Thursday, August 10, 2023
Precigen, Inc., traded on Nasdaq as PGEN, a biopharmaceutical firm dedicated to advancing gene and cell therapies to enhance patient lives, has made a significant announcement. The company disclosed that the US Food and Drug Administration (FDA) has given confirmation regarding the ongoing Phase 1/2 study (NCT04724980) for the experimental PRGN-2012 AdenoVerse™ immunotherapy. This confirmation establishes the study's pivotal role in seeking accelerated approval for the treatment of recurrent respiratory papillomatosis (RRP), a condition characterized by the growth of benign tumors in the respiratory tract. Importantly, the FDA has indicated that an additional randomized, placebo-controlled trial will not be required to support the submission of a biologics license application (BLA). In line with this regulatory insight, Precigen intends to conduct a confirmatory study before finalizing the BLA submission.
The FDA has expressly accepted the ongoing Phase 1/2 study's current primary endpoint, which measures the Complete Response rate. This rate signifies the proportion of patients who do not require surgical interventions during the 12 months following their treatment with PRGN-2012. Additionally, an immunological surrogate marker that demonstrates the induction of HPV-specific T cell responses after treatment with PRGN-2012 has been deemed suitable for inclusion in the accelerated approval request.
PRGN-2012 stands as an innovative therapeutic vaccine that employs Precigen's proprietary gorilla adenovector technology from the AdenoVerse platform. This approach stimulates immune responses targeted at cells infected with HPV 6 or HPV 11, the two strains most commonly linked to RRP. The unique advantages of gorilla adenovectors encompass the capability for repeat administration, an inability to replicate within the body (potentially enhancing safety), and effective delivery of a substantial genetic payload. It's noteworthy that PRGN-2012 has been granted Breakthrough Therapy Designation and Orphan Drug Designation by the FDA for its potential in treating RRP.
Notable findings from the Phase 1 portion of the study revealed that 50% of adult RRP patients who had undergone three or more surgeries within the year prior to treatment achieved a "surgery-free" state (Complete Response) following PRGN-2012 treatment. Moreover, these complete responders maintained their surgery-free status even at the 18-month mark post-treatment. The Phase 2 portion of the study, which involved 23 participants, has been successfully concluded, resulting in a total enrollment of 35 patients at the recommended Phase 2 dosage. Patient follow-up remains ongoing, with data collection anticipated to conclude by the second quarter of 2024.
Dr. Helen Sabzevari, President and CEO of Precigen, expressed gratitude for the FDA's decision, emphasizing its potential to accelerate the development timeline for PRGN-2012. She acknowledged the significance of introducing innovative solutions for the treatment of this rare and serious disease. Kim McClellan, President of the Recurrent Respiratory Papillomatosis Foundation, shared her enthusiasm about the treatment's prospects. Noting that the RRP community has historically been limited to surgery as a treatment option, she highlighted the potential of this therapy to reduce or eliminate the need for surgeries and thereby improve the quality of life for those affected by RRP.