FDA Approves Precigen’s Papzimeos Immunotherapy 51 Percent of RRP Patients Avoid Surgery for One Year

The US FDA has granted approval to Precigen’s breakthrough immunotherapy, Papzimeos, for adults suffering from recurrent respiratory papillomatosis (RRP), a rare and potentially fatal disease caused by HPV infection. This milestone marks the first-ever approved treatment for RRP, which until now has required patients to undergo repeated surgeries to remove obstructive, wart-like growths in the airway.

Clinical data showed that 51% of patients needed no surgeries in the 12 months following treatment, dramatically reducing the burden of frequent procedures. Shares of Precigen soared over 81% after the announcement.

Papzimeos works by activating the immune system against HPV types 6 and 11, which are responsible for the disease. With an estimated 27,000 adult RRP patients in the US, the approval brings hope to thousands who have faced years of repeated surgical interventions—some, like Kim McClellan, president of the RRP Foundation, have endured hundreds of operations since childhood.

Analysts project US peak sales for Papzimeos could reach $250 million. Experts hailed the FDA’s decision, noting that pivotal randomized trials were not required due to the compelling real-world results. For patients and physicians alike, the approval signals a new era in the management of rare respiratory diseases.