Precigen, a biopharmaceutical company specialising in the advancement of innovative precision medicines, has received approval from the US Food and Drug Administration (FDA) for its immunotherapy PAPZIMEOS (zopapogene imadenovec-drba) for the treatment of adults with recurrent respiratory papillomatosis (RRP).

With this approval, PAPZIMEOS becomes the first and only FDA-approved therapy for the treatment of adults with RRP- a rare, debilitating, and potentially life-threatening disease of the upper and lower respiratory tract caused by chronic HPV 6 or HPV 11 infection.

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, eliminating the need for 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.

RRP can lead to severe voice disturbance, a compromised airway, and recurrent post-obstructive pneumonias. To date, management has relied mainly on repeated surgeries, which do not address the root cause of the disease and are associated with significant morbidity as well as significant patient and health system burden. 

Helen Sabzevari, PhD, President and CEO of Precigen, said, "For more than a century, since RRP was first recognised 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.”  

"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,” she added.

Kim McClellan, President of the Recurrent Respiratory Papillomatosis Foundation, described the FDA approval as a “momentous milestone for the RRP community.”

"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,” she said.

The FDA’s approval is based on data from an open-label, single-arm pivotal study in adult patients with RRP, which met its primary safety and pre-specified efficacy endpoints. More than half of the participants (18 of 35) achieved a complete response, requiring no surgeries in the 12 months following treatment with PAPZIMEOS. The therapy was well tolerated, with no dose-limiting toxicities and no treatment-related adverse events above Grade 2.

Precigen plans to begin promoting PAPZIMEOS immediately to help patients with RRP access the therapy. 

The company has also established Papzimeos SUPPORT, a comprehensive patient support program offering personalized services, including insurance navigation, financial assistance, and ongoing access support.