In a pivotal trial, 51% of adults with recurrent respiratory papillomatosis treated with Papzimeos required no surgeries for at least 12 months, with most maintaining response at 2 years.
Papzimeos is a non-replicating adenoviral vector–based immunotherapy engineered to elicit an immune response against papilloma cells expressing human papillomavirus (HPV) types 6 and 11, the etiologic agents in most recurrent respiratory papillomatosis (RRP) cases. The regimen consists of four subcutaneous injections over 12 weeks. Approval, which does not require a confirmatory trial, followed a rolling Biologics License Application completed in December 2024 under the accelerated pathway.
RRP is a rare condition affecting the upper and lower respiratory tract, characterized by recurrent benign tumors that may cause dysphonia, airway obstruction, and post-obstructive pneumonia. Standard management has relied on repeated surgical debulking, which does not eradicate underlying HPV infection and may lead to cumulative laryngeal injury. An estimated 27,000 US adults are affected, with some undergoing numerous procedures annually.
Efficacy and safety were demonstrated in an open-label, single-arm pivotal trial conducted at the National Institutes of Health in 35 adults with RRP. Complete response, defined as no surgical intervention in the 12 months following treatment, was achieved in 18 patients (51%). Of these, 15 maintained responses at 24 months. Treatment was well tolerated, with no dose-limiting toxicities or treatment-related adverse events exceeding grade 2.
Responders exhibited greater HPV-specific T-cell expansion than non-responders. Trial results were presented at the 2024 American Society of Clinical Oncology annual meeting and published in The Lancet Respiratory Medicine.
According to Precigen, the manufacturer, Papzimeos represents a targeted approach that addresses the underlying viral cause rather than symptom control alone. The company has initiated commercial distribution and established Papzimeos SUPPORT, a patient services program offering insurance navigation, financial assistance, and access coordination.
Source: Precigen
