SQZ Biotechnologies Company (NYSE: SQZ), a cell therapy company developing novel treatments for multiple therapeutic areas, will present safety and tolerability, manufacturing, and antitumor activity data from its ongoing Phase 1 clinical trial of SQZ-PBMC-HPV-101 in patients with advanced or metastatic Human Papillomavirus Positive tumors at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, taking place June 4-8.

“These early data demonstrate the feasibility of our Cell Squeeze® technology and how it can potentially change the way the field thinks about cell therapies,” said Armon Sharei, Ph.D., Chief Executive Officer and Founder of SQZ Biotechnologies. “In this small number of patients whose cancer was very advanced, SQZ-PBMC-HPV-101 has been well-tolerated at all tested dose levels and demonstrated signals of increased immune activity. Importantly, we are also presenting evidence that we can efficiently and reproducibly manufacture our investigational therapy at scale, potentially making it more accessible to patients in need.”

The Phase 1 clinical trial data of SQZ-PBMC-HPV-101 being presented at ASCO includes three of the four planned monotherapy dose-escalating patient cohorts. Enrollment and evaluation of the monotherapy in the highest-dose cohort is ongoing. In the next stage of the trial, it is planned to combine SQZ-PBMC-HPV-101 with immune checkpoint inhibitors. The study’s primary outcome measures in the monotherapy stage of the trial are safety, tolerability, and the definition of the recommended phase 2 dose. Secondary outcome measures include antitumor activity and manufacturing feasibility.

Trial Highlights from ASCO Abstract 2536

Design, Safety, Tolerability and Patient Demographics

• SQZ-PBMC-HPV was given IV q 3 weeks on an outpatient basis and patients did not receive a prior conditioning regime
• The median number of lines of prior therapy was four, and all but one patient had previously received an immune checkpoint inhibitor
• SQZ-PBMC-HPV-101 was well-tolerated at all dose levels tested with patients receiving between two to 10 doses
• No dose-limiting toxicity or Grade 3 or higher treatment-related SAEs were observed

Manufacturing

• All batches of SQZ-PBMC-HPV-101 demonstrated HPV-specific CD8 T cell activation in vitro after thawing, and batch size allowed for treatment at the assigned dose regimen
• Quick and efficient manufacturing with all patient batches produced in less than 24 hours
• Investigational doses were released and available for administration approximately one week from the time a patient’s cells were drawn

Outcome and Biomarker

• Four patients achieved stable disease
• One patient who achieved stable disease remained on study for 42 weeks
• Preliminary analyses on pre- and post-therapy tumor biopsies indicated increased immune activity in select patients

Poster Presentation Details

Title: Initial Results of a first-in-human, dose escalation study of a cell-based vaccine in HLA A* 02+ patients with recurrent, locally advanced or metastatic HPV16+ solid tumors

First Author: Antonio Jimeno, M.D., Ph.D., University of Colorado Cancer Center

Abstract Number: 2536

Poster Session: Developmental Therapeutics -- Immunotherapy

Date and Time: A copy of the poster will be available on-demand starting Friday, June 4, 2021 at 8:00 am ET via the ASCO virtual meeting website.

SQZ-PBMC-HPV-101 Trial Design

SQZ-PBMC-HPV-101 is being evaluated in a Phase 1 clinical trial for the treatment of HPV16+ advanced or metastatic solid tumors. Patients must be positive for the human leukocyte antigen serotype HLA-A-*02. The investigational candidate, which targets E6 and E7 oncoproteins, is being studied as a monotherapy and in combination with immuno-oncology agents. The study’s primary outcome measures in the monotherapy and combination stages of the trial include safety, tolerability, and to define a recommended phase 2 dose. Antitumor activity is a secondary outcome measure in both the monotherapy and combination stages of the trial, and manufacturing feasibility is a secondary outcome measure in the monotherapy stage of the trial. The monotherapy phase of the study includes escalating dose cohorts with DLT measured over 28 days. The planned safety combination phase of the study will include SQZ-PBMC-HPV-101 and checkpoint inhibitors that have previously received regulatory approval. DLT will be measured over 42 days in the safety combination phase.

About Human Papillomavirus Positive Cancers

Human papillomavirus (HPV) is one of the most common viruses worldwide and certain strains persist for many years leading to cancer. According to the Centers for Disease Control (CDC), in the United States HPV+ tumors represent 3% of all cancers in women and 2% of all cancers in men, resulting in over 39,000 new cases of HPV+ tumors every year. HPV infection is larger outside of the U.S., and according to the International Journal of Cancer HPV+ tumors account for 4.5% of all cancers worldwide, resulting in approximately 630,000 new cases every year. According to the CDC, HPV infection plays a significant role in the formation of more than 90% of anal and cervical cancers, and most cases of vaginal (75%), oropharyngeal (70%), vulval (70%) and penile (60%) cancers.

About SQZ Biotechnologies

SQZ Biotechnologies is a clinical-stage biotechnology company developing transformative cell therapies for patients with cancer, infectious diseases, and other serious conditions. Using its proprietary technology, SQZ Biotechnologies offers the unique ability to deliver multiple materials into many patient cell types to engineer what we believe can be an unprecedented range of potential therapeutics for a variety of diseases. SQZ Biotechnologies has the potential to create well-tolerated cell therapies that can provide therapeutic benefit for patients and to improve the patient experience over existing cell therapy approaches. With accelerated production timelines under 24 hours and the opportunity to eliminate preconditioning and lengthy hospital stays, our goal is to use the SQZ™ approach to establish a new paradigm for cell therapies. Our first therapeutic applications aim to leverage the potential to generate target-specific immune responses, both in activation for the treatment of solid tumors and immune tolerance for the treatment of unwanted immune reactions and autoimmune diseases. For more information, please visit www.sqzbiotech.com.

Forward Looking Statement

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 upcoming events and presentations, our product candidates, preclinical and clinical activities, development plans, clinical safety and efficacy, regulatory compliance, and therapeutic impact. 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 our limited operating history; our significant losses incurred since inception and expectation to incur significant additional losses for the foreseeable future; the development of our initial product candidates, upon which our business is highly dependent; the impact of the COVID-19 pandemic on our operations and clinical activities; our need for additional funding and our cash runway; the lengthy, expensive, and uncertain process of clinical drug development, including uncertain outcomes of clinical trials and potential delays in regulatory approval; our ability to maintain our relationships with our third party vendors; and protection of our proprietary technology, intellectual property portfolio and the confidentiality of our trade secrets. These and other important factors discussed under the caption "Risk Factors" in our 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 SQZ 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.

Certain information contained in this press release relates to or is based on studies, publications, surveys and other data obtained from third-party sources and our own internal estimates and research. While we believe these third-party sources to be reliable as of the date of this press release, we have not independently verified, and we make no representation as to the adequacy, fairness, accuracy, or completeness of any information obtained from third-party sources.

View source version on businesswire.com: https://www.businesswire.com/news/home/20210519005943/en/