FDA approves Papzimeos (zopapogene imadenovec) for the treatment of adults with recurrent respiratory papillomatosis – Precigen

Precigen, Inc. announced that the FDA has approved Papzimeos (zopapogene imadenovec-drba) for the treatment of adults with recurrent respiratory papillomatosis (RRP). Papzimeosis the first and only FDA-approved therapy for the treatment of adults with RRP. Precigen completed submission of the rolling Biologics License Application (BLA) in December 2024 under an accelerated approval pathway; however, the FDA has granted Papzimeos full approval, which does not require a confirmatory clinical trial. Papzimeos is a non-replicating adenoviral vector-based immunotherapy designed to express a fusion antigen comprising selected regions of human papillomavirus (HPV) types 6 and 11 proteins—the root cause of RRP. Papzimeos is delivered via four subcutaneous injections over a 12-week interval.

The approval is supported by data from the open-label, single-arm, pivotal study in adult patients with RRP:

• • The pivotal study successfully met its primary safety and pre-specified primary efficacy endpoints.
• • 51% (18 out of 35) of study patients achieved Complete Response, requiring no surgeries in the 12 months after treatment with PAPZIMEOS. These Complete Responses remained durable for over 12 months. Of the 18 patients with a Complete Response in the ongoing study, 15 patients evaluated at 24 months demonstrated continued Complete Response.
• • Papzimeos was well-tolerated with no dose-limiting toxicities and no treatment-related adverse events greater than Grade 2.
• • Papzimeos induced HPV 6/11-specific T cell responses in RRP study patients with a significantly greater expansion of peripheral HPV-specific T cells in responders compared with non-responders.

The pivotal study was led by lead investigators, Drs Clint T. Allen,and Scott M. Norberg at the National Institutes of Health. Pivotal data were presented at the 2024 American Society of Clinical Oncology (ASCO) annual meeting and published in The Lancet Respiratory Medicine .

“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. 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,” said Helen Sabzevari, PhD, President and CEO of Precigen. “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.”

“This long-awaited FDA approval represents a momentous milestone for the RRP community,” said Kim McClellan, President of the Recurrent Respiratory Papillomatosis Foundation. “For the first time, adult patients with RRP have access to an FDA-approved therapy that offers the potential to reduce—or even eliminate—endless repeated surgeries. This breakthrough brings long-overdue hope to patients and families who have endured so much. We are deeply grateful to the teams at Precigen and the NIH, and above all, to the patients and caregivers whose courage, advocacy, and perseverance have made this historic moment possible.”

See citation- Norberg SM , Valdez J et al. PRGN-2012 gene therapy in adults with recurrent respiratory papillomatosis: a pivotal phase 1/2 clinical trial. Lancet Respir Med 2025. 13,: 318 DOI: 10.1016/S2213- 2600 (24)00368-0