A Phase 3 interventional study of Zopapogene imadenovec-drba in Recurrent Respiratory Papillomatosis (RRP), Juvenile-onset Recurrent Respiratory Papillomatosis and Papillomavirus Infections, sponsored by Precigen, Inc. Not yet recruiting at 1 site in United States. Open to participants aged 1 Year to 17 Years. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Precigen, Inc · Phase 3, Interventional, and Treatment
Recurrent respiratory papillomatosis (RRP) is a rare disease in which wart-like growths caused by human papillomavirus (HPV) types 6 or 11 form in the airway. These growths can affect the voice and breathing and often come back after they are removed, meaning many children will need repeated surgeries to keep their airway open. There is no medicine approved to treat RRP in children.
This study is testing zopapogene imadenovec, an investigational immunotherapy designed to help the immune system recognize and control cells infected with HPV 6 and 11. Zopapogene imadenovec is approved in the United States for the treatment of adults with recurrent respiratory papillomatosis.
All participants in this study will receive zopapogene imadenovec; there is no placebo group. The study drug is given as four injections under the skin over about three months. Before the first injection, participants have a standard surgical procedure to remove visible growths. Participants are then followed for at least 12 months to see how many need further surgery, and are contacted periodically for up to five years after their last injection.
The study will enroll children in two age groups, starting with older children and opening to younger children only after safety has been reviewed.
31 studies on the registry are indexed under Recurrent respiratory papillomatosis; 9 are open to participants now.
This study's planned enrollment of 15 is below the median of 24 across 22 interventional studies indexed under Recurrent respiratory papillomatosis.
Browse Recurrent respiratory papillomatosis studies →Precigen, Inc is the lead sponsor of 6 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Key Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive four subcutaneous administrations of zopapogene imadenovec on Day 1, Week 2, Week 6, and Week 12, each in a different limb. Participants aged ≥6 to \<18 years receive 5 x 10\^11 particle units per injection; participants aged ≥1 to ≤5 years begin at 2.5 x 10\^11 particle units per injection with sentinel dosing. All participants undergo a standard-of-care debulking procedure on Day -1.
Biological: Zopapogene imadenovec-drba
Zopapogene imadenovec
Complete response rate
Percentage of participants with a complete response, defined as no requirement for any clinically indicated debulking intervention during the 12 months following the last administration of zopapogene imadenovec.
Time frame: 12 months following last administration of study drug
Number of participants with adverse events (AEs) and treatment-related AEs
Incidence and severity of all AEs and of AEs assessed as related to zopapogene imadenovec, graded by NCI CTCAE version 6.0.
Time frame: From first administration through 12 months after the last administration (treatment-related AEs through 28 days after the last administration)
Time to first clinically indicated debulking intervention (duration of response)
Interval from completion of zopapogene imadenovec treatment until the first clinically indicated debulking intervention, estimated by the Kaplan-Meier method.
Time frame: From the last administration (Week 12) up to 5 years
Objective response rate (ORR)
Percentage of participants with a complete response or a partial response. Partial response is defined as at least a 50% decrease in the number of clinically indicated debulking interventions during the 12 months after treatment compared with the 12 months before treatment.
Time frame: 12 months before the first administration and 12 months after the last administration
Plan to share: Undecided
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Zopapogene imadenovec
Recurrent respiratory papillomatosis →
Precigen, Inc