Organization and Nature of Business	9 Months Ended
Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business	1. Organization and Nature of the Business Adicet Bio, Inc. (formerly resTORbio, Inc. (resTORbio), together with its subsidiaries, the Company) is a clinical stage biotechnology company discovering and developing allogeneic gamma delta T cell therapies for cancer. The Company is advancing a pipeline of “off-the-shelf” gamma delta T cells, engineered with chimeric antigen receptors (CARs) to enhance selective tumor targeting and facilitate innate and adaptive anti-tumor immune response for durable activity in patients. The Company's approach to activate, engineer, and manufacture allogeneic gamma delta T cell product candidates derived from the peripheral blood cells of unrelated donors allows it to generate new product candidates in a rapid and cost-efficient manner. Adicet Bio, Inc. (when referred to prior to the merger, Former Adicet) was incorporated in November 2014 in Delaware. On September 15, 2020, Former Adicet completed a merger (Merger) with resTORbio, pursuant to which Former Adicet merged with a wholly owned subsidiary of resTORbio in an all-stock transaction with Former Adicet surviving as a wholly owned subsidiary of resTORbio and changing its name to “Adicet Therapeutics, Inc.” (Adicet Therapeutics). In connection with the Merger, the Company changed its name from “resTORbio, Inc.” to “Adicet Bio, Inc.” The Company’s principal executive offices are located in Boston, Massachusetts. The Company also has offices in Redwood City, California. Adicet Bio Israel Ltd. (formerly Applied Immune Technologies Ltd.) (Adicet Israel) is a wholly owned subsidiary of the Company and is located in Haifa, Israel. Adicet Israel was founded in 2006. During 2019, the Company consolidated its operations, including research and development activities, in the United States and as a result, substantially reduced its operations in Israel. Liquidity The Company has incurred significant net operating losses and negative cash flows from operations and has an accumulated deficit of $351.3 million as of September 30, 2023. The Company has historically financed its operations primarily through a collaboration and licensing arrangement, public and private placements of equity securities and debt, and cash received in the Merger with resTORbio. To date, none of the Company’s product candidates have been approved for sale and therefore the Company has not generated any revenue from product sales. Management expects operating losses and negative cash flows to continue for the foreseeable future, until such time, if ever, that it can generate significant sales of its product candidates currently in development. On March 12, 2021, the Company entered into a Capital On Demand™ Sales Agreement (the Sales Agreement) with JonesTrading Institutional Services LLC, as sales agent, to provide for the offering, issuance and sale of up to an aggregate amount of $75.0 million of shares of common stock from time to time in “at-the-market” (ATM) offerings under a registration statement on Form S-3 (File No. 333-254193) (2021 Shelf Registration Statement) filed with the U.S. Securities and Exchange Commission (the SEC), which was declared effective on March 30, 2021. In August 2022, pursuant to the Sales Agreement and subject to the limitations thereof, the Company sold an aggregate of 2,611,723 shares of common stock at $17.23 per share resulting in net proceeds to the Company of $43.4 million after deducting sales agent commissions and expenses. In November 2022, the Company filed a new prospectus supplement to the 2021 Shelf Registration Statement for the offer and sale of up to $100.0 million of shares of common stock from time to time through the sales agent, which includes the $30.0 million of shares of common stock not sold under the original prospectus and up to an additional $70.0 million of shares of common stock (the ATM Program). No shares of common stock have been sold to date under the ATM Program. The Company expects that its cash and cash equivalents, including the net proceeds it received from its ATM offering, will be sufficient to fund its forecasted operating expenses, capital expenditure requirements and debt service payments for at least the next twelve months from the issuance of these interim consolidated financial statements. All of the Company’s revenue to date has been generated from a collaboration and license agreement with Regeneron Pharmaceuticals Inc, (Regeneron). The Company does not expect to generate any significant product revenue until it obtains regulatory approval of and commercializes any of the Company’s product candidates or enters into additional collaborative agreements with third parties, and it does not know when, or if, either will occur. The Company expects to continue to incur significant losses for the foreseeable future, and it expects the losses to increase as the Company continues the development of, and seeks regulatory approvals for, its product candidates and begins to commercialize any approved products. The Company is subject to all of the risks typically related to the development of new product candidates, including, but not limited to, raising additional capital, development by its competitors of new technological innovations, risk of failure in preclinical and clinical studies, safety and efficacy of its product candidates in clinical trials, the risk of relying on external parties such as contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs), the regulatory approval process, market acceptance of the Company’s products once approved, lack of marketing and sales history, dependence on key personnel and protection of proprietary technology and it may encounter unforeseen expenses, difficulties, complications, delays, and other unknown factors that may adversely affect its business. Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through the sale of equity, debt financings, collaborative or other arrangements with corporate or other sources of financing. Adequate funding may not be available to the Company on acceptable terms or at all. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and the Company’s ability to pursue its business strategies. Although the Company continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

Organization and Nature of Business

9 Months Ended

Sep. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Organization and Nature of the Business

Adicet Bio, Inc. (formerly resTORbio, Inc. (resTORbio), together with its subsidiaries, the Company) is a clinical stage biotechnology company discovering and developing allogeneic gamma delta T cell therapies for cancer. The Company is advancing a pipeline of “off-the-shelf” gamma delta T cells, engineered with chimeric antigen receptors (CARs) to enhance selective tumor targeting and facilitate innate and adaptive anti-tumor immune response for durable activity in patients. The Company's approach to activate, engineer, and manufacture allogeneic gamma delta T cell product candidates derived from the peripheral blood cells of unrelated donors allows it to generate new product candidates in a rapid and cost-efficient manner.

Adicet Bio, Inc. (when referred to prior to the merger, Former Adicet) was incorporated in November 2014 in Delaware. On September 15, 2020, Former Adicet completed a merger (Merger) with resTORbio, pursuant to which Former Adicet merged with a wholly owned subsidiary of resTORbio in an all-stock transaction with Former Adicet surviving as a wholly owned subsidiary of resTORbio and changing its name to “Adicet Therapeutics, Inc.” (Adicet Therapeutics). In connection with the Merger, the Company changed its name from “resTORbio, Inc.” to “Adicet Bio, Inc.” The Company’s principal executive offices are located in Boston, Massachusetts. The Company also has offices in Redwood City, California.

Adicet Bio Israel Ltd. (formerly Applied Immune Technologies Ltd.) (Adicet Israel) is a wholly owned subsidiary of the Company and is located in Haifa, Israel. Adicet Israel was founded in 2006. During 2019, the Company consolidated its operations, including research and development activities, in the United States and as a result, substantially reduced its operations in Israel.

Liquidity

The Company has incurred significant net operating losses and negative cash flows from operations and has an accumulated deficit of $351.3 million as of September 30, 2023. The Company has historically financed its operations primarily through a collaboration and licensing arrangement, public and private placements of equity securities and debt, and cash received in the Merger with resTORbio. To date, none of the Company’s product candidates have been approved for sale and therefore the Company has not generated any revenue from product sales. Management expects operating losses and negative cash flows to continue for the foreseeable future, until such time, if ever, that it can generate significant sales of its product candidates currently in development.

On March 12, 2021, the Company entered into a Capital On Demand™ Sales Agreement (the Sales Agreement) with JonesTrading Institutional Services LLC, as sales agent, to provide for the offering, issuance and sale of up to an aggregate amount of $75.0 million of shares of common stock from time to time in “at-the-market” (ATM) offerings under a registration statement on Form S-3 (File No. 333-254193) (2021 Shelf Registration Statement) filed with the U.S. Securities and Exchange Commission (the SEC), which was declared effective on March 30, 2021. In August 2022, pursuant to the Sales Agreement and subject to the limitations thereof, the Company sold an aggregate of 2,611,723 shares of common stock at $17.23 per share resulting in net proceeds to the Company of $43.4 million after deducting sales agent commissions and expenses. In November 2022, the Company filed a new prospectus supplement to the 2021 Shelf Registration Statement for the offer and sale of up to $100.0 million of shares of common stock from time to time through the sales agent, which includes the $30.0 million of shares of common stock not sold under the original prospectus and up to an additional $70.0 million of shares of common stock (the ATM Program). No shares of common stock have been sold to date under the ATM Program.

The Company expects that its cash and cash equivalents, including the net proceeds it received from its ATM offering, will be sufficient to fund its forecasted operating expenses, capital expenditure requirements and debt service payments for at least the next twelve months from the issuance of these interim consolidated financial statements.

All of the Company’s revenue to date has been generated from a collaboration and license agreement with Regeneron Pharmaceuticals Inc, (Regeneron). The Company does not expect to generate any significant product revenue until it obtains regulatory approval of and commercializes any of the Company’s product candidates or enters into additional collaborative agreements with third parties, and it does not know when, or if, either will occur. The Company expects to continue to incur significant losses for the foreseeable future, and it expects the losses to increase as the Company continues the development of, and seeks regulatory approvals for, its product candidates and begins to commercialize any approved products. The Company is subject to all of the risks typically related to the development of new product candidates, including, but not limited to, raising additional capital, development by its competitors of new technological innovations, risk of failure in preclinical and clinical studies, safety and efficacy of its product candidates in clinical trials, the risk of relying on external parties such as contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs), the regulatory approval process, market acceptance of the Company’s products once approved, lack of marketing

and sales history, dependence on key personnel and protection of proprietary technology and it may encounter unforeseen expenses, difficulties, complications, delays, and other unknown factors that may adversely affect its business.

Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through the sale of equity, debt financings, collaborative or other arrangements with corporate or other sources of financing. Adequate funding may not be available to the Company on acceptable terms or at all. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and the Company’s ability to pursue its business strategies. Although the Company continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.