Precigen, Inc. presented positive data at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting from the Phase 1 portion of the Phase 1/1b clinical study evaluating safety and efficacy of PRGN-3005 UltraCAR-T® in advanced stage platinum resistant ovarian cancer patients (Abstract# 5590 [2]). The presentation was delivered by John B. Liao, MD, PhD, Cancer Vaccine Institute, University of Washington Medicine, and a lead investigator for the PRGN-3005 clinical trial. PRGN-3005 UltraCAR-T is an autologous chimeric antigen receptor T (CAR-T) cell therapy manufactured using non-viral gene delivery and is under investigation for the treatment of patients with advanced, recurrent platinum resistant ovarian, fallopian tube or primary peritoneal cancer.

PRGN-3005 utilizes Precigen's transformative UltraCAR-T therapeutic platform, which eliminates ex vivo expansion and reduces manufacturing time to allow for rapid next day administration of UltraCAR-T cells following non-viral gene transfer. PRGN-3005 UltraCAR-T is a multigenic CAR-T cell investigational therapy utilizing Precigen's advanced non-viral gene delivery system to co-express a chimeric antigen receptor, membrane-bound interleukin-15 (mbIL15), and a kill switch for better precision and control. Conducted in collaboration with the University of Washington and Fred Hutchinson Cancer Research Center, the Phase 1 study has completed dose escalation, which evaluated the safety and efficacy of PRGN-3005 administered either via intraperitoneal (IP) or intravenous (IV) infusion, in the absence of lymphodepletion (LD) or IV following lymphodepletion with cyclophosphamide only (clinical trial identifier: NCT03907527).

The study population includes patients with advanced stage (III/IV) recurrent ovarian, fallopian tube, and primary peritoneal cancer who are platinum resistant and have progressed after receiving standard-of-care therapies or are not eligible to receive available therapies with known clinical benefit (Table 1). The mean age of patients in the study was 57.4 in the IP arm without lymphodepletion, 67.3 in the IV arm without lymphodepletion and 62.7 in the IV arm with lymphodepletion. Patients were heavily pretreated with a median of greater than or equal to 8 prior lines of therapy across all arms. Patients had significantly advanced stage disease with a high baseline tumor burden with most patients having distant metastases, including liver, spleen, bladder and lung.