Form SC 13G/A - Statement of Beneficial Ownership by Certain Investors: [Amend]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Mersana Therapeutics, Inc.

(Name of Issuer)

Common stock, $0.0001 par value per share

(Title of Class of Securities)

59045L106

(CUSIP Number)

September 30, 2024

(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)

	x	Rule 13d-1(c)

	¨	Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in 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).

CUSIP No. 59045L106
1.	Names of Reporting Persons Nextech Crossover I SCSp
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC Use Only
4.	Citizenship or Place of Organization Luxembourg

Number of

Beneficially

Owned by

Each

Reporting

Person With

Sole Voting Power

12,067,246 shares

Shared Voting Power

Sole Dispositive Power

12,067,246 shares

Shared Dispositive Power

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 12,067,246 shares
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) ¨
11.	Percent of Class Represented by Amount in Row (9) 9.8% (2)
12.	Type of Reporting Person (See Instructions) PN

(1)

This Schedule 13G is filed by Nextech Crossover I SCSP (“Nextech Crossover LP”), Nextech Crossover I GP S.à r.l. (“Nextech Crossover GP”), Ian Charoub, (“Charoub”), Costas Constantinides (“Constantinides”) and Rocco Sgobbo (“Sgobbo” and, with Nextech Crossover LP, Nextech Crossover GP, Charoub and Constantinides, collectively, the “Reporting Persons”). The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)

The percent of class was calculated based on 122,675,051 shares of Common Stock outstanding as of August 9, 2024, as reported in the Issuer’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (the “SEC”) on August 13, 2024.

CUSIP No. 59045L106
1.	Names of Reporting Persons Nextech Crossover I GP S.à r.l.
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC Use Only
4.	Citizenship or Place of Organization Luxembourg

Number of

Beneficially

Owned by

Each

Reporting

Person With

Sole Voting Power

12,067,246 shares

Shared Voting Power

Sole Dispositive Power

12,067,246 shares

Shared Dispositive Power

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 12,067,246 shares
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) ¨
11.	Percent of Class Represented by Amount in Row (9) 9.8% (2)
12.	Type of Reporting Person (See Instructions) OO

(1)

This Schedule 13G is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)

CUSIP No. 59045L106
1.	Names of Reporting Persons Ian Charoub
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC Use Only
4.	Citizenship or Place of Organization Sweden

Number of

Beneficially

Owned by

Each

Reporting

Person With

Sole Voting Power

Shared Voting Power

12,067,246 shares

Sole Dispositive Power

Shared Dispositive Power

12,067,246 shares

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 12,067,246 shares
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) ¨
11.	Percent of Class Represented by Amount in Row (9) 9.8% (2)
12.	Type of Reporting Person (See Instructions) IN

(1)

This Schedule 13G is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)

CUSIP No. 59045L106
1.	Names of Reporting Persons Costas Constantinides
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC Use Only
4.	Citizenship or Place of Organization Cyprus

Number of

Beneficially

Owned by

Each

Reporting

Person With

Sole Voting Power

Shared Voting Power

12,067,246 shares

Sole Dispositive Power

Shared Dispositive Power

12,067,246 shares

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 12,067,246 shares
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) ¨
11.	Percent of Class Represented by Amount in Row (9) 9.8% (2)
12.	Type of Reporting Person (See Instructions) IN

(1)

This Schedule 13G is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)

CUSIP No. 59045L106
1.	Names of Reporting Persons Rocco Sgobbo
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC Use Only
4.	Citizenship or Place of Organization Switzerland

Number of

Beneficially

Owned by

Each

Reporting

Person With

Sole Voting Power

Shared Voting Power

12,067,246 shares

Sole Dispositive Power

Shared Dispositive Power

12,067,246 shares

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 12,067,246 shares
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) ¨
11.	Percent of Class Represented by Amount in Row (9) 9.8% (2)
12.	Type of Reporting Person (See Instructions) IN

(1)

This Schedule 13G is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)

Item 1.
	(a)	Name of Issuer Mersana Therapeutics, Inc.
	(b)	Address of Issuer’s Principal Executive Offices 840 Memorial Drive Cambridge, MA 02139

Item 2.

	(a)	Name of Person Filing Nextech Crossover I SCSp (“Nextech Crossover LP”) Nextech Crossover I GP S.à r.l. (“Nextech Crossover GP”) Ian Charoub (“Charoub”) Costas Constantinides (“Constantinides”) Rocco Sgobbo (“Sgobbo”)
	(b)	Address of Principal Business Office or, if none, Residence 8 rue Lou Hemmer L-1748 Luxembourg-Findel Grand-Duché de Luxembourg

(c)	Citizenship

	Name	Citizenship or Place of Organization
	Nextech Crossover LP	Luxembourg
	Nextech Crossover GP	Luxembourg
	Charoub	Sweden
	Constantinides	Cyprus
	Sgobbo	Switzerland

	(d)	Title of Class of Securities Common Stock, $0.0001 par value (“Common Stock”)
	(e)	CUSIP Number 59045L106

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:

	Not applicable

Item 4.

Ownership

The following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1 is provided as of November 14, 2024:

Reporting Persons	Shares Held Directly		Sole Voting Power		Shared Voting Power		Sole Dispositive Power		Shared Dispositive Power		Beneficial Ownership		Percentage of Class (2)
Nextech Crossover LP (1)		12,067,246		12,067,246				12,067,246				12,067,246		9.8	%
Nextech Crossover GP (1)				12,067,246				12,067,246				12,067,246		9.8	%
Charoub (1)						12,067,246				12,067,246		12,067,246		9.8	%
Constantinides (1)						12,067,246				12,067,246		12,067,246		9.8	%
Sgobbo (1)						12,067,246				12,067,246		12,067,246		9.8	%

(1)

The shares are held by Nextech Crossover LP. Nextech Crossover GP serves as the sole general partner of Nextech Crossover LP and has sole voting and investment control over the shares owned by Nextech Crossover LP and may be deemed to own beneficially the shares held by Nextech Crossover LP. Nextech Crossover GP owns no securities of the Issuer directly. Charoub, Constantinides and Sgobbo are members of the board of managers of Nextech Crossover GP and share voting and dispositive power over the shares held by Nextech Crossover LP, and may be deemed to own beneficially the shares held by Nextech Crossover LP. Charoub, Constantinides and Sgobbo own no securities of the Issuer directly.

(2)

Item 5.	Ownership of Five Percent or Less of a Class

	If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following ¨


Item 6.	Ownership of More than Five 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.	Certification

	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 such purpose or effect.

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.

Dated: November 14, 2024

Nextech Crossover I SCSp

By:	Nextech Crossover I GP S.à r.l.
its	General Partner

By:	/s/ Ian Charoub
	Name:	Ian Charoub
	Title:	Manager

By:	/s/ Costas Constantinides
	Name:	Costas Constantinides
	Title:	Manager

Nextech Crossover I GP S.à r.l.

By:	/s/ Ian Charoub
	Name:	Ian Charoub
	Title:	Manager

By:	/s/ Costas Constantinides
	Name:	Costas Constantinides
	Title:	Manager

/s/ Ian Charoub
Ian Charoub

/s/ Costas Constantinides
Costas Constantinides

/s/ Rocco Sgobbo
Rocco Sgobbo

	ATTENTION
Intentional misstatements or omissions of fact constitute Federal Criminal Violations (See 18 U.S.C. 1001).

Exhibit(s):

Joint Filing Agreement

EXHIBIT A

JOINT FILING AGREEMENT

We, the undersigned, hereby express our agreement that the attached Schedule 13G (or any amendments thereto) relating to the Common Stock of Mersana Therapeutics, Inc. is filed on behalf of each of us.

Dated: November 14, 2024

Nextech Crossover I SCSp

By:	Nextech Crossover I GP S.à r.l.
its	General Partner

By:	/s/ Ian Charoub
	Name:	Ian Charoub
	Title:	Manager

By:	/s/ Costas Constantinides
	Name:	Costas Constantinides
	Title:	Manager

Nextech Crossover I GP S.à r.l.

By:	/s/ Ian Charoub
	Name:	Ian Charoub
	Title:	Manager

By:	/s/ Costas Constantinides
	Name:	Costas Constantinides
	Title:	Manager

/s/ Ian Charoub
Ian Charoub

/s/ Costas Constantinides
Costas Constantinides

/s/ Rocco Sgobbo
Rocco Sgobbo