Organization and description of business	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and description of business	1. Organization and description of business Galera Therapeutics, Inc. (the Company, or Galera) is a biopharmaceutical company that historically was focused on developing a portfolio of small molecule dismutase (SOD) mimetics to improve radiotherapy in cancer, primarily by reducing one of the most common side effects of radiotherapy, severe oral mucositis (SOM). The Company sold its assets related to avasopasem and rucosopasem and all other dismutase mimetics assets to Biossil, Inc. (Biossil), a privately-held company based in Toronto, Canada, in October 2025. Galera received consideration from Biossil in the form of an upfront payment of $3.5 million and is eligible to receive further payments upon the achievement of future regulatory and commercial milestones and to receive contingent value rights of up to $105.0 million in the aggregate. In addition, Biossil assumed all rights and obligations associated with the Company’s royalty purchase obligation (Note 7), resulting in a gain on sale of assets of $3.5 million and a gain on extinguishment of debt of $151.0 million related to the extinguishment of the royalty purchase liability that was assumed by Biossil. Galera’s clinical portfolio now is comprised of a pan-inhibitor of nitric oxide synthase (NOS) that was acquired in December 2024 through the acquisition of Nova Pharmaceuticals, Inc. (Nova). Galera’s lead program is now an investigator-sponsored Phase 1/2 trial of the pan-NOS inhibitor in combination with nab-paclitaxel and alpelisib for MpBC, which is being conducted at Methodist Hospital in Houston, Texas (Houston Methodist) with funding by a grant from the National Institutes of Health. In April 2026 the Company entered into an Agreement and Plan of Merger (the Merger Agreement) with Obsidian Therapeutics, Inc. (Obsidian), a privately-held company based in Cambridge, Massachusetts (Note 12). Pursuant to the Merger Agreement, and upon the terms and subject to the satisfaction or waiver of the conditions described therein, Galera will be merged with and into a merger subsidiary of a newly formed parent company, Gazelle Parent, Inc. (Parent), with Galera surviving as a wholly owned subsidiary of Parent, and Obsidian will be merged with and into a separate merger subsidiary of Parent, with Obsidian surviving as a wholly owned subsidiary of Parent. Upon completion of the transaction, the combined company is expected to operate under the name Obsidian Therapeutics, Inc. and focus primarily on advancing Obsidian’s pipeline of engineered tumor infiltrating lymphocyte (TIL) cell therapies for the treatment of patients with solid tumors, including its lead product candidate, OBX-115, while continuing to support Galera’s pipeline. Closing of the planned merger (the Obsidian Merger) is subject to certain closing conditions, including the effectiveness of a registration statement on Form S-4 and approval by the stockholders of both companies. Also in April 2026, Galera entered into a securities purchase agreement with certain investors, pursuant to which Galera has agreed to sell, and such investors have agreed to purchase, shares of Galera’s Series C Non-Voting Convertible Preferred Stock, $0.001 par value, for an aggregate purchase price of approximately $350.0 million (less any proceeds received by Obsidian in connection with certain interim permitted financings), immediately prior to the closing of the Obsidian Merger (a Private Investment in Public Equity, or PIPE). The concurrent closing of the PIPE is conditioned upon the satisfaction or waiver of each of the conditions to the closing of the Obsidian Merger, other than those conditions which, by their nature, are to be satisfied at the closing of the transactions contemplated by the Merger Agreement, as well as certain other conditions. The percentage of the combined company that pre-closing Galera security holders will own as of the closing of the Obsidian Merger is subject to adjustment based on the valuation of Galera immediately prior to the closing. Furthermore, each holder of Galera common stock of record as of the consummation of the PIPE will be entitled to (i) one contingent value right (CVR) for each share of Galera common stock held by such holder, representing the right to receive a pro rata portion of 80% of any potential future net proceeds received by Parent or its affiliates from the development, commercialization, licensing, sale or other disposition of Galera’s product candidate, tilarginine, or related intellectual property during the five years following the closing of the Obsidian Merger and (ii) one CVR for each share of Galera common stock held by such holder, representing the right to receive a pro rata portion of 95% of any potential future net proceeds received by Parent or its affiliates from the Asset Purchase and Sale Agreement with Biossil during the ten years following the closing of the Obsidian Merger. Liquidity The Company follows the provisions of the Financial Accounting Standards Board (FASB), Accounting Standards Codification (ASC) Topic 205-40, Presentation of Financial Statements—Going Concern, which requires management to assess the Company’s ability to continue as a going concern for one year after the date the consolidated financial statements are issued. The Company has incurred recurring losses and negative cash flows from operations since inception and has an accumulated deficit of $308.9 million as of March 31, 2026. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidate currently in development. Additionally, the Company has incurred significant expenses in connection with the planned Obsidian Merger, including expenses for the Merger Agreement and the registration statement on Form S-4. As a result of these conditions, it expects its existing cash and cash equivalents as of March 31, 2026 will not enable the Company to fund its operating expenses and capital expenditure requirements for more than one year after the date these consolidated financial statements are issued, and therefore management has concluded that substantial doubt exists about the Company's ability to continue as a going concern. Management’s plans to mitigate this risk involve a strategic transaction through the Obsidian Merger. Management’s plans may also include the deferral of certain operating expenses unless and until additional capital is received. However, there can be no assurance that the Company will be successful in consummating the Obsidian Merger or deferring certain operating expenses. The Company's ability to continue operations is dependent on consummating the Obsidian Merger and the related financing transactions on a timely basis. If the Obsidian Merger is not completed, the Company may be required to pursue other strategic alternatives, which could include raising additional capital on unfavorable terms, significantly reducing or discontinuing operations, or pursuing a voluntary dissolution. The consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the continuity of operations, the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The consolidated financial statements do not include any adjustments to the carrying amounts and classification of assets, liabilities, and reported expenses that may be necessary if the Company were unable to continue as a going concern. In December 2024, the Company completed a private placement with a group of investors led by Ikarian Capital, LLC (Ikarian). The Company issued 21,070,220 shares of common stock plus pre-funded warrants exercisable for 23,041,040 shares of common stock at an offering price of $0.065 per share or pre-funded warrant. The Company received net proceeds of approximately $2.9 million after deducting issuance costs of approximately $27,000, of which $0.6 million was received in January 2025. The pre-funded warrants have an exercise price of $0.001 per share, are exercisable immediately following their issuance and never expire. The Company does not currently have sufficient cash to adequately fund the development of its product candidate. In order to continue research and development, the Company will need to raise additional financing to fund its operations, which could be through equity or debt financing or through strategic transactions such as the Obsidian Merger. Future capital requirements will depend on what, if any, strategic alternatives are available to the Company, which may include pursuit of a strategic transaction, a voluntary dissolution, or the continued operation of product development.

Galera Therapeutics, Inc. (the Company, or Galera) is a biopharmaceutical company that historically was focused on developing a portfolio of small molecule dismutase (SOD) mimetics to improve radiotherapy in cancer, primarily by reducing one of the most common side effects of radiotherapy, severe oral mucositis (SOM). The Company sold its assets related to avasopasem and rucosopasem and all other dismutase mimetics assets to Biossil, Inc. (Biossil), a privately-held company based in Toronto, Canada, in October 2025. Galera received consideration from Biossil in the form of an upfront payment of $3.5 million and is eligible to receive further payments upon the achievement of future regulatory and commercial milestones and to receive contingent value rights of up to $105.0 million in the aggregate. In addition, Biossil assumed all rights and obligations associated with the Company’s royalty purchase obligation (Note 7), resulting in a gain on sale of assets of $3.5 million and a gain on extinguishment of debt of $151.0 million related to the extinguishment of the royalty purchase liability that was assumed by Biossil.

Galera’s clinical portfolio now is comprised of a pan-inhibitor of nitric oxide synthase (NOS) that was acquired in December 2024 through the acquisition of Nova Pharmaceuticals, Inc. (Nova). Galera’s lead program is now an investigator-sponsored Phase 1/2 trial of the pan-NOS inhibitor in combination with nab-paclitaxel and alpelisib for MpBC, which is being conducted at Methodist Hospital in Houston, Texas (Houston Methodist) with funding by a grant from the National Institutes of Health.

In April 2026 the Company entered into an Agreement and Plan of Merger (the Merger Agreement) with Obsidian Therapeutics, Inc. (Obsidian), a privately-held company based in Cambridge, Massachusetts (Note 12). Pursuant to the Merger Agreement, and upon the terms and subject to the satisfaction or waiver of the conditions described therein, Galera will be merged with and into a merger subsidiary of a newly formed parent company, Gazelle Parent, Inc. (Parent), with Galera surviving as a wholly owned subsidiary of Parent, and Obsidian will be merged with and into a separate merger subsidiary of Parent, with Obsidian surviving as a wholly owned subsidiary of Parent. Upon completion of the transaction, the combined company is expected to operate under the name Obsidian Therapeutics, Inc. and focus primarily on advancing Obsidian’s pipeline of engineered tumor infiltrating lymphocyte (TIL) cell therapies for the treatment of patients with solid tumors, including its lead product candidate, OBX-115, while continuing to support Galera’s pipeline. Closing of the planned merger (the Obsidian Merger) is subject to certain closing conditions, including the effectiveness of a registration statement on Form S-4 and approval by the stockholders of both companies.

Also in April 2026, Galera entered into a securities purchase agreement with certain investors, pursuant to which Galera has agreed to sell, and such investors have agreed to purchase, shares of Galera’s Series C Non-Voting Convertible Preferred Stock, $0.001 par value, for an aggregate purchase price of approximately $350.0 million (less any proceeds received by Obsidian in connection with certain interim permitted financings), immediately prior to the closing of the Obsidian Merger (a Private Investment in Public Equity, or PIPE). The concurrent closing of the PIPE is conditioned upon the satisfaction or waiver of each of the conditions to the closing of the Obsidian Merger, other than those conditions which, by their nature, are to be satisfied at the closing of the transactions contemplated by the Merger Agreement, as well as certain other conditions.

The percentage of the combined company that pre-closing Galera security holders will own as of the closing of the Obsidian Merger is subject to adjustment based on the valuation of Galera immediately prior to the closing. Furthermore, each holder of Galera common stock of record as of the consummation of the PIPE will be entitled to (i) one contingent value right (CVR) for each share of Galera common stock held by such holder, representing the right to receive a pro rata portion of 80% of any potential future net proceeds received by Parent or its affiliates from the development, commercialization, licensing, sale or other disposition of Galera’s product candidate, tilarginine, or related intellectual property during the five years following the closing of the Obsidian Merger and (ii) one CVR for each share of Galera common stock held by such holder, representing the right to receive a pro rata portion of 95% of any potential future net proceeds received by Parent or its affiliates from the Asset Purchase and Sale Agreement with Biossil during the ten years following the closing of the Obsidian Merger.

Liquidity

The Company follows the provisions of the Financial Accounting Standards Board (FASB), Accounting Standards Codification (ASC) Topic 205-40, Presentation of Financial Statements—Going Concern, which requires management to assess the Company’s ability to continue as a going concern for one year after the date the consolidated financial statements are issued.

The Company has incurred recurring losses and negative cash flows from operations since inception and has an accumulated deficit of $308.9 million as of March 31, 2026. The Company anticipates incurring additional losses until such time, if

ever, that it can generate significant sales of its product candidate currently in development. Additionally, the Company has incurred significant expenses in connection with the planned Obsidian Merger, including expenses for the Merger Agreement and the registration statement on Form S-4. As a result of these conditions, it expects its existing cash and cash equivalents as of March 31, 2026 will not enable the Company to fund its operating expenses and capital expenditure requirements for more than one year after the date these consolidated financial statements are issued, and therefore management has concluded that substantial doubt exists about the Company's ability to continue as a going concern.

Management’s plans to mitigate this risk involve a strategic transaction through the Obsidian Merger. Management’s plans may also include the deferral of certain operating expenses unless and until additional capital is received. However, there can be no assurance that the Company will be successful in consummating the Obsidian Merger or deferring certain operating expenses. The Company's ability to continue operations is dependent on consummating the Obsidian Merger and the related financing transactions on a timely basis. If the Obsidian Merger is not completed, the Company may be required to pursue other strategic alternatives, which could include raising additional capital on unfavorable terms, significantly reducing or discontinuing operations, or pursuing a voluntary dissolution.

The consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the continuity of operations, the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The consolidated financial statements do not include any adjustments to the carrying amounts and classification of assets, liabilities, and reported expenses that may be necessary if the Company were unable to continue as a going concern.

In December 2024, the Company completed a private placement with a group of investors led by Ikarian Capital, LLC (Ikarian). The Company issued 21,070,220 shares of common stock plus pre-funded warrants exercisable for 23,041,040 shares of common stock at an offering price of $0.065 per share or pre-funded warrant. The Company received net proceeds of approximately $2.9 million after deducting issuance costs of approximately $27,000, of which $0.6 million was received in January 2025. The pre-funded warrants have an exercise price of $0.001 per share, are exercisable immediately following their issuance and never expire.

The Company does not currently have sufficient cash to adequately fund the development of its product candidate. In order to continue research and development, the Company will need to raise additional financing to fund its operations, which could be through equity or debt financing or through strategic transactions such as the Obsidian Merger. Future capital requirements will depend on what, if any, strategic alternatives are available to the Company, which may include pursuit of a strategic transaction, a voluntary dissolution, or the continued operation of product development.