INO-3107 and the PAPZIMEOS precedent · INO-3107 · Dec 2024 – Aug 2025
How did PAPZIMEOS go from an accelerated-approval application to a traditional approval?
Precigen filed under accelerated approval. The FDA's review summary lists “converting the application from accelerated to traditional approval based on durability data” among the flexibilities it applied. Precigen says no confirmatory trial is now required.
EphemerisX Research · Published · 4 source documents · 1 min read
Short answer
The FDA converted it. Precigen submitted under the accelerated approval pathway; the FDA's review summary recommends traditional approval and lists, among the agency's flexibilities, converting the application from accelerated to traditional approval on the strength of durability data. Precigen's 10-K calls the result “full approval” and says a confirmatory trial is no longer required.
What the evidence shows
Precigen's 10-K: We completed submission of the rolling Biologics License Application (BLA) in December 2024 under an accelerated approval pathway; however, the FDA has granted Papzimeos full approval
10-K · Mar 25, 2026. The FDA had granted the application priority and rolling review
FDA · Aug 14, 2025 · p. 6.
The FDA's review summary: The review team recommends traditional approval for PAPZIMEOS for the treatment of adults with RRP
FDA · Aug 14, 2025 · p. 6. Among the flexibilities the agency lists: converting the application from accelerated to traditional approval based on durability data
FDA · Aug 14, 2025 · p. 18. The durability data are the 24-month results: a 24-month complete response rate of 43% (15/35; 95% CI 26% to 61%)
FDA · Aug 14, 2025 · p. 5.
The consequence, in Precigen's words: As a result of Papzimeos receiving full FDA approval, a confirmatory clinical trial is no longer required
10-K · Mar 25, 2026. The FDA's own description of its approach: the Agency exercised significant regulatory flexibility in the review of this BLA
FDA · Aug 14, 2025 · p. 6.
The license, in the FDA's approval letter of August 14, 2025: We are issuing Department of Health and Human Services U.S. License No. 2364 to Precigen, Inc., Germantown, Maryland, under the provisions of section 351(a) of the PHS Act
FDA · Aug 14, 2025 · p. 1.
The words differ by source: the FDA says “traditional”, Precigen “full”, and INOVIO's 10-K an unexpected traditional approval
10-K · Mar 12, 2026. What INOVIO said it meant: What did INOVIO say the PAPZIMEOS approval meant for INO-3107?
Follow the thread
- What evidence did the FDA accept when it approved PAPZIMEOS?“Significant regulatory flexibility”
- What did INOVIO say the PAPZIMEOS approval meant for INO-3107?“An unexpected traditional approval”
- Where does INO-3107's confirmatory trial stand in INOVIO's filings?No confirmatory trial required for PAPZIMEOS
- What is on the public record before the FDA's October 30, 2026 goal date for INO-3107?Accelerated converted to traditional
The documents, by date
The passages quoted
FDA approval letter, August 14, 2025 · page 1
We are issuing Department of Health and Human Services U.S. License No. 2364 to Precigen, Inc., Germantown, Maryland, under the provisions of section 351(a) of the PHS Act controlling the manufacture and sale of biological products.Open at the source →
FDA Summary Basis for Regulatory Action, August 14, 2025 · page 5
The primary endpoint, complete response (CR) rate at 12 months, defined as the percentage of subjects with no clinically indicated surgical interventions during the 12 months following treatment, was achieved in 51% of patients (18/35; 95% CI 34% to 69%). Furthermore, 15 patients maintained complete response at 2 years yielding a 24-month complete response rate of 43% (15/35; 95% CI 26% to 61%).Open at the source →
FDA Summary Basis for Regulatory Action, August 14, 2025 · page 6
Since the product received Breakthrough Therapy designation for the indication, the BLA was granted priority and rolling review.Open at the source →
FDA Summary Basis for Regulatory Action, August 14, 2025 · page 6
Acknowledging the rarity and serious life-threatening nature of RRP, the Agency exercised significant regulatory flexibility in the review of this BLA. The Agency incorporated patient perspectives to establish a novel endpoint which allowed a single pivotal study with change from baseline control design and small sample size to be considered as an adequate and well-controlled trial to support this BLA.Open at the source →
FDA Summary Basis for Regulatory Action, August 14, 2025 · page 6
The review team recommends traditional approval for PAPZIMEOS for the treatment of adults with RRP with one Post Marketing Requirement (PMR) related to virus-detection-related safety concerns during the zopapogene imadenovec-drba DS manufacturing process, three clinical Post Marketing Commitments (PMCs) related to additional evaluation of durability of treatment effect, viral shedding and pediatric extrapolationOpen at the source →
FDA Summary Basis for Regulatory Action, August 14, 2025 · page 18
converting the application from accelerated to traditional approval based on durability dataOpen at the source →
INOVIO Form 10-K, filed March 12, 2026
For RRP, Precigen received an unexpected traditional approval for PAPZIMEOS in August 2025 and launched the product commercially in the U.S. later in the year. As a result, we may be at a potential competitive disadvantage in this indication, if approved, as INO-3107 would be a second entrant.Open at the source →
Precigen Form 10-K, filed March 25, 2026
In August 2025, FDA granted full approval to Papzimeos for the treatment of adults with RRP. The Papzimeos approval marks a historic milestone for the RRP patient community as the first and only FDA-approved therapy for the treatment of adults with RRP. We completed submission of the rolling Biologics License Application (BLA) in December 2024 under an accelerated approval pathway; however, the FDA has granted Papzimeos full approval. As a result of Papzimeos receiving full FDA approval, a confirmatory clinical trial is no longer required.Open at the source →