Precigen, Inc. announced that the US Food and Drug Administration (FDA) has cleared the Investigational New Drug (IND) application to initiate a Phase 2 study of the first-in-class PRGN-2009 Off-the-Shelf (OTS) AdenoVerse™ immunotherapy in combination with pembrolizumab in patients with recurrent or metastatic cervical cancer. The Phase 2 randomized, open-label, two-arm, multicenter study will evaluate the efficacy and safety of PRGN-2009 in combination with pembrolizumab versus pembrolizumab monotherapy in patients with recurrent or metastatic cervical cancer who are pembrolizumab resistant. The study will enroll approximately 46 patients who previously have been treated with pembrolizumab for recurrent or metastatic disease.

In the Phase 1 study, PRGN-2009 was evaluated as a monotherapy (N=6) and in combination with a checkpoint inhibitor (N=11) in patients with recurrent or metastatic human papillomavirus (HPV)-associated cancers. Interim Phase 1 data showed a favorable safety profile of repeated PRGN-2009 administrations in both the monotherapy and the combination arms with no dose limiting toxicities (DLTs). Interim Phase 1 data showed encouraging clinical activity with objective responses when combined with a checkpoint inhibitor in heavily pre-treated recurrent/metastatic cancer patients who had previously failed checkpoint inhibitor treatment.

Full Phase 1 data will be presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting on June 3, 2023 from 8:00 to 11:00 AM CT (Abstract # 2628). Patients in the Phase 2 study will be randomized 1:1 to the combination of PRGN-2009 and pembrolizumab (cohort 1) or pembrolizumab monotherapy (cohort 2). Patients randomized to the PRGN-2009 plus pembrolizumab cohort will receive PRGN-2009 via subcutaneous (SC) injection (5 x 1011 PU every 3 weeks for three administrations followed by administration each 6 weeks thereafter).

Patients in the PRGN-2009 plus pembrolizumab cohort and pembrolizumab monotherapy cohort will receive pembrolizumab via intravenous (IV) infusion (400 mg every 6 weeks). Patients randomized to the pembrolizumab monotherapy cohort will be offered the option to crossover to the PRGN-2009 plus pembrolizumab cohort if certain conditions are met. The primary objective of the Phase 2 study is to assess the objective response rate (ORR) per RECIST v1.1 following treatment with PRGN-2009 in combination with pembrolizumab or pembrolizumab monotherapy.

Secondary objectives include the evaluation of safety and tolerability, progression-free survival (PFS), overall survival (OS), best overall responses (BOR), Disease Control Rate (DCR), time to response and duration of response.