# EDGAR Filing Document

**Accession Number:** 0001827506
**File Stem:** 0001104659-25-108172
**Filing Date:** 2025-11
**Character Count:** 2974
**Document Hash:** bad91e16b1ca563c436f1f35d3e98add
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-108172.hdr.sgml**: 20251107

**ACCESSION NUMBER**: 0001104659-25-108172

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251107

**DATE AS OF CHANGE**: 20251107

**EFFECTIVENESS DATE**: 20251107

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Tourmaline Bio, Inc.
- **CENTRAL INDEX KEY:** 0001827506
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 15-12G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40384
- **FILM NUMBER:** 251460668

**BUSINESS ADDRESS:**
- **STREET 1:** 27 WEST 24TH STREET
- **STREET 2:** SUITE 702
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010
- **BUSINESS PHONE:** 646-481-9832

**MAIL ADDRESS:**
- **STREET 1:** 27 WEST 24TH STREET
- **STREET 2:** SUITE 702
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Talaris Therapeutics, Inc.
- **DATE OF NAME CHANGE:** 20201007

**UNITED STATES<br> SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

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**FORM 15**

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**CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION<br> UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934<br> OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d)<br> OF THE SECURITIES EXCHANGE ACT OF 1934**

**Commission File Number: 001-40384**

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**Tourmaline Bio, Inc.**

**(Exact name of registrant as specified in its charter)**

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**27 West 24th Street, Suite 702**

**New York, NY 10010**

**(646) 481-9832<br> (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)**

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

**None<br> (Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains)**

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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:

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| | |
|:---|:---|
| 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) | ◻ |

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

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

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| | | | |
|:---|:---|:---|:---|
|  | TOURMALINE BIO, INC. | TOURMALINE BIO, INC. | TOURMALINE BIO, INC. |
| Date: November 7, 2025 | By: | /s/ Jaime Huertas | /s/ Jaime Huertas |
|  |  | Name: | Jaime Huertas |
|  |  | Title: | Secretary |

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