FDA Approves Precigen’s Recurrent Respiratory Papillomatosis Gene Therapy Papzimeos

The FDA has approved Precigen’s zopapogene imadenovec-drba (PRGN-2012), a nonreplicating adenoviral vector-based immunotherapy, for treating adults with recurrent respiratory papillomatosis (RRP).¹ The therapy will be marketed under the name Papzimeos.

Papzimeos, which is administered over a 12-week timeframe through 4 subcutaneous injections, is based on the company’s AdenoVerse platform and is intended to trigger an immune response targeted at cells infected by human papillomavirus (HPV) 6 or HPV 11, providing an alternative to the current standard of care for RRP, which typically involves repeated surgical interventions. The therapy was approved based on the results of a pivotal, open-label phase 1/2 clinical trial (NCT04724980). Notably, the FDA granted Papzimeosa full approval, without a requirement for a confirmatory trial to be conducted, even though Precigen had submitted the biologics license application (BLA) for the therapy via an accelerated approval pathway.

"For more than a century, since RRP was first recognized as a distinct disease, patients have had to rely on repeated surgeries to manage this relentless condition,” Helen Sabzevari, PhD, the president and CEO of Precigen, said in a statement.¹ “Today marks a historic turning point. With the landmark FDA approval of Papzimeos and broad label, all adult RRP patients are now eligible for access to the first and only approved therapy that targets the root cause of the disease. This milestone affirms the power of our AdenoVerse platform and the exceptional capabilities of our team to rapidly advance a wholly novel therapy from discovery to approval considerably faster than industry benchmarks. We are profoundly grateful to the NIH clinicians, the FDA, and—most importantly—the patients and families who made this breakthrough possible. We look forward to swiftly delivering Papzimeos to the RRP community and ushering in a new era of treatment that targets the underlying cause of the disease rather than just managing its symptoms."

Data from the phase 1/2 trial presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting, held May 31 to June 4, in Chicago, Illinois, showed that over 50% of patients (18 of 35) treated in the trial attained a complete response (CR) and over 85% of patients had a decrease in surgical interventions in the year after treatment with the gene therapy, when contrasted with the year before receiving the gene therapy.^1,2 The CR rate (CRR) was defined as the percentage of patients who did not require any RRP surgery during the 12 months after receiving the gene therapy. With regard to safety, it was reported that no dose-limiting toxicities had occurred, nor had any treatment-related adverse events of grade 2 or greater. The therapy was characterized as “well tolerated.”

“Randomized trials are not always needed to approve medical products, and this approval is proof of that philosophy,” Vinay Prasad, MD, MPH, the director of the FDA’s Center for Biologics Evaluation and Research (CBER), said in an FDA news release covering the agency’s decision.³ “The FDA will always demand the correct clinical study for the specific medical product and disease. Our requirements for products given to tens of millions of healthy people will be different than products given to at most hundreds or thousands of patients with unique diseases.”

Precigen noted that it has set up a patient support program for the newly approved therapy, referred to as Papzimeos SUPPORT, which will provide patients with insurance navigation, financial assistance, and other services.¹ The BLA for Papzimeos was originally accepted by the FDA with priority review in February 2025, following a rolling submission that had been completed in December 2024.^1,2

REFERENCES
1. Precigen announces full FDA approval of Papzimeos (zopapogene imadenovec-drba), the first and only approved therapy for the treatment of adults with recurrent respiratory papillomatosis. News release. Precigen, Inc. August 15, 2025. Accessed August 26, 2025. https://investors.precigen.com/news-releases/news-release-details/precigen-announces-full-fda-approval-papzimeos-zopapogene
2. FDA grants priority review to Precigen's BLA for PRGN-2012 for the treatment of adults with recurrent respiratory papillomatosis with PDUFA target action date set for August 27, 2025. News release. Precigen, Inc. February 25, 2025. Accessed August 26, 2025. https://investors.precigen.com/news-releases/news-release-details/fda-grants-priority-review-precigens-bla-prgn-2012-treatment
3. FDA approves first immunotherapy for recurrent respiratory papillomatosis. News release. FDA. August 14, 2025. Accessed August 26, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-immunotherapy-recurrent-respiratory-papillomatosis