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

Rhea-AI Filing Summary

Tourmaline Bio (TRML) CEO and director reported insider transactions linked to the company’s acquisition by Novartis AG. On October 28, 2025, shares were tendered for $48.00 per share in cash under the Merger Agreement.

All outstanding stock options held by the insider were canceled at closing and converted into a cash right equal to the Merger Consideration minus the exercise price, multiplied by the underlying shares. This included options with exercise prices of $7.90 (covering 503,478 shares), $9.46 (covering 254,207 shares), and $15.54 (covering 226,000 shares). The filing indicates no derivative securities remained afterward.

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^*

Kulkarni Sandeep Chidambar

(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
X	Officer (give title below)		Other (specify below)
	CEO

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
Common Stock	10/28/2025		U(1)		724,664	D	(2)	30,387	D
Common Stock	10/28/2025		D(1)		30,387	D	(3)	0	D
Common Stock	10/28/2025		U(1)		7,000	D	(2)	0	I	By Gilead Capital, LP(4)

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)	$7.9	10/28/2025		D(1)			503,478	(5)	(5)	Common Stock	503,478	(5)	0	D
Employee Stock Option (Right to Buy)	$9.46	10/28/2025		D(1)			254,207	(5)	(5)	Common Stock	254,207	(5)	0	D
Employee Stock Option (Right to Buy)	$15.54	10/28/2025		D(1)			226,000	(5)	(5)	Common Stock	226,000	(5)	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 Share was tendered in exchange for $48.00 in cash per Share.

3. Pursuant to the terms of the Merger Agreement, each restricted Share outstanding and subject to the Issuer's repurchase right as of immediately prior to the Effective Time became fully vested effective as of immediately prior to the Effective Time, and, by virtue of the merger and net of any applicable withholding taxes, was treated as a Share for all purposes under the terms of the Merger Agreement.

4. These shares are held by Gilead Capital, LP ("Gilead"). The Reporting Person's spouse is a partner of Gilead and shares voting and investment power with respect to the shares held by Gilead, and therefore the Reporting Person may be deemed an indirect beneficial owner of these shares. This report is not an admission that the Reporting Person is an indirect beneficial owner of these shares for purposes of Section 16 or for any other purpose.

5. 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’s CEO report in this Form 4?

Transactions tied to the merger with Novartis AG, including tendering shares for $48.00 per share and canceling options for cash per the agreement.

What was the cash consideration per Tourmaline Bio share?

Each share was exchanged for $48.00 in cash pursuant to the Merger Agreement.

When did the tender offer close?

On October 28, 2025, when shares were accepted for payment under the merger terms.

How were the CEO’s stock options treated?

They were canceled and converted into a cash right equal to $48.00 minus the exercise price times the underlying shares.

Which option tranches were affected and at what exercise prices?

Options with exercise prices of $7.90 (503,478 shares), $9.46 (254,207 shares), and $15.54 (226,000 shares) were canceled for cash.

What roles does the reporting person hold at TRML?

The reporting person is a Director and CEO of Tourmaline Bio.