On Aug. 9, 2023, the U.S. Food and Drug Administration (FDA) issued confirmation of Precigen’s phase 1/2 study of PRGN-2012 AdenoVerse immunotherapy. This confirmation supports that the company’s single-arm study serves the purpose for it to file an accelerated approval request. The FDA also affirms that an additional randomized, placebo-controlled trial is not required. The biopharmaceutical company announced that it will conduct a confirmatory study based on the FDA’s response and guidance prior to submitting its biologics licensure application (BLA).
The pivotal study met its current primary endpoint of Complete Response rate, which was the percentage of participants who required no surgical intervention up to 12 months after PRGH-2012 treatment. It also accepted the study’s immunological surrogate marker, demonstrating production of HPV-specific T-cell responses following treatment.
“We are thankful for the FDA's decision, which underscores the importance of bringing innovative approaches for the treatment of this serious and rare disease," said Helen Sabzevari, PhD, president and CEO of Precigen.
Precigen developed PRGN-2012 for the treatment of recurrent respiratory papillomatosis (RRP), an uncommon, uncurable and hard-to-treat neoplastic disease. It is caused by infection of the respiratory tracts with HPV 6 or HPV 11, and it can sometimes be fatal. The therapeutic vaccine contains an optimized antigen design using Precigen’s adenovector technology, which is part of a proprietary platform. This helps to target cells infected with HPV 6 and HPV 11 to stimulate immune responses.
"The potential of this treatment is tremendously exciting for RRP patients,” said Kim McClellan, president of Recurrent Respiratory Papillomatosis Foundation. “The RRP community has only ever had one treatment option—surgery. The potential to eliminate even one surgery and improve the quality of our lives would have a profound impact on those living with RRP."
Phase 1 results demonstrated that 50% of adult RRP patients were “surgery free” during the 12- and 18-month post treatment follow-up periods. The phase 2 portion of the study met its enrollment and dosing eligibility, with a total of 35 patients at the recommended phase 2 dose. Patient follow-up of the study is ongoing, and Precigen expects to complete data collection by Q2 2024.
