Document

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

SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1 – Exit Filing)*

TOURMALINE BIO, INC.
(Name of Issuer)

Common Stock, par value $0.0001 per share
(Title of Class of Securities)

89157D 105
(CUSIP Number)

January 29, 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 disclosures provided in a prior cover page.

The information required on 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).

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CUSIP No. 89157D 105






1.	Names of Reporting Persons. PFIZER INC.
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ☐ (b) ☐
3.	SEC Use Only
4.	Citizenship or Place of Organization: Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:		5.	Sole Voting Power: 1,272,214 shares of common stock, $0.0001 par value per share (“Common Stock”)
		6.	Shared Voting Power: -0-
		7.	Sole Dispositive Power: 1,272,214 shares of Common Stock
		8.	Shared Dispositive Power: -0-
9.	Aggregate Amount Beneficially Owned by Reporting Person: 1,272,214 shares of Common Stock are beneficially owned by Pfizer Inc.
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)
11.	Percent of Class Represented by Amount in Row (9): 4.96%(1)
12.	Type of Reporting Person (See Instructions): CO

(1) This percentage is calculated based on 25,645,262 shares of Common Stock outstanding, as disclosed by the Issuer in its prospectus supplement dated January 25, 2024 and filed with the Securities and Exchange Commission on January 26, 2024 pursuant to Rule 424(b)(5) under the Securities Act of 1933, as amended.

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CUSIP No. 89157D 105

ITEM 1.
(A) NAME OF ISSUER:

Tourmaline Bio, Inc.

(B) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICE:

27 West 24th Street, Suite 702, New York, NY 10010

ITEM 2.
(A) NAME OF PERSON FILING:

Pfizer Inc.

(B) ADDRESS OR PRINCIPAL BUSINESS OFFICE OR IF NONE, RESIDENCE:

66 Hudson Boulevard East, New York, NY 10001-2192

Delaware, U.S.A.

(D) TITLE OF CLASS OF SECURITIES:

Common stock, $0.0001 par value per share

(E) CUSIP NUMBER:

89157D 105

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.
(a) ☐ Broker or dealer registered under section 15 of the Act (15 U.S.C. 78os).
(b) ☐ Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
(c) ☐ Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
(d) ☐ Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).
(e) ☐ An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E).
(f ) ☐ An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F).

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CUSIP No. 89157D 105

(g) ☐ A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G).
(h) ☐ A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813).
(i) ☐ A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3).
(j) ☐ A non-US institution, in accordance with §240.13d-1(b)(1)(ii)(J);
(k) ☐ Group, in accordance with §230.405 240.13d-1(b)(1)(ii)(K).

If filing as a non-US institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution: Not applicable.

ITEM 4. OWNERSHIP.

See rows 5 through 11 of the cover page.

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 5 percent of the class of securities, check the following |X|.

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
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 that purpose or effect, other than activities solely in connection with a nomination under §240.14a-11.

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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: March 15, 2024

PFIZER INC.

By: /s/ Susan Grant
Name: Susan Grant
Title: Assistant Secretary

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