# EDGAR Filing Document

**Accession Number:** 0001764974
**File Stem:** 0001193125-25-184743
**Filing Date:** 2025-8
**Character Count:** 2823
**Document Hash:** 55f5ff8daae1189edf0b38f5da314835
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-184743.hdr.sgml**: 20250821

**ACCESSION NUMBER**: 0001193125-25-184743

**CONFORMED SUBMISSION TYPE**: 15-12G

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250821

**DATE AS OF CHANGE**: 20250821

**EFFECTIVENESS DATE**: 20250821

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Turnstone Biologics Corp.
- **CENTRAL INDEX KEY:** 0001764974
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 832909368
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 15-12G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41747
- **FILM NUMBER:** 251238561

**BUSINESS ADDRESS:**
- **STREET 1:** 9310 ATHENA CIRCLE, SUITE 300
- **CITY:** LA JOLLA
- **STATE:** CA
- **ZIP:** 92037
- **BUSINESS PHONE:** 347-897-5988

**MAIL ADDRESS:**
- **STREET 1:** 9310 ATHENA CIRCLE, SUITE 300
- **CITY:** LA JOLLA
- **STATE:** CA
- **ZIP:** 92037

**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.

---

| | | |
|:---|:---|:---|
| Date: August 21, 2025 | **TURNSTONE BIOLOGICS CORP.** | **TURNSTONE BIOLOGICS CORP.** |
|  | By: | /s/ Owen Hughes |
|  |  | Name: Owen Hughes |
|  |  | Title: *President, Treasurer and Secretary* |

---