[Form 4] Tourmaline Bio, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Tourmaline Bio (TRML) reported a director’s Form 4 reflecting option dispositions tied to the company’s acquisition by Novartis AG. On October 28, 2025, a cash tender offer closed at $48.00 per share, after which unexercised options were automatically canceled and converted into cash equal to the merger price minus the exercise price, multiplied by the underlying shares.

The filing lists three employee stock option grants canceled for cash settlement: 20,000 shares at $18.55, 15,000 shares at $13.91, and 16,800 shares at $18.73. Following these transactions, the reporting person held 0 derivative securities. This reflects mechanical settlement terms under the merger agreement.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

SIEGALL CLAY B

(Last) (First) (Middle)

C/O TOURMALINE BIO, INC.

27 WEST 24TH STREET, SUITE 702

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Tourmaline Bio, Inc. [ TRML ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/28/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	$18.55	10/28/2025		D(1)			20,000	(2)	(2)	Common Stock	20,000	(2)	0	D
Employee Stock Option (Right to Buy)	$13.91	10/28/2025		D(1)			15,000	(2)	(2)	Common Stock	15,000	(2)	0	D
Employee Stock Option (Right to Buy)	$18.73	10/28/2025		D(1)			16,800	(2)	(2)	Common Stock	16,800	(2)	0	D

Explanation of Responses:

1. This Form 4 reports securities disposed pursuant to that certain Agreement and Plan of Merger (the "Merger Agreement"), dated as of September 8, 2025, by and among Issuer, Novartis AG, a company limited by shares (Aktiengesellschaft) incorporated under the laws of Switzerland ("Parent"), and Torino Merger Sub Inc., a Delaware corporation and indirect wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the Merger Agreement, on October 28, 2025, Merger Sub completed a cash tender offer to acquire all of the shares of common stock of the Issuer, par value $0.0001 (the "Shares"), issued and outstanding immediately prior to the effective time of the merger (the "Effective Time"), in exchange for $48.00 in cash per Share, subject to any applicable withholding of taxes (the "Merger Consideration").

2. Pursuant to the terms of the Merger Agreement, each stock option that was outstanding and unexercised immediately prior to the Effective Time was automatically canceled and terminated and converted into the right to receive an amount in cash, without interest, equal to the product of (i) the amount by which the Merger Consideration exceeds the applicable exercise price per Share of such option and (ii) the aggregate number of Shares issuable upon exercise of such option or portion thereof, subject to any applicable withholding of taxes.

	/s/ Brad Middlekauff, Attorney-in-Fact	10/28/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did TRML disclose in this Form 4?

A director reported automatic cancellation of stock options upon closing of a merger, with cash paid based on the $48.00 per-share merger price.

What was the merger consideration for Tourmaline Bio (TRML)?

Common stock was acquired for $48.00 in cash per share, subject to applicable withholding taxes.

When did the transaction occur?

The tender offer closed and the option treatment occurred on October 28, 2025.

How were the options treated at closing?

Each unexercised option was canceled and converted into a cash payment equal to ($48.00 minus the exercise price) times the number of shares.

Which option grants were impacted?

Three grants: 20,000 at $18.55, 15,000 at $13.91, and 16,800 at $18.73 exercise prices.

What is the reporting person’s post-transaction holdings?

The filing shows 0 derivative securities beneficially owned after the reported transactions.

What was the reporting person’s relationship to TRML?

The individual was a Director of Tourmaline Bio.