15-12G

Date: August 21, 2025

TURNSTONE BIOLOGICS CORP.

/s/ Owen Hughes

Name: Owen Hughes

Title: President, Treasurer and Secretary

15-12G 1 d930633d1512g.htm 15-12G 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.

001-41747

Commission File Number

TURNSTONE BIOLOGICS CORP.

(Exact name of registrant as specified in its charter)

2200 Powell Street, Suite 310

Emeryville, California 94608

(510) 204-7200

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Common Stock, $0.001 par value 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)(1)		☒
Rule 12g-4(a)(2)		☐
Rule 12h-3(b)(1)(i)		☒
Rule 12h-3(b)(1)(ii)		☐
Rule 15d-6		☐
Rule 15d-22(b)		☐

Approximate number of holders of record as of the certification or notice date: One

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

SEC Form 15-12G filed by Turnstone Biologics Corp.