FDA Fully Approves Precigen’s Papzimeos

Precigen, Inc., a biopharmaceutical company specializing in the advancement of innovative precision medicines to improve the lives of patients, announced that the US Food and Drug Administration (FDA) has approved Papzimeos (zopapogene imadenovec-drba) to treat adults with recurrent respiratory papillomatosis (RRP). This is the first and only FDA-approved therapy to treat 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. The treatment 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.

“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.”