Organization and Basis of Presentation	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Candel Therapeutics, Inc., formerly known as Advantagene, Inc. (the Company), is a clinical stage biopharmaceutical company that was incorporated in Delaware in June 2003. On November 30, 2020, the Company changed its name to Candel Therapeutics, Inc. The Company is focused on developing off-the-shelf viral immunotherapies that elicit an individualized, systemic anti-tumor immune response to help patients fight cancer. The Company’s engineered viruses are designed to induce immunogenic cell death through direct viral-mediated cytotoxicity in cancer cells, thus releasing tumor neo-antigens and creating a pro-inflammatory microenvironment at the site of injection. This is intended to lead to in-situ immunization against the injected tumor and uninjected distant metastases. The Company has established two off-the-shelf viral immunotherapy platforms and its two product candidates, aglatimagene and linoserpaturev, are in clinical trials for a number of tumor types. The Company is subject to risks and uncertainties common to companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. Since inception, the Company has funded its operations primarily with proceeds from the sale of its convertible notes and capital stock and from debt borrowings. The Company had net loss of $8.9 million and net income of $7.4 million for the three months ended March 31, 2026 and 2025, respectively. In addition, as of March 31, 2026, the Company had an accumulated deficit of $239.2 million. The Company expects to continue to generate operating losses and negative cash flows from operations for the foreseeable future. On August 14, 2025, the Company filed a shelf registration statement on Form S-3 (the 2025 Shelf) with the SEC, which covers the offering, issuance, and sale by us of up to an aggregate of $300.0 million of our common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. The Company simultaneously entered into a sales agreement with Jefferies LLC, as sales agent, to provide for the issuance and sale by the Company of up to $50.0 million of our common stock from time to time in “at-the-market” offerings under the 2025 Shelf (the 2025 ATM Program). The 2025 Shelf was declared effective by the SEC on August 22, 2025. As of March 31, 2026 and through May 7, 2026, the Company has not sold any shares of common stock under the 2025 ATM Program. On February 23, 2026, the Company completed a public offering of its common stock (the 2026 Follow-On Offering). The Company issued and sold 18,348,624 shares of common stock at a price to the public of $5.45 per share for aggregate gross proceeds of approximately $100 million. The Company received approximately $93.5 million in net proceeds from the 2026 Follow-On Offering after deducting underwriting discounts and commissions and offering expenses. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurances that additional funding will be available on terms acceptable to the Company, or at all. The Company believes that existing resources will fund planned operations for at least 12 months from the issuance date of these condensed consolidated financial statements. Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and that contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Organization and Basis of Presentation

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Organization and Basis of Presentation

Candel Therapeutics, Inc., formerly known as Advantagene, Inc. (the Company), is a clinical stage biopharmaceutical company that was incorporated in Delaware in June 2003. On November 30, 2020, the Company changed its name to Candel Therapeutics, Inc. The Company is focused on developing off-the-shelf viral immunotherapies that elicit an individualized, systemic anti-tumor immune response to help patients fight cancer. The Company’s engineered viruses are designed to induce immunogenic cell death through direct viral-mediated cytotoxicity in cancer cells, thus releasing tumor neo-antigens and creating a pro-inflammatory microenvironment at the site of injection. This is intended to lead to in-situ immunization against the injected tumor and uninjected distant metastases. The Company has established two off-the-shelf viral immunotherapy platforms and its two product candidates, aglatimagene and linoserpaturev, are in clinical trials for a number of tumor types.

The Company is subject to risks and uncertainties common to companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales.

Since inception, the Company has funded its operations primarily with proceeds from the sale of its convertible notes and capital stock and from debt borrowings. The Company had net loss of $8.9 million and net income of $7.4 million for the three months ended March 31, 2026 and 2025, respectively. In addition, as of March 31, 2026, the Company had an accumulated deficit of $239.2 million. The Company expects to continue to generate operating losses and negative cash flows from operations for the foreseeable future.

On August 14, 2025, the Company filed a shelf registration statement on Form S-3 (the 2025 Shelf) with the SEC, which covers the offering, issuance, and sale by us of up to an aggregate of $300.0 million of our common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. The Company simultaneously entered into a sales agreement with Jefferies LLC, as sales agent, to provide for the issuance and sale by the Company of up to $50.0 million of our common stock from time to time in “at-the-market” offerings under the 2025 Shelf (the 2025 ATM Program). The 2025 Shelf was declared effective by the SEC on August 22, 2025. As of March 31, 2026 and through May 7, 2026, the Company has not sold any shares of common stock under the 2025 ATM Program.

On February 23, 2026, the Company completed a public offering of its common stock (the 2026 Follow-On Offering). The Company issued and sold 18,348,624 shares of common stock at a price to the public of $5.45 per share for aggregate gross proceeds of approximately $100 million. The Company received approximately $93.5 million in net proceeds from the 2026 Follow-On Offering after deducting underwriting discounts and commissions and offering expenses.

The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurances that additional funding will be available on terms acceptable to the Company, or at all. The Company believes that existing resources will fund planned operations for at least 12 months from the issuance date of these condensed consolidated financial statements.

Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and that contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.