The U.S. Food and Drug Administration granted approval for Papzimeos (zopapogene imadenovec-drba), marking the introduction of a first-of-its-kind, non-replicating adenoviral vector-based immunotherapy for adult patients with recurrent respiratory papillomatosis (RRP).
Recurrent respiratory papillomatosis is a rare, chronic condition caused by persistent infection with human papillomavirus (HPV) types 6 or 11, resulting in the growth of benign tumors in the respiratory tract, most commonly in the larynx. This disease imposes substantial challenges on patients, including voice alterations, breathing difficulties, and airway obstruction. To date, no approved medical therapies exist that eliminate the necessity for repeated surgical interventions.
“Randomized trials are not always needed to approve medical products and this approval is proof of that philosophy,” stated Vinay Prasad, M.D., M.P.H., Director of the FDA’s Center for Biologics Evaluation and Research (CBER). “The FDA will always demand the correct clinical study for the specific medical product and disease. Our requirements for products given to tens of millions of healthy people will be different than products given to at most hundreds or thousands of patients with unique diseases.”
With approximately 1,000 new cases diagnosed each year in the United States, RRP represents a rare disease with significant unmet medical need. Until this approval, no therapies had been approved for RRP. Papzimeos is delivered through subcutaneous injections and is designed to trigger an immune response targeting cells infected with HPV types 6 and 11, the underlying cause of RRP. This therapy introduces a novel mechanism of action, which is different from conventional approaches that largely on repeated surgical procedures.
“This approval has the potential to transform the treatment landscape for RRP and offer lasting relief for patients who previously faced repeated surgeries to control symptoms of their disease,” commented Vijay Kumar, M.D., Acting Director of the Office of Therapeutic Products in CBER.
Data Supporting Papzimeos
The FDA approved Papzimeos after the decision was supported by data from a single-arm, open-label trial assessing Papzimeos in adult patients with RRP requiring three or more surgeries annually. Patients underwent four subcutaneous administrations of Papzimeos within 12 weeks after surgical debulking (reduction) therapies.
For the study, 51.4% (18/35) of patients attained a complete response, defined as no surgical requirement for 12 months after treatment. Clinical follow-up data indicated that long-term responses were sustained in the majority of patients for a period of two years with a significant correlation between clinical activity and induction of HPV 6/11-specific T cells.
The safety profile of Papzimeos was favorable, with the majority of treatment-emergent adverse events being mild to moderate. No dose-limiting toxicities were observed, and no treatment-related serious adverse events occurred.
The FDA approved Papzimeos under Priority Review and was granted both Orphan Drug designation and Breakthrough Therapy designation. The FDA granted approval of Papzimeos to Precigen, Inc.
