Organization and Basis of Presentation	12 Months Ended
Dec. 31, 2022
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 late clinical stage biotechnology 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 and commercializing viral immunotherapies 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. The Company has established two clinical stage viral immunotherapy platforms and its two product candidates, CAN-2409 and CAN-3110, are in clinical trials for a number of tumor types. In addition, the Company recently announced a collaboration with the University of Pennsylvania (Penn) to study the impact of novel viral immunotherapies based on Candel's propriety enLIGHTEN™ Discovery Platform to strengthen the effects of Penn's investigational CAR-T cell therapies in solid tumor models. The Company is subject to risks and uncertainties common to early-stage 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. 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 has incurred recurring losses since its inception, including a net loss of $18.8 million and $36.1 million for the years ended December 31, 2022, and 2021, respectively. In addition, as of December 31, 2022, the Company had an accumulated deficit of $99.1 million. The Company expects to continue to generate operating losses for the foreseeable future. On July 29, 2021, the Company completed its initial public offering of common stock (the IPO) at which time the Company issued 9,000,000 shares of its common stock at a price to the public of $8.00 per share, and on August 13, 2021, the Company issued an additional 887,994 shares of common stock at $8.00 per share as a partial exercise of the underwriters’ option to purchase additional shares, resulting in net proceeds to the Company of $71.3 million, after deducting underwriting discounts and commissions and offering expenses. Upon closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into 7,066,398 shares of common stock. On August 5, 2022, the Company filed a shelf registration statement on Form S-3 (the Shelf) with the SEC, which covers the offering, issuance, and sale by us of up to an aggregate of $200.0 million of our common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. We simultaneously entered into a sales agreement with Jefferies LLC, as sales agent, to provide for the issuance and sale by us of up to $75.0 million of our common stock from time to time in “at-the-market” offerings under the Shelf (the ATM Program). The Shelf was declared effective by the SEC on August 12, 2022. As of the date hereof, no sales have been made pursuant to the ATM Program. 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 date that these consolidated financial statements were available to be issued. Accordingly, the consolidated financial statements have been prepared on a basis that assumes the Company continues as a going concern and contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Organization and Basis of Presentation

12 Months Ended

Dec. 31, 2022

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 late clinical stage biotechnology 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 and commercializing viral immunotherapies 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. The Company has established two clinical stage viral immunotherapy platforms and its two product candidates, CAN-2409 and CAN-3110, are in clinical trials for a number of tumor types. In addition, the Company recently announced a collaboration with the University of Pennsylvania (Penn) to study the impact of novel viral immunotherapies based on Candel's propriety enLIGHTEN™ Discovery Platform to strengthen the effects of Penn's investigational CAR-T cell therapies in solid tumor models.

The Company is subject to risks and uncertainties common to early-stage 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.

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 has incurred recurring losses since its inception, including a net loss of $18.8 million and $36.1 million for the years ended December 31, 2022, and 2021, respectively. In addition, as of December 31, 2022, the Company had an accumulated deficit of $99.1 million. The Company expects to continue to generate operating losses for the foreseeable future.

On July 29, 2021, the Company completed its initial public offering of common stock (the IPO) at which time the Company issued 9,000,000 shares of its common stock at a price to the public of $8.00 per share, and on August 13, 2021, the Company issued an additional 887,994 shares of common stock at $8.00 per share as a partial exercise of the underwriters’ option to purchase additional shares, resulting in net proceeds to the Company of $71.3 million, after deducting underwriting discounts and commissions and offering expenses. Upon closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into 7,066,398 shares of common stock.

On August 5, 2022, the Company filed a shelf registration statement on Form S-3 (the Shelf) with the SEC, which covers the offering, issuance, and sale by us of up to an aggregate of $200.0 million of our common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. We simultaneously entered into a sales agreement with Jefferies LLC, as sales agent, to provide for the issuance and sale by us of up to $75.0 million of our common stock from time to time in “at-the-market” offerings under the Shelf (the ATM Program). The Shelf was declared effective by the SEC on August 12, 2022. As of the date hereof, no sales have been made pursuant to the ATM Program.

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 date that these consolidated financial statements were available to be issued.

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