UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File No. 001-38359 Adicet Bio, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3305277 (State or other jurisdiction ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File No. 001-38359 Adicet Bio, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3305277 (State or other jurisdiction of in ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 | --- | --- | --- | --- | --- | |----------------|--------------------|-----------------------------------------------------------|---------------------------------------------------------- ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File No. 001-38359 Adicet Bio, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3305277 (State or other jurisdiction of incorp ...

PART I. FINANCIAL INFORMATION This section presents the unaudited consolidated financial statements and management's analysis of financial condition and operations [Consolidated Financial Statements (Unaudited)](index=7&type=section&id=Item%201.%20Consolidated%20Financial%20Statements%20(Unaudited)) The unaudited consolidated financial statements show increased cash and assets due to a public offering, with continued net losses driven by rising R&D expenses [Consolidated Balance Sheets](index=7&type=section&id=Consolidated%20Balance%20Sheets) The balance sheets reflect a significant increase in cash and total assets primarily from financing activities Consolidated Balance Sheet Highlights (in thousands) | Account | Sep 30, 2021 | Dec 31, 2020 | | :--- | :--- | :--- | | **Assets** | | | | Cash and cash equivalents | $192,226 | $84,330 | | Total current assets | $199,025 | $100,336 | | Total assets | $257,195 | $153,835 | | **Liabilities & Equity** | | | | Total current liabilities | $20,032 | $22,479 | | Total liabilities | $39,971 | $44,008 | - Cash and cash equivalents significantly increased from **$84.3 million** at the end of 2020 to **$192.2 million** as of September 30, 2021, reflecting proceeds from financing activities during the period[20](index=20&type=chunk) [Consolidated Statements of Operations and Comprehensive Loss](index=8&type=section&id=Consolidated%20Statements%20of%20Operations%20and%20Comprehensive%20Loss) The statements show increased R&D expenses and a higher net loss, while revenue decreased due to milestone timing Statement of Operations Summary (in thousands, except per share data) | Metric | Three Months Ended Sep 30, 2021 | Three Months Ended Sep 30, 2020 | Nine Months Ended Sep 30, 2021 | Nine Months Ended Sep 30, 2020 | | :--- | :--- | :--- | :--- | :--- | | Revenue—related party | $3,429 | $3,028 | $4,262 | $12,493 | | Research and development | $11,926 | $8,942 | $34,285 | $24,651 | | General and administrative | $5,213 | $7,741 | $15,868 | $17,684 | | Loss from operations | $(13,710) | $(13,655) | $(45,891) | $(29,842) | | Net loss | $(14,013) | $(14,779) | $(46,186) | $(27,720) | | Net loss per share | $(0.44) | $(2.84) | $(1.54) | $(8.69) | - Research and development expenses increased to **$34.3 million** for the nine months ended Sep 30, 2021, up from **$24.7 million** in the prior year period, reflecting increased clinical development activities[23](index=23&type=chunk) - Revenue for the nine months ended Sep 30, 2021, decreased significantly to **$4.3 million** from **$12.5 million** in the prior year period, primarily due to the timing of milestone achievements under the Regeneron agreement[23](index=23&type=chunk)[195](index=195&type=chunk) [Consolidated Statements of Cash Flows](index=11&type=section&id=Consolidated%20Statements%20of%20Cash%20Flows) Cash flows indicate significant funding from financing activities, offsetting operational cash burn and driving overall cash increase Cash Flow Summary (in thousands) | Activity | Nine Months Ended Sep 30, 2021 | Nine Months Ended Sep 30, 2020 | | :--- | :--- | :--- | | Net cash used in operating activities | $(37,608) | $(28,207) | | Net cash provided by investing activities | $282 | $102,769 | | Net cash provided by financing activities | $145,222 | $36 | | Net change in cash | $107,896 | $74,598 | - Financing activities provided **$145.2 million** in cash for the first nine months of 2021, primarily from the issuance of common stock, which was the main driver of the increase in the company's cash position[32](index=32&type=chunk)[225](index=225&type=chunk) - Investing activities in the first nine months of 2020 included **$64.1 million** in cash acquired from the Merger with resTORbio, which was not present in 2021[32](index=32&type=chunk)[224](index=224&type=chunk) [Management's Discussion and Analysis of Financial Condition and Results of Operations](index=32&type=section&id=Item%202.%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses the company's clinical-stage progress, financial performance, and liquidity, highlighting increased R&D and a strengthened cash position - The company is developing "off-the-shelf" gamma delta T cell therapies, with its lead product candidate, ADI-001, in a Phase 1 clinical trial for Non-Hodgkin's Lymphoma (NHL) initiated in March 2021[156](index=156&type=chunk) - Interim clinical data from the initial dose escalation portion of the ADI-001 study is expected by the **end of 2021**[156](index=156&type=chunk) - The company plans to file an Investigational New Drug (IND) application for ADI-002, its first solid tumor candidate, in the **second quarter of 2022** and initiate Phase 1 trials in the **second half of 2022**[156](index=156&type=chunk) - In February 2021, the company raised approximately **$128.7 million** in net proceeds from an underwritten public offering and an additional **$15.0 million** from a concurrent private placement[161](index=161&type=chunk)[162](index=162&type=chunk) [Results of Operations](index=37&type=section&id=Results%20of%20Operations) Operating results show increased R&D expenses and a decrease in revenue, contributing to a higher net loss Comparison of Operating Results (in thousands) | Metric | Three Months Ended Sep 30, 2021 | Three Months Ended Sep 30, 2020 | Nine Months Ended Sep 30, 2021 | Nine Months Ended Sep 30, 2020 | | :--- | :--- | :--- | :--- | :--- | | Revenue – related party | $3,429 | $3,028 | $4,262 | $12,493 | | Research and development | $11,926 | $8,942 | $34,285 | $24,651 | | General and administrative | $5,213 | $7,741 | $15,868 | $17,684 | | Net loss | $(14,013) | $(14,779) | $(46,186) | $(27,720) | - R&D expenses for the nine months ended Sep 30, 2021 increased by **$9.6 million (39%)** compared to the same period in 2020, driven by a **$4.0 million** increase in payroll/personnel costs from higher headcount, a **$2.1 million** increase in stock-based compensation, and increased CRO and facility expenses related to ADI-001 development[198](index=198&type=chunk) - G&A expenses for the nine months ended Sep 30, 2021 decreased by **$1.8 million (10%)** compared to the prior year period, mainly due to a **$5.9 million** reduction in professional fees associated with the 2020 Merger, partially offset by higher payroll, insurance, and facility costs[199](index=199&type=chunk) - Revenue for the nine months ended Sep 30, 2021 decreased by **$8.2 million (66%)** year-over-year, primarily due to a **$10.0 million** milestone payment in June 2020 and a **$4.0 million** revenue reduction in Q1 2021 from an extended performance obligation timeline[195](index=195&type=chunk)[196](index=196&type=chunk) [Liquidity and Capital Resources](index=40&type=section&id=Liquidity%20and%20Capital%20Resources) The company's cash position significantly improved due to recent financing, providing sufficient funds for the next twelve months - As of September 30, 2021, the company had **$192.2 million** in cash and cash equivalents[205](index=205&type=chunk) - The company believes its current cash and cash equivalents are sufficient to fund operations, capital expenditures, and debt service for at least the **next twelve months** from the report's issuance date[206](index=206&type=chunk)[212](index=212&type=chunk) - The company has a loan agreement with Pacific Western Bank for up to **$15.0 million**, primarily for financing leasehold improvements, with no funds drawn as of September 30, 2021[206](index=206&type=chunk)[207](index=207&type=chunk) - As of September 30, 2021, the company had an accumulated deficit of **$152.5 million**[211](index=211&type=chunk) [Quantitative and Qualitative Disclosures About Market Risk](index=45&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) The company's primary market risk is interest rate exposure on cash equivalents, deemed immaterial due to short-term, low-risk investments - The company's main market risk stems from potential adverse changes in interest rates on its **$192.2 million** of cash and cash equivalents[237](index=237&type=chunk) - Due to the short-term maturities and low-risk profile of its cash equivalents, the company does not expect a **10%** change in interest rates to materially affect its fair value or future interest income[237](index=237&type=chunk) [Controls and Procedures](index=45&type=section&id=Item%204.%20Controls%20and%20Procedures) Material weaknesses in internal controls were identified, leading to ineffective disclosure controls, with remediation efforts underway - Management identified material weaknesses in internal control over financial reporting during the preparation of its financial statements for the quarter ended September 30, 2021[240](index=240&type=chunk) - The identified weaknesses include: - Lack of sufficient accounting professionals with appropriate experience - Lack of formal accounting policies, procedures, and monitoring controls - Ineffective controls over segregation of duties - Lack of formal processes to account for complex transactions[242](index=242&type=chunk) - Due to these material weaknesses, the CEO and CFO concluded that the company's disclosure controls and procedures were not effective as of September 30, 2021[243](index=243&type=chunk) - Remediation efforts are underway, including hiring a permanent VP Corporate Controller, implementing a new ERP system (Microsoft 365 Business Central) in January 2021, and re-evaluating and implementing additional internal controls[245](index=245&type=chunk) PART II. OTHER INFORMATION This section details legal proceedings, significant risk factors, and the exhibits filed with the report [Legal Proceedings](index=48&type=section&id=Item%201.%20Legal%20Proceedings) The company is not currently involved in any legal proceedings expected to materially impact its financial condition or operations - The company is not currently party to any legal proceedings that it expects to have a material adverse impact on its financial condition or operations[249](index=249&type=chunk) [Risk Factors](index=48&type=section&id=Item%201A.%20Risk%20Factors) The company faces substantial risks including clinical trial uncertainties, manufacturing dependencies, financial control weaknesses, and reliance on key collaborations - The company's business is highly dependent on the success of its two lead product candidates, ADI-001 and ADI-002, which are based on novel gamma delta T cell technologies with significant development and regulatory challenges[3](index=3&type=chunk)[259](index=259&type=chunk)[265](index=265&type=chunk) - The company has a history of net losses (**$152.5 million** accumulated deficit as of Sep 30, 2021) and expects to incur substantial losses for the foreseeable future[254](index=254&type=chunk) - Adicet relies on third-party manufacturers for its product candidates, which increases risks related to supply, cost, and quality control, potentially impairing development and commercialization efforts[4](index=4&type=chunk)[300](index=300&type=chunk) - Material weaknesses have been identified in the company's internal control over financial reporting, which could harm the business and negatively impact stock value[5](index=5&type=chunk)[353](index=353&type=chunk) - The collaboration with Regeneron is critical; termination of the agreement or a material breach by Regeneron would materially harm the company's business and financial condition[6](index=6&type=chunk)[357](index=357&type=chunk) [Exhibits](index=90&type=section&id=Item%206.%20Exhibits) This section lists key exhibits filed, including corporate agreements and officer certifications - Key filed exhibits include a Sublease Agreement dated July 19, 2021, and a Fourth Amendment to the Loan and Security Agreement with Pacific Western Bank, dated October 21, 2021[486](index=486&type=chunk) - The report includes certifications from the Principal Executive Officer and Principal Financial Officer as required by Sections 302 and 906 of the Sarbanes-Oxley Act[486](index=486&type=chunk)