Precigen Secures FDA Approval For PAPZIMEOS And Redefines RRP Treatment

By Erin Harris, Editor-In-Chief, Cell & Gene
Follow Me On Twitter @ErinHarris_1

As Chief Editor of Cell & Gene, I’ve had the privilege of interviewing countless innovators in cell and gene therapy, but every so often, I encounter a story that feels like a true turning point for the field. My recent conversation with Helen Sabzevari, Ph.D., President and CEO of Precigen, was one of those moments.

In July 2025, the FDA approved PAPZIMEOS (zopapogene imadenovec-drba), the first-ever therapy for adults living with recurrent respiratory papillomatosis (RRP). For more than a century, patients with this chronic disease have endured repeated surgeries to remove papillomas caused by HPV infection only to see them grow back. PAPZIMEOS changes that cycle, offering patients durable relief and, for some, freedom from surgery altogether.

PAPZIMEOS earned full FDA approval without requiring a confirmatory trial, following a rolling BLA submission under the accelerated pathway. When Dr. Sabzevari and I spoke, it was clear this milestone wasn’t just a victory for Precigen; it was a victory for patients, families and caregivers, and the field at large.

Navigating the Regulatory Pathway for PAPZIMEOS

Dr. Sabzevari explained that from day one, the company worked together with the FDA to design a pivotal trial built around a prospectively defined, clinically meaningful endpoint. That foresight, paired with Breakthrough Therapy and Orphan Drug designations, gave PAPZIMEOS a clear path forward. The result was a journey from IND to approval in just four and a half years.

She shared that the regulatory success came from pairing each pipeline asset with the disease indication most likely to benefit. For PAPZIMEOS, that meant starting with RRP, where the unmet need is immense and the potential for patient impact is immediate.

Results That Speak for Themselves

The clinical results are extraordinary. In the pivotal trial, 51% of patients achieved a complete response, requiring no surgeries for at least 12 months after treatment. Many have maintained that response out to 24 months, and some for 36 months. To put this in perspective, these patients had undergone a median of 40 lifetime surgeries before enrolling in the study. Most needed three to ten surgeries in the year before treatment.

“Every surgery carries risk of irreversible damage,” Dr. Sabzevari, “PAPZIMEOS offers patients a chance at long-term disease control by addressing the root cause of RRP, HPV 6 and 11 infections. That restores not only health but also normalcy.”

Safety, Mechanism, and Validation

Another point Dr. Sabzevari emphasized was safety. PAPZIMEOS demonstrated a favorable safety profile with no dose-limiting toxicities and no treatment-related adverse events beyond Grade 2. Importantly, the therapy elicited strong HPV 6/11-specific T-cell responses in responders, which is clear evidence that the immune system was being retrained to fight the underlying virus.

She explained that this trial didn’t just validate PAPZIMEOS, it validated the AdenoVerse® platform, which Precigen designed to activate targeted immune responses safely across multiple diseases. This was one of the most forward-looking aspects of our conversation: PAPZIMEOS is not just a therapy, it’s a proof point for an entire technology platform.

Commercialization With Patients at the Center

Approvals, of course, are only the beginning. I asked Dr. Sabzevari about the commercialization plan, and her response reinforced Precigen’s patient-first philosophy. The company launched Papzimeos SUPPORT, a program designed to help patients navigate insurance, access financial assistance, and connect with care teams. “Commercialization has to be patient-centered,” she said. “Our goal is to shoulder the complexity, so patients and providers don’t have to.”

Looking Beyond RRP

We discussed next steps, and she shared that Precigen is already planning to study PAPZIMEOS in pediatric patients and expand access globally. Beyond RRP, they see potential in other HPV-driven diseases, including genital warts and HPV-associated cancers such as cervical and head and neck cancers.

PAPZIMEOS is both a breakthrough treatment and a stepping stone. Its success opens the door for other therapies built on the AdenoVerse platform, therapies that may redefine standards of care across viral-driven diseases.

For patients, PAPZIMEOS offers hope where none existed before. For physicians, it provides a new tool beyond the operating room. For the field, it demonstrates that with smart science, strategic regulatory engagement, and a relentless focus on patients, transformative therapies can move from concept to clinic faster than ever before. “For over a century, surgery was the only option,” she said. “Today, patients have access to a therapy that activates their own immune system against HPV 6 and 11, delivering durable responses with a favorable safety profile.”