[SCHEDULE 13D/A] ProQR Therapeutics N.V. SEC Filing

Rhea-AI Filing Summary

Van Herk Investments and affiliated entities report beneficial ownership of 12,202,190 ordinary shares of ProQR Therapeutics N.V., representing 11.6% of the 105,344,052 shares outstanding. The Schedule 13D/A states that Van Herk Investments B.V. purchased 700,195 shares in open market transactions between June 12, 2025 and July 21, 2025 for a total net amount of $1,319,201.27, funded from its general working capital.

The filing adds that on August 19, 2025 Van Herk sent a follow-up letter urging ProQR's board to limit the terms of two directors to the 2026 AGM, explain the rationale for one reappointment, present a board rotation plan and commit to governance standards. The reporting persons state their shares were acquired for investment purposes and reserve the right to engage in communications with management, pursue transactions, buy or sell shares or use derivatives in the future.

Positive

• Significant stake: Beneficial ownership of 12,202,190 shares equals 11.6% of outstanding shares, a materially influential position
• Recent purchases: VHI acquired 700,195 shares between June 12 and July 21, 2025, showing active accumulation
• Clear governance focus: The Follow-Up Letter sets concrete governance requests, which may lead to constructive board-shareholder engagement

Negative

• Governance dispute: Public demands regarding director terms and reappointment rationale could create management distraction and shareholder uncertainty
• Potential for activist escalation: Reporting persons reserve rights to pursue transactions, proposals or derivative strategies that could increase volatility
• Concentrated ownership complexity: Multiple affiliated entities and foundations holding the stake may complicate voting dynamics and disclosure clarity

Insights

Financial Analyst

TL;DR A concentrated 11.6% stake plus recent open-market buys signals a material investor position that could affect governance and share supply.

Van Herk's 11.6% holding is large enough to influence shareholder dialogue and could pressure management on board composition and strategy. The disclosed $1.32m purchase of 700,195 shares shows recent accumulation but at a modest absolute dollar amount relative to typical biotech market caps, so immediate financial impact on liquidity is limited. The filing preserves a wide range of future actions, including additional purchases, sales, derivative usage or proposals that could create volatility. Monitor future amendments for changes in position size or explicit proposals that would be material to valuation.

Corporate Governance Expert

TL;DR Public demands for board rotation and explanations for director reappointment represent targeted governance activism from a substantial shareholder group.

The Follow-Up Letter's requests—limiting two directors' terms to the 2026 AGM, requesting justification for a specific reappointment, and seeking a structured board rotation plan—signal organized governance pressure rather than passive ownership. The structure of the reporting group (multiple affiliated entities and foundations) and the explicit disclaimer of beneficial ownership by some entities is typical in family/holding structures but consolidates voting influence. This increases the likelihood of shareholder dialogue or proxy contests if the board does not engage. The filing appropriately reserves strategic options, which is consistent with preparatory activism.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)

ProQR Therapeutics N.V.

(Name of Issuer)

Ordinary Shares, nominal value Euro 0.04 per share

(Title of Class of Securities)

N71542109

(CUSIP Number)

Van Herk Investments B.V.
Lichtenauerlaan 30,
Rotterdam, P7, 3062 ME
31-10-241-1555

Evan S. Simpson
1 New Fetter Lane,
London, X0, EC4A 1AN
44 20 795984-26

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

08/19/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Van Herk Investments B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 12,202,190.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 12,202,190.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of ProQR Therapeutics N.V. (the "Issuer") issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Van Herk Investments THI B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Van Herk Private Equity Investments B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Stichting Administratiekantoor Penulata

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Van Herk Management Services B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Onroerend Goed Beheer- en Beleggingsmaatschappij A. van Herk B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

A. van Herk Holding B.V.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Stichting Administratiekantoor Abchrys

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on August 7, 2025.

SCHEDULE 13D

CUSIP No. N71542109

1

Name of reporting person

Adrianus van Herk

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

BK, WC, PF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NETHERLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 12,202,190.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 12,202,190.00

11

Aggregate amount beneficially owned by each reporting person

12,202,190.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

11.6 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

* Based on 105,344,052 ordinary shares, nominal value Euro 0.04 per share, of the Issuer issued and outstanding as of June 30, 2025, as reported in the Issuer's Form 6-K filed with the SEC on May 8, 2025.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Ordinary Shares, nominal value Euro 0.04 per share
(b)	Name of Issuer: ProQR Therapeutics N.V.
(c)	Address of Issuer's Principal Executive Offices: Zernikedreef 9, Leiden, NETHERLANDS , 2333 CK.
Item 1 Comment: This Schedule 13D/A (this "Amendment") amends the Schedule 13D (the "Original Schedule 13D") filed on May 28, 2025. Items 1, 4, 5 and 7 of the Original Schedule 13D are hereby amended and supplemented to the extent hereinafter expressly set forth in this Amendment. Except as amended hereby, the original disclosure set forth in the Original Schedule 13D shall remain unchanged. All capitalized terms used and not expressly defined herein have the respective meanings ascribed to such terms in the Original Schedule 13D.
Item 2.	Identity and Background
(a)	The information previously provided in response to Item 2 is hereby amended and restated by replacing the text thereof in its entirety with the following: This statement is being filed by (i) Van Herk Investments B.V., a private company with limited liability incorporated under the laws of the Netherlands ("VHI"), with respect to Ordinary Shares, nominal value Euro 0.04 per share (the "Ordinary Shares"), beneficially owned by it, (ii) Van Herk Investments THI B.V., a private company with limited liability incorporated under the laws of the Netherlands ("VHIT"), with respect to Ordinary Shares beneficially owned by VHI, (iii) Van Herk Private Equity Investments B.V., a private company with limited liability incorporated under the laws of the Netherlands ("VHPI"), with respect to Ordinary Shares beneficially owned by VHI and VHIT, (iv) Stichting Administratiekantoor Penulata, a foundation organized under the laws of the Netherlands ("Penulata"), with respect to Ordinary Shares beneficially owned by VHI, VHIT and VHPI, (v) Van Herk Management Services B.V., a private company with limited liability incorporated under the laws of the Netherlands ("VHMS"), with respect to Ordinary Shares beneficially owned by VHI, VHIT and VHPI, (vi) Onroerend Goed Beheer- en Beleggingsmaatschappij A. van Herk B.V., a private company with limited liability incorporated under the laws of the Netherlands ("OGBBA"), with respect to Ordinary Shares beneficially owned by VHI, VHIT, VHPI and VHMS, (vii) A. van Herk Holding B.V., a private company with limited liability incorporated under the laws of the Netherlands ("Holdings"), with respect to Ordinary Shares beneficially owned by VHI, VHIT, VHPI, VHMS and OGBBA, (viii) Stichting Administratiekantoor Abchrys, a foundation organized under the laws of the Netherlands ("Abchrys"), with respect to Ordinary Shares beneficially owned by VHI, VHIT, VHPI, VHMS, OGBBA and Holdings, and (ix) Adrianus van Herk ("Mr. van Herk") with respect to Ordinary Shares beneficially owned by VHI, VHIT, VHPI, VHMS, OGBBA, Holdings, Penulata and Abchrys. Each of Mr. van Herk, VHIT, VHPI, Penulata, VHMS, OGBBA, Holdings and Abchrys disclaims beneficial ownership of the securities covered by this statement.
(b)	The principal business address of each of Mr. van Herk, VHI, VHIT, VHPI, Penulata, VHMS, OGBBA, Holdings and Abchrys is: Lichtenauerlaan 30 3062 ME Rotterdam The Netherlands
(c)	Mr. van Herk is (i) an investor, (ii) the holder of all of the depositary receipts issued by Penulata and Abchrys, (iii) the sole board member of Penulata and Abchrys, and (iv) the sole managing director of VHMS, OGBBA and Holdings. Penulata holds substantially all of the issued and outstanding shares of VHPI. VHPI is the sole shareholder of VHIT. VHIT is the sole shareholder of VHI. VHI is principally engaged in making investments. Abchrys holds substantially all of the issued and outstanding shares of Holdings. Holdings is the sole shareholder of OGBBA. OGBBA is the sole shareholder of VHMS and is principally engaged in making investments. VHMS is the sole managing director of VHI, VHIT and VHPI.
(d)	During the last five years, none of the Reporting Persons, nor, to the knowledge of the Reporting Persons, none of the executive officers or directors of the Reporting Persons, if applicable, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the last five years, none of the Reporting Persons, nor, to the knowledge of the Reporting Persons, none of the executive officers or directors of the Reporting Persons, if applicable, has been a party to a civil proceeding of a judicial or administrative body of a competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.
(f)	Each of VHI, VHIT, VHPI, VHMS, OGBBA and Holdings is a private company with limited liability incorporated under the laws of the Netherlands. Penulata and Abchrys are Netherlands foundations. Mr. van Herk is a citizen of the Netherlands.
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 of the Schedule 13D is amended by adding the following: From June 12, 2025 to July 21, 2025, VHI effected open market transactions in Ordinary Shares for its own account and ultimately acquired an aggregate of 700,195 Ordinary Shares for an aggregate net amount of $1,319,201.27. The sources of the funding for the purchase of Ordinary Shares were the general working capital of VHI.
Item 4.	Purpose of Transaction
	Item 4 of the Schedule 13D is amended by adding the following: On August 19, 2025, VHI sent a follow-up letter (the "Follow-Up Letter") to the Issuer's board of directors reiterating VHI's position that the Issuer had failed to fulfil its corporate governance duties towards the Issuer's stakeholders by failing to withdraw agenda items proposing the reappointment to the board of directors of Mr. James Shannon ("Shannon") and Mr. Daniel de Boer ("De Boer") at the Issuer's June 3, 2025 annual general meeting ("AGM"), contrary to the Dutch Corporate Governance Code (the "CGC"), the Issuer's Board Rules and the prior request to withdraw such agenda items from VHI in its initial May 23, 2025 letter to the Issuer's board of directors. In the Follow-Up Letter, VHI further called on the board of directors of the Issuer to publicly: - announce that Shannon and De Boer will only serve their current terms until the 2026 AGM, at which point their potential reappointments will be considered in consultation with shareholders; - provide a clear explanation of the rationale for the reappointment of De Boer, including how this reappointment aligns with the Issuer and its stakeholders' long-term interests; - commit to presenting a structured and transparent plan for board rotation in advance of the 2026 AGM; and - commit to future compliance with the Board Rules, the CGC and the highest standards of Dutch and U.S. corporate governance generally. A copy of the Follow-Up Letter is filed as an exhibit herewith and is incorporated herein by reference. The Reporting Persons acquired the Ordinary Shares reported herein for investment purposes in the ordinary course of business. The Reporting Persons intend to review their investment in the Issuer on a continuing basis. Depending on various factors including, without limitation, the Issuer's financial position and investment strategy, the price levels of the Ordinary Shares, conditions in the securities markets and general economic and industry conditions, the Reporting Persons may in the future take such actions with respect to their investment in the Issuer as they deem appropriate including, without limitation, engaging in communications with management and the board of directors of the Issuer, engaging in discussions with stockholders of the Issuer or other third parties about the Issuer and the Reporting Persons' investment, including potential business combinations or dispositions involving the Issuer or certain of its businesses, making recommendations or proposals to the Issuer concerning changes to the capitalization, ownership structure, board structure (including board composition), potential business combinations or dispositions involving the Issuer or certain of its businesses, or suggestions for improving the Issuer's financial and/or operational performance, purchasing additional Ordinary Shares, selling some or all of their Ordinary Shares, engaging in short selling of or any hedging or similar transaction with respect to the Ordinary Shares, including swaps and other derivative instruments, or changing their intention with respect to any and all matters referred to in Item 4.
Item 5.	Interest in Securities of the Issuer
(a)	The information previously provided in response to Item 5 is hereby amended and restated by replacing the text thereof in its entirety with the following: The information set forth in or incorporated by reference in Items 2, 3, 4 and 6 and on the cover pages of this Schedule 13D is incorporated by reference in its entirety into this Item 5.
(b)	The information set forth in or incorporated by reference in Items 2, 3, 4 and 6 and on the cover pages of this Schedule 13D is incorporated by reference in its entirety into this Item 5.
(c)	Except as set forth in this Schedule 13D, no transactions in Ordinary Shares of the Issuer have been effected during the past sixty days by any of the Reporting Persons.
(d)	Except as set forth herein, to the knowledge of the Reporting Persons, no other person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, any securities of the Issuer beneficially owned by the Reporting Persons as described in this Item 5.
(e)	Not applicable.
Item 7.	Material to be Filed as Exhibits.
	Item 7 of the Schedule 13D is amended by adding the following: 99.1* Letter, dated August 19, 2025, from Van Herk Investments B.V. to the board of directors of ProQR Therapeutics N.V. * Filed herewith.

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.

Van Herk Investments B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Van Herk Investments THI B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Van Herk Private Equity Investments B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Stichting Administratiekantoor Penulata

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Van Herk Management Services B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Onroerend Goed Beheer- en Beleggingsmaatschappij A. van Herk B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

A. van Herk Holding B.V.

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Stichting Administratiekantoor Abchrys

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Adrianus van Herk

Signature:	/s/ Erik G.A. Esveld
Name/Title:	Erik G.A. Esveld/Attorney-In-Fact*
Date:	08/20/2025

Comments accompanying signature:

* Pursuant to a Power of Attorney, dated as of September 16, 2019, by and among the Reporting Persons.

FAQ

How many ProQR (PRQR) shares does Van Herk report owning?

The reporting persons beneficially own 12,202,190 ordinary shares, representing 11.6% of the 105,344,052 shares outstanding.

When and how many shares did Van Herk recently buy in PRQR?

Van Herk Investments B.V. acquired 700,195 shares in open market transactions from June 12, 2025 to July 21, 2025 for an aggregate net amount of $1,319,201.27.

What governance actions did Van Herk request from ProQR's board?

In an August 19, 2025 letter Van Herk asked the board to: limit two directors' service to the 2026 AGM, explain the rationale for one reappointment, present a board rotation plan and commit to compliance with board rules and governance standards.

What future actions did the reporting persons reserve the right to take?

They may engage with management or shareholders, propose changes to board or capital structure, pursue business combinations or dispositions, buy or sell shares, or use derivatives and hedging strategies.

What was the source of funds for Van Herk's purchases of PRQR shares?

The purchases were funded from the general working capital of Van Herk Investments B.V.

Where is ProQR Therapeutics N.V. incorporated and what class of security is involved?

The issuer is ProQR Therapeutics N.V. and the filing concerns its ordinary shares, nominal value €0.04 per share.