FDA Approves Precigen’s Recurrent Respiratory Papillomatosis Treatment

Rare Daily Staff

The U.S. Food and Drug Administration has approved Precigen’s Papzimeos, making it the first FDA-approved treatment for adults with recurrent respiratory papillomatosis, a rare condition that can require multiple throat surgeries annually to clear the airway.

The FDA granted Papzimeos full approval without requiring a confirmatory clinical trial, even though the company applied through the agency’s accelerated approval pathway.

RRP is a rare, potentially life-threatening disease of the upper and lower respiratory tract caused by chronic infection with human papillomavirus type 6 or type 11. It can lead to severe voice problems, airway obstruction, and repeated bouts of pneumonia. Treatment has mainly involved repeated surgeries, which do not address the underlying cause and can carry significant risks and burdens for patients and the healthcare system.

Papzimeos is a nonreplicating adenoviral vector-based immunotherapy designed to target the root cause of RRP. It delivers a fusion antigen containing selected regions of HPV type 6 and type 11 proteins. The therapy is given in four subcutaneous injections over 12 weeks and is intended to generate an immune response against the virus.

Approval was based on data from an open-label, single-arm pivotal study in adults with RRP. The trial met its primary safety and efficacy goals, with 51 percent of participants achieving a complete response — meaning no surgeries were needed in the year following treatment. Of the 18 patients with a complete response, 15 maintained that result through 24 months. The drug was well tolerated with no dose-limiting toxicities.

“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 — repeated surgeries. This breakthrough brings long-overdue hope to patients and families who have endured so much.”

Photo: Kim McClellan, president of the Recurrent Respiratory Papillomatosis Foundation