Precigen Reports Long-Term Efficacy of Papzimeos in Recurrent Respiratory Papillomatosis

Precigen reports durable responses with Papzimeos in recurrent respiratory papillomatosis, a condition caused by human papillomavirus (HPV). Papzimeos is a gene therapy that uses a virus to deliver a gene that helps the body's immune system attack and eliminate the virus causing the condition. The treatment has shown promising results in clinical trials, with patients experiencing long-lasting responses and improved quality of life.

Precigen, Inc. (Nasdaq: PGEN) announced significant long-term follow-up data for its gene therapy, PAPZIMEOS™ (zopapogene imadenovec-drba), at the American Academy of Otolaryngology–Head and Neck Surgery Foundation (AAO-HNSF) 2025 Annual Meeting. The data highlight the ongoing durability of complete responses in adults with recurrent respiratory papillomatosis (RRP) 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, the first and only FDA-approved therapy for RRP, demonstrated that 15 out of 18 complete responders (83%) maintained their responses over a median follow-up period of 36 months. This includes a median duration of complete response yet to be reached. The therapy showed a prolonged reduction in the requirement for surgical intervention to manage RRP, with 86% of patients experiencing a decrease in the number of surgeries in Year 1, 91% in Year 2, and 95% in Year 3 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 follow-up data reinforce the efficacy and safety profile of PAPZIMEOS. No new safety events were observed during the extended follow-up period, and the therapy was well-tolerated with no dose-limiting toxicities or treatment-related adverse events greater than Grade 2 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 updated durability data reinforce that PAPZIMEOS is not only a medical breakthrough but a transformative therapy for the RRP community," said Helen Sabzevari, PhD, President and CEO of Precigen. "For patients and their families, sustained responses mean freedom from the relentless cycle of repeat surgeries, reduction in the risk of surgical damage, and the possibility to improve quality of life. For physicians, it provides confidence in a safe and effective therapy that addresses the root cause of disease. And for the healthcare system, durable responses translate into fewer procedures, reduced complications, and lower long-term burden of care. This is precisely the type of impact we envisioned when we set out to develop what would become the first FDA-approved therapy for adults with RRP" 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, and potentially life-threatening disease caused by chronic HPV 6 or HPV 11 infection. It can lead 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 of the disease and can be associated with significant morbidity as well as significant patient and health system 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 express a fusion antigen comprising selected regions of human papillomavirus (HPV) types 6 and 11 proteins. It is designed to generate an immune response directed against HPV 6 and HPV 11 proteins in patients with RRP 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].

This latest announcement from Precigen underscores the potential of gene therapy in addressing difficult-to-treat diseases with high unmet patient need. The company's commitment to innovation and scientific breakthroughs from proof-of-concept through commercialization positions it well to continue advancing precision medicines in the future 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].