W. Bradford Middlekauff - Oct 19, 2023 Form 4 Insider Report for Tourmaline Bio, Inc. (TALS)

Role: CBO, GC and Secretary
Signature: /s/ W. Bradford Middlekauff
Stock symbol: TALS
Transactions as of: Oct 19, 2023
Transactions value $: $0
Form type: 4
Date filed: 10/23/2023, 08:29 PM

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	TALS	Common Stock	Award		+69.2K			69.2K	Oct 19, 2023	Direct	F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	TALS	Employee Stock Option (Right to Buy)	Award		+125K			125K	Oct 19, 2023	Common Stock	125K	$7.90	Direct	F3, F4, F5
transaction	TALS	Employee Stock Option (Right to Buy)	Award	$0	+46.8K		$0.00	46.8K	Oct 23, 2023	Common Stock	46.8K	$9.46	Direct	F6

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	32,839 of these shares are subject to a repurchase option in favor of the Issuer in the event that the Reporting Person's continuous service is terminated. Such repurchase option shall lapse in equal monthly installments until such shares are fully vested on June 1, 2026.
F2	Received in exchange for 867,500 shares of common stock of Tourmaline Bio, Inc. ("Tourmaline") pursuant to an Agreement and Plan of Merger dated as of June 22, 2023 (the "Merger Agreement") by and among Tourmaline, the Issuer and Terrain Merger Sub, Inc., a wholly owned subsidiary of the Issuer ("Merger Sub"). Under the terms of the Merger Agreement, on October 19, 2023, Merger Sub merged with and into Tourmaline (the "Merger"), with Tourmaline surviving the Merger as a wholly owned subsidiary of the Issuer. Upon the closing of the Merger, each share of Tourmaline common stock was converted into the right to receive 0.07977 of a share of the Issuer's common stock, after giving effect to a reverse stock split of the Issuer's common stock of 10-for-1. Subsequent to the Merger, the name of the Issuer was changed from Talaris Therapeutics, Inc. to Tourmaline Bio, Inc.
F3	Upon the closing of the Merger, each outstanding option to purchase shares of Tourmaline common stock was assumed by the Issuer and converted into an option to purchase the Issuer's common stock, on the same terms and conditions as were applicable to such Tourmaline stock option prior to the Merger, as adjusted for the exchange ratio and the reverse stock split.
F4	The shares subject to the option vest as to 25% of the shares on June 14, 2024 with the remainder vesting in the following 36 equal monthly installments, subject to the Reporting Person's continued service on each such vesting date.
F5	Received in exchange for a stock option to acquire 1,566,900 shares of Tourmaline common stock pursuant to the Merger Agreement.
F6	The shares subject to the option vest as to 25% of the shares on October 23, 2024 with the remainder vesting in the following 36 equal monthly installments, subject to the Reporting Person's continued service on each such vesting date.