MeiraGTx Holdings plc ownership disclosure: Adage Capital Management, L.P. and related reporting persons report 4,000,000 Ordinary Shares, representing 4.91% of the class. The percentage is calculated using 81,446,126 Ordinary Shares outstanding as of March 30, 2026, per the company's Form 10-K.
The filing (Amendment No. 6 to a Schedule 13G) attributes shared voting and shared dispositive power over the 4,000,000 shares to Adage and individuals Robert Atchinson and Phillip Gross. The business address for the reporting persons is noted as 200 Clarendon Street, Boston, Massachusetts.
Positive
None.
Negative
None.
Insights
Adage reports a sub-5% passive stake in MeiraGTx.
Adage Capital and the named managers report shared voting and dispositive power over 4,000,000 Ordinary Shares, equal to 4.91% of the class using the company's March 30, 2026 outstanding count of 81,446,126. The filing is an amended Schedule 13G disclosure.
The position size is below the 5% threshold that often triggers active reporting. Cash-flow treatment and any acquisition timing are not disclosed in the excerpt; subsequent filings would state changes in holdings.
Key Figures
Reported shares owned:4,000,000 sharesPercent of class:4.91%Shares outstanding used:81,446,126 shares+2 more
5 metrics
Reported shares owned4,000,000 sharesAmount beneficially owned by Adage and reporting persons
Percent of class4.91%Calculated using outstanding shares as of March 30, 2026
Shares outstanding used81,446,126 sharesOutstanding Ordinary Shares as of <date>March 30, 2026</date> per Form 10-K
Schedule 13G/A, Beneficially owned, Shared dispositive power
3 terms
Schedule 13G/Aregulatory
"Amendment No. 6 to a Schedule 13G is referenced on the cover page"
A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.
Beneficially ownedfinancial
"Item 4(a) states 'Amount beneficially owned' set forth in Row 9"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
Shared dispositive powerregulatory
"Cover rows list 'Shared Dispositive Power 4,000,000.00' for reporting persons"
What stake does Adage Capital report in MeiraGTx (MGTX)?
Adage Capital reports beneficial ownership of 4,000,000 Ordinary Shares, representing 4.91% of MeiraGTx's class, calculated using 81,446,126 shares outstanding as of March 30, 2026.
Who are the reporting persons on the Schedule 13G/A for MGTX?
The statement is filed by Adage Capital Management, L.P. and related persons, specifically Robert Atchinson and Phillip Gross, each reported with shared voting and dispositive power over the disclosed shares.
Does the filing show Adage has sole control over the shares?
No. The filing discloses shared voting power and shared dispositive power over the 4,000,000 shares; sole voting and sole dispositive powers are reported as 0 on the cover rows.
What outstanding share count did the Schedule 13G/A use to calculate the percentage?
The percentage calculation uses an outstanding share count of 81,446,126 Ordinary Shares as of March 30, 2026, cited from the company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025.
Is this Schedule 13G/A an initial filing or an amendment?
This is listed as Amendment No. 6 to a Schedule 13G, indicating it is an amended disclosure rather than the initial Schedule 13G filing for these reporting persons.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 6)
MeiraGTx Holdings plc
(Name of Issuer)
Ordinary Shares, par value $0.00003881 per share
(Title of Class of Securities)
G59665102
(CUSIP Number)
03/31/2026
(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):
G59665102
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
4,000,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
4,000,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,000,000.00
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)
4.91 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
G59665102
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
4,000,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
4,000,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,000,000.00
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)
4.91 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
CUSIP Number(s):
G59665102
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
4,000,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
4,000,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,000,000.00
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)
4.91 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
MeiraGTx Holdings plc
(b)
Address of issuer's principal executive offices:
655 Third Avenue, Suite 1115, New York, NY 10017
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 $0.00003881 per share ("Ordinary Shares"), of MeiraGTx Holdings plc, an exempted company incorporated under the laws of the Cayman Islands (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, par value $0.00003881 per share
(e)
CUSIP No.:
G59665102
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 81,446,126 Ordinary Shares outstanding as of March 30, 2026, as reported in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025, filed with the Securities and Exchange Commission on March 30, 2026.
(b)
Percent of class:
4.91%
(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.
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
