• Strategically Focused Company Structure to Prioritize Clinical Development and Deliver Critical, Clinical-Stage Data
• SQZ^® eAPC Phase 1/2 Trial Enrollment on Track; Anticipate Data for the Highest-Dose Monotherapy Cohort in Mid-2023
• Phase 1 SQZ-AAC-HPV-101 Clinical Trial to Continue Following the Recent Observation of a Confirmed Complete Response in the First Patient in the Lowest-Dose Cohort; Anticipate Data for the Highest-Dose Cohort in the Fourth Quarter of 2023

WATERTOWN, Mass. / Mar 22, 2023 / Business Wire / SQZ Biotechnologies Company (NYSE: SQZ), focused on unlocking the full potential of cell therapies, today reported full year 2022 financial results and recent portfolio updates.

"The team is focused on our key initiatives of advancing our SQZ^® eAPC and SQZ^® AAC programs,” said Howard Bernstein, M.D., Ph.D., Interim Chief Executive Officer and Member of the Board of Directors. “After the restructuring in December, we made important changes to align our talent to fully support our clinical development efforts—we are now primed to deliver on multiple clinical milestones over the next 12 months. We are encouraged by the observation of a confirmed complete response in the first patient in the lowest-dose cohort our AAC trial and have therefore decided to continue the AAC trial. We remain focused on optimizing the potential of our eAPC and AAC platforms to meet the significant unmet medical needs of patients with HPV16+ tumors. We look forward to data from both these programs later in the year.”

2022 Full Year and Recent Portfolio Updates

Clinical Programs:
SQZ^® Enhanced Antigen Presenting Cell (“eAPC”) Platform in Oncology

• Received FDA fast track designation for the treatment of HPV16+ tumors
• Stable disease observed in two out of four evaluable patients in eAPC Phase 1/2 trial including a pronounced pharmacodynamic response in a patient with prolonged stable disease
• Interim results from the ongoing SQZ^® eAPC Phase 1/2 trial showed favorable safety data and the investigational therapy was generally well tolerated
• Strong enrollment rate on track to report clinical data for the highest-dose monotherapy cohort in the middle of 2023

SQZ^® Activating Antigen Carriers (“AAC”) Platform in Oncology

• A confirmed complete response (CR), by RECIST 1.1 criteria, was observed in the first patient in the lowest-dose cohort of the SQZ-AAC-HPV-101 Phase 1 clinical trial for HPV16+ solid tumors
• In light of the response, the company has decided to continue to enroll patients in the SQZ-AAC-HPV-101 clinical trial; Two additional patients have been dosed in the lowest-dose cohort and the dose-limiting toxicity (DLT) period has been completed
• The recommendation of the Study Safety Committee is for the company to move directly to enrolling patients in the highest-dose cohort
• Initial clinical data from the highest-dose cohort is anticipated in the fourth quarter of 2023
• Published comprehensive preclinical research in Frontiers in Immunology

Earlier Stage Programs:

• The company will continue to explore partnerships and collaborations for its earlier stage assets and programs, including SQZ^® Tolerizing Antigen Carriers (“TAC”) Platform in Immune Tolerance

2022 Full Year Financial Highlights

• Revenue for the year ended December 31, 2022, was $21.5 million compared to $27.1 million for the year ended December 31, 2021
• Research and development expenses for the year ended December 31, 2022, were $71.0 million compared to $70.1 million for the year ended December 31, 2021
• General and administrative expenses for the year ended December 31, 2022, were $26.3 million compared to $25.7 million for the year ended December 31, 2021
• Restructuring charges for the year ended December 31, 2022, were $4.9 million, primarily composed of $4.1 million in one-time termination benefits payable to employees included in the 60% workforce reduction, and $0.8 million in non-cash restructuring charges.
• Net loss for the year ended December 31, 2022, was $79.5 million, compared to $68.7 million for the year ended December 31, 2021
• As of December 31, 2022, the Company had cash and cash equivalents of $63.7 million and anticipates this will be sufficient to fund operating expenses and capital expenditure requirements into 2024

An updated investor presentation is available on the Events & Presentations page within the investor relations section of the company’s corporate website, investors.sqzbiotech.com. Based on guidance from the SEC, investors should note that the company may utilize its corporate website to post updated corporate and scientific presentations. It is possible that the information posted there could be deemed to be material information.

About SQZ Biotechnologies

SQZ Biotechnologies is a clinical-stage biotechnology company focused on unlocking the full potential of cell therapies. The company’s proprietary Cell Squeeze^® technology offers the unique ability to deliver multiple biological materials into many patient cell types to engineer what the company believes can be a broad range of potential therapeutics. The company’s goal is to create well-tolerated cell therapies that can provide therapeutic benefit for patients and improve the patient experience over existing cell therapy approaches. With production timelines under 24 hours and the opportunity to eliminate preconditioning and lengthy hospital stays, the company believes its approach could change the way people think about cell therapies. For more information, please visit www.sqzbiotech.com.

Forward Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements relating to the timing and outcome of the company’s clinical trials, clinical safety and efficacy of its therapeutic candidates and the potential addressable market for the company’s therapeutic candidates. These forward-looking statements are based on management's current expectations. Actual results could differ from those projected in any forward-looking statements due to several risk factors. Such factors include, among others, risks and uncertainties related to the company’s significant losses incurred since inception and expectation to incur significant additional losses for the foreseeable future; the company’s need for additional funding; our ability to continue as a going concern; our ability to successfully execute and achieve the anticipated benefits of our restructuring plan; the development of the company’s initial product candidates, upon which its business is highly dependent; the impact of the COVID-19 pandemic on the company’s operations and clinical activities; the lengthy, expensive, and uncertain process of clinical drug development, including uncertain outcomes of clinical trials and potential delays in regulatory approval; and protection of the company’s proprietary technology, intellectual property portfolio and the confidentiality of its trade secrets. These and other important factors discussed under the caption "Risk Factors" in the company’s Quarterly Report on Form 10-Q, the company’s Annual Report on Form 10-K, and other filings with the U.S. Securities and Exchange Commission could cause actual results to differ materially from those indicated by the forward-looking statements. Any forward-looking statements represent management's estimates as of this date and the company undertakes no duty to update these forward-looking statements, whether as a result of new information, the occurrence of current events, or otherwise, unless required by law.