Precigen Inc. (NASDAQ: PGEN) received orphan drug exclusivity from the FDA for PAPZIMEOS, its treatment for recurrent respiratory papillomatosis (RRP), extending market protection through August 2032.

The exclusivity prevents FDA approval of similar drugs for RRP for seven years. RRP is a rare respiratory disease affecting fewer than 200,000 people in the United States, where patients typically undergo multiple surgeries annually to remove benign tumors in the respiratory tract.

PAPZIMEOS uses a modified adenovirus to train the immune system to target proteins in HPV 6 and HPV 11, which cause RRP. The drug is currently available commercially in the United States and prescribed at medical centers and community practices nationwide.

Precigen presented long-term data from its pivotal study at the 2026 American Society of Clinical Oncology Annual Meeting. The data showed 15 of 18 complete responders, or 83%, maintained complete responses for at least 36 months without additional RRP treatment. Five patients remained treatment-free after four years.

"The presentation at ASCO marks an important maturation of the PAPZIMEOS pivotal study data, with all complete responders now followed for at least 36 months, 83% with ongoing response, including 5 patients who are surgery-free beyond 4 years," said Helen Sabzevari, Precigen's president and CEO.

Participants received no additional RRP treatments, including surgery or investigational treatments, during the follow-up period. No new safety events occurred during long-term follow-up, according to the company's statement.