The Food and Drug Administration (FDA) has approved Papzimeos™ (zopapogene imadenovec-drba) for the treatment of adults with recurrent respiratory papillomatosis (RRP).
Zopapogene imadenovec is a non-replicating adenoviral vector-based immunotherapy designed to induce an immune response against human papillomavirus (HPV) 6 and HPV 11 proteins in patients with RRP.
The approval was supported by data from an open-label, single-arm, phase 1/2 study (PRGN-2012-201; ClinicalTrials.gov Identifier: NCT04724980), which evaluated zopapogene imadenovec in 38 adults with histological and clinically diagnosed RRP who had at least 3 prior debulking procedures to remove laryngotracheal papillomas 12 months before initiating investigational treatment.
Study participants received zopapogene imadenovec subcutaneously on days 1, 15, 43, and 85 after undergoing a surgical debulking procedure to remove laryngotracheal papillomas. The primary endpoint was the percentage of patients with a complete response, defined as no requirement for surgical intervention in the 12 months after treatment.
Findings showed 51% (18/35) of patients who received the 5×1011 PU per injection dose of zopapogene imadenovec achieved a complete response at 12 months (95% CI, 34-69). Among these responders, 15 patients maintained a complete response through 24 months, demonstrating a 43% (15/35) complete response rate through 2 years.
Among the 3 patients who received the 1×1011 PU per injection dose, none achieved a complete response. This dose was not included in the efficacy evaluation.
The most common adverse reactions reported with zopapogene imadenovec were injection site reactions, fatigue, chills, pyrexia, myalgia and nausea. Additionally, thrombotic events may occur following administration of adenoviral vector-based therapies due to the potential to induce prothrombotic antibody development.
“For more than a century, since RRP was first recognized as a distinct disease, patients have had to rely on repeated surgeries to manage this relentless condition,” said Helen Sabzevari, PhD, President and CEO of Precigen. “With the landmark FDA approval of Papzimeos and broad label, all adult RRP patients are now eligible for access to the first and only approved therapy that targets the root cause of the disease.”
Papzimeos is supplied in a single-dose vial containing 5×1011 PU of zopapogene imadenovec in an extractable 1mL suspension. The vial should be stored frozen (≤ -76°F) until ready to thaw and administer.
The recommended dose is 5×1011 PU per injection administered subcutaneously 4 times over a 12-week interval. Surgical debulking of visible papilloma should be performed prior to the initial administration, and if present, prior to the third and fourth administration of Papzimeos to establish/maintain minimal residual disease.
This article originally appeared on MPR
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