Precigen Reports Responses to PAPZIMEOS in Adults With Recurrent Respiratory Papillomatosis, Reinforcing FDA Approval

Author: Benzinga Newsdesk | October 13, 2025 06:12am

Precigen, Inc. (NASDAQ:PGEN), a biopharmaceutical company specializing in the advancement of innovative precision medicines to improve the lives of patients, today announced long-term follow-up data demonstrating durable responses to PAPZIMEOS™ (zopapogene imadenovec-drba) for the treatment of adults with recurrent respiratory papillomatosis (RRP). These data were presented at the American Academy of Otolaryngology–Head and Neck Surgery Foundation (AAO-HNSF) 2025 Annual Meeting. PAPZIMEOS was granted full approval by the United States Food and Drug Administration (FDA) in August 2025, becoming the first and only approved therapy for the treatment of adults with RRP.

PAPZIMEOS approval was supported by results from the pivotal study, which successfully met its primary safety and pre-specified primary efficacy endpoints. PAPZIMEOS was well-tolerated with no dose-limiting toxicities and no treatment-related adverse events greater than Grade 2. 51% (18 out of 35) of study patients achieved complete response (95% CI: 34-69%), requiring no surgeries in the 12-month period after treatment with PAPZIMEOS. Results from the pivotal clinical study of PAPZIMEOS were published in The Lancet Respiratory Medicine.

Key data highlights from the AAO-HNSF presentation:

• 15 out of the 18 complete responders (83%) in the pivotal study demonstrated ongoing complete responses as of the September 19, 2025 data cutoff, with:
  • Median duration of follow-up of 36 months (range: 27-37 months);
  • Median duration of complete response yet to be reached; and
  • No new safety events observed during long-term follow-up.
• Prolonged reduction in the requirement for surgical intervention to manage RRP was observed throughout long-term follow-up of evaluable study patients compared to the year prior to treatment. The percent of patients with a decrease in the number of surgeries, compared to pre-treatment was:
  • 86% in Year 1;
  • 91% in Year 2; and
  • 95% in Year 3.

"The updated durability data reinforce that PAPZIMEOS is not only a medical breakthrough but a transformative therapy for the RRP community," said Helen Sabzevari, PhD, President and CEO of Precigen. "For patients and their families, sustained responses mean freedom from the relentless cycle of repeat surgeries, reduction in the risk of surgical damage, and the possibility to improve quality of life. For physicians, it provides confidence in a safe and effective therapy that addresses the root cause of disease. And for the healthcare system, durable responses translate into fewer procedures, reduced complications, and lower long-term burden of care. This is precisely the type of impact we envisioned when we set out to develop what would become the first FDA-approved therapy for adults with RRP."

Posted In: PGEN