Precigen Announces Positive Phase 1 Data for Off-the-Shelf PRGN-2009 AdenoVerse™ Immunotherapy Alone and in Combination with an Investigational Checkpoint Inhibitor in Patients with Recurrent/Metastatic HPV-associated Cancers

GERMANTOWN, Md., June 3, 2023

–  Recurrent/metastatic HPV-associated cancers (cervical, anal, oropharyngeal, etc.) are incurable by current therapies –

–  PRGN-2009 was safe and well-tolerated with only Grade 1 or 2 treatment related adverse events –

–  PRGN-2009 treatment induced HPV-specific T-cell immune responses and subsequently enhanced T-cell responses with repeat administrations without the development of neutralizing antibodies in the majority of patients –

GERMANTOWN, Md., June 3, 2023 /PRNewswire/ -- Precigen, Inc. (Nasdaq: PGEN), a biopharmaceutical company specializing in the development of innovative gene and cell therapies to improve the lives of patients, today presented positive clinical data from the Phase 1 study of the off-the-shelf (OTS) PRGN-2009 AdenoVerse^™ immunotherapy alone and in combination with an investigational anti-PDL1/TGF-Beta Trap checkpoint inhibitor (bintrafusp alfa) in patients with recurrent/metastatic (R/M) HPV-associated cancers (clinical trial identifier: NCT04432597) at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract# 2628).

"Recurrent/metastatic HPV-associated cancers such as cervical, anal, and oropharyngeal are incurable by current therapies and there remains significant unmet need for new safe and effective treatments. Checkpoint inhibitors alone have shown some promise, but have not produced durable responses and many patients relapse or become resistant," said Helen Sabzevari, PhD, President and CEO of Precigen. "In our Phase 1 study, combining PRGN-2009 with checkpoint inhibition demonstrated a favorable safety profile and resulted in a 30% ORR with prolonged duration of responses in patients with heavily pre-treated HPV-associated cancers, including those who were checkpoint blockade resistant. We are highly encouraged by these Phase 1 data and, as we announced on May 31, we are moving rapidly to initiate a Phase 2 study to combine PRGN-2009 with a checkpoint inhibitor to further investigate safety and efficacy in recurrent or metastatic cervical cancer. This new trial is the second Phase 2 for PRGN-2009 AdenoVerse, adding to the ongoing Phase 2 in oropharyngeal squamous cell carcinoma."

PRGN-2009 is an OTS investigational immunotherapy utilizing the AdenoVerse platform designed to activate the immune system to recognize and target HPV-positive (HPV⁺) solid tumors. PRGN-2009 is a novel, replication-incompetent gorilla adenovirus targeting HPV 16/18. PRGN-2009 can be administered repeatedly leading to enhancement of T-cells without increasing neutralizing antibodies. PRGN-2009 is under development through a Cooperative Research and Development Agreement, or CRADA, within the Center for Immuno-Oncology (CIO), Center for Cancer Research (CCR), National Cancer Institute (NCI), part of the National Institutes of Health (NIH).