Pfizer License Agreement	3 Months Ended
Mar. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Pfizer License Agreement	Pfizer License Agreement On May 3, 2022 (the “Effective Date”), the Company entered into a License Agreement (the “Pfizer License Agreement”) with Pfizer Inc. (“Pfizer”), pursuant to which the Company obtained an exclusive, sublicensable, royalty-bearing, worldwide right to use and license under certain know-how for the development, commercialization and manufacture of PF-04236921 (the “Compound”, now known as pacibekitug) and any pharmaceutical or biopharmaceutical product incorporating the Compound (the “Product”), for the treatment, diagnosis, or prevention of any and all diseases, disorders, illnesses and conditions in humans and animals. In consideration for the license and other rights the Company received under the Pfizer License Agreement, the Company paid Pfizer an upfront payment of $5.0 million and issued to Pfizer 7,125,000 Series A preferred units of Tourmaline Bio, LLC (the predecessor of Legacy Tourmaline), which subsequently converted to 7,125,000 shares of Series A convertible preferred stock of Legacy Tourmaline, representing a 15% interest in the Company on a fully-diluted basis at the time of issuance. The units were issued for $1.00 per unit, representing a total value of $7.1 million. In accordance with ASC Topic 805, Business Combinations, the Pfizer License Agreement was accounted for as an asset acquisition as the licensed compound represented substantially all of the fair value of the gross assets acquired. On the Effective Date, the licensed compound had not yet received regulatory approval and did not have an alternative use. As additional consideration for the license, the Company is obligated to pay Pfizer up to $128.0 million upon the achievement of specific development and regulatory milestones. The Company is also obligated to pay Pfizer up to $525.0 million upon the first achievement of specific sales milestones. The Company is also obligated to pay Pfizer a marginal royalty rate in the low double digits (less than 15%), subject to specified royalty reductions. The royalty term, on a Product-by-Product and country-by-country basis, begins on the first commercial sale of such Product and expires upon the later of twelve years following the date of the first commercial sale or the expiration of regulatory exclusivity protecting such Product. In the event the Company completes a Significant Transaction (as defined in the Pfizer License Agreement), the Company will be obligated to pay Pfizer a one-time payment in the low-eight digits (up to $20.0 million); the amount of such payment is based on the timing of the transaction. As of March 31, 2025, the Company does not owe any milestone or royalties under the Pfizer License Agreement and no such milestones or royalties have been paid to date.

On May 3, 2022 (the “Effective Date”), the Company entered into a License Agreement (the “Pfizer License Agreement”) with Pfizer Inc. (“Pfizer”), pursuant to which the Company obtained an exclusive, sublicensable, royalty-bearing, worldwide right to use and license under certain know-how for the development, commercialization and manufacture of PF-04236921 (the “Compound”, now known as pacibekitug) and any pharmaceutical or biopharmaceutical product incorporating the Compound (the “Product”), for the treatment, diagnosis, or prevention of any and all diseases, disorders, illnesses and conditions in humans and animals. In consideration for the license and other rights the Company received under the Pfizer License Agreement, the Company paid Pfizer an upfront payment of $5.0 million and issued to Pfizer 7,125,000 Series A preferred units of Tourmaline Bio, LLC (the predecessor of Legacy Tourmaline), which subsequently converted to 7,125,000 shares of Series A convertible preferred stock of Legacy Tourmaline, representing a 15% interest in the Company on a fully-diluted basis at the time of issuance. The units were issued for $1.00 per unit, representing a total value of $7.1 million. In accordance with ASC Topic 805, Business Combinations, the Pfizer License Agreement was accounted for as an asset acquisition as the licensed compound represented substantially all of the fair value of the gross assets acquired. On the Effective Date, the licensed compound had not yet received regulatory approval and did not have an alternative use.

million upon the first achievement of specific sales milestones. The Company is also obligated to pay Pfizer a marginal royalty rate in the low double digits (less than 15%), subject to specified royalty reductions. The royalty term, on a Product-by-Product and country-by-country basis, begins on the first commercial sale of such Product and expires upon the later of twelve years following the date of the first commercial sale or the expiration of regulatory exclusivity protecting such Product. In the event the Company completes a Significant Transaction (as defined in the Pfizer License Agreement), the Company will be obligated to pay Pfizer a one-time payment in the low-eight digits (up to $20.0 million); the amount of such payment is based on the timing of the transaction.