Precigen Reports Positive Outcomes for Rare Respiratory Disease Drug Candidate

Precigen's drug for rare respiratory disease shows durable outcomes. The biopharmaceutical company, which operates in immuno-oncology, autoimmune disorders, and infectious diseases, has a pipeline of therapies across multiple indications. Its Biopharmaceuticals segment includes Precigen and ActoBio, while Exemplar is focused on developing research models and services for healthcare research applications.

Precigen, Inc. (Nasdaq: PGEN), a biopharmaceutical company specializing in precision medicines, has announced long-term follow-up data demonstrating the durability of its PAPZIMEOS™ (zopapogene imadenovec-drba) therapy for adults with recurrent respiratory papillomatosis (RRP). The data were presented at the American Academy of Otolaryngology–Head and Neck Surgery Foundation (AAO-HNSF) 2025 Annual Meeting Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1].

The pivotal study of PAPZIMEOS, which led to its FDA approval in August 2025, showed that 51% of study patients achieved complete response, requiring no surgeries in the 12-month period after treatment. In the long-term follow-up study, 15 out of 18 complete responders (83%) maintained ongoing complete responses as of the September 19, 2025 data cutoff, with a median follow-up duration of 36 months Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1].

Notably, the study observed a reduction in surgeries compared to the year prior to treatment, with 86% of patients in Year 1, 91% in Year 2, and 95% in Year 3 experiencing a decrease in the number of surgeries Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1]. No new safety events were observed during the long-term follow-up period.

Helen Sabzevari, PhD, President and CEO of Precigen, commented on the significance of these results, stating, "The updated durability data reinforce that PAPZIMEOS is not only a medical breakthrough but a transformative therapy for the RRP community" Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1].

RRP is a rare, debilitating disease caused by chronic HPV 6 or HPV 11 infection, leading to severe voice disturbance, compromised airways, and recurrent post-obstructive pneumonia. Management of RRP has primarily consisted of repeated surgeries, which do not address the underlying cause and can be associated with significant morbidity and patient burden Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1].

PAPZIMEOS is a non-replicating adenoviral vector-based immunotherapy designed to generate an immune response against HPV 6 and HPV 11 proteins in patients with RRP. It is the first and only FDA-approved therapy for adults with RRP, addressing the root cause of the disease Precigen Announces Long-Term Follow-Up Results Highlighting Ongoing Durable Complete Responses after Treatment with PAPZIMEOS, the First and Only FDA-approved Therapy for Adults with Recurrent Respiratory Papillomatosis^[1].

The long-term data from the pivotal study support the potential for PAPZIMEOS to reduce the need for repeated surgeries, improve patient quality of life, and lower healthcare system burden. This is a significant development for patients and healthcare providers, as it addresses a previously unmet medical need in the treatment of RRP.