15-12G 1 tm263425d1_1512g.htm 15-12G

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION

UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934

OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934.

Commission File Number: 001-38129

Mersana Therapeutics, Inc.

(Exact name of registrant as specified in its charter)

840 Memorial Drive

Cambridge, Massachusetts 02139

Telephone: (617) 498-0020
(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Common Stock, par value $0.0001 per share
(Title of each class of securities covered by this Form)

None
(Titles of all other classes of securities for which a duty to file reports under Section 13(a) or 15(d) remains)

Please place an X in the box(es) to designate the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports:

	Rule 12g-4(a)(l)	x
	Rule 12g-4(a)(2)	¨
	Rule 12h-3(b)(l)(i)	x
	Rule 12h-3(b)(l)(ii)	¨
	Rule 15d-6	¨
	Rule 15d-22(b)	¨

Approximate number of holders of record as of the certification or notice date: One (1) holder.

Pursuant to the requirements of the Securities Exchange Act of 1934, Mersana Therapeutics, Inc. has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person.

	Mersana Therapeutics, Inc.

	By:	/s/ Charles N. York II
	Name: Charles N. York II, M.B.A.
	Title: Chief Executive Officer

Date: January 16, 2026

SEC Form 15-12G filed by Mersana Therapeutics Inc.