ACM, with respect to the Ordinary Shares directly held by ACP; and (iii) Phillip Gross ("Mr. Gross"), as (1) managing member of ACA, managing member of ACPGP and (2) managing member of ACPLLC, general partner of ACM, with respect to the Ordinary Shares directly held by ACP. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party. The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of the securities reported herein.
(b)	Address or principal business office or, if none, residence: The address of the business office of each of the Reporting Persons is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.
(c)	Citizenship: ACM is a limited partnership organized under the laws of the State of Delaware. Messrs. Gross and Atchinson are citizens of the United States.
(d)	Title of class of securities: Ordinary Shares, nominal value 0.04 euro per share
(e)	CUSIP No.: N71542109
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 information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 105,212,527 Ordinary Shares outstanding as of December 31, 2024, as reported in the Company's Annual report on Form 20-F for the fiscal year ended December 31, 2024, filed with the Securities and Exchange Commission on March 13, 2025.
(b)	Percent of class: 6.27%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. See Item 2(a).
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 acquired and are held in the ordinary course of business and 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.

Adage Capital Management, L.P.

Signature:	/s/ Robert Atchinson
Name/Title:	By: Adage Capital Partners LLC, its General Partner, By: Robert Atchinson, its Managing Member
Date:	08/12/2025

Robert Atchinson

Signature:	/s/ Robert Atchinson
Name/Title:	Robert Atchinson, individually
Date:	08/12/2025

Phillip Gross

Signature:	/s/ Phillip Gross
Name/Title:	Phillip Gross, individually
Date:	08/12/2025