HPV-associated CancerNCT04688476
An Extended Follow-Up Study of the HPV Vaccine Delayed Booster Trial
An observational study of HPV-associated Cancer, run by University of Arizona at 2 sites in United States.
Trial summary
This is an extended follow-up study to follow-up study participants who received 1 booster dose of Gardasil 9 in the "HPV vaccine delayed booster trial." This was a prospective, single-arm, open-label, non-randomized, phase IIa trial among 9-11 year-old girls and boys to determine the immunogenicity after a single… Read more about this study
- Who is it for?
- Any ageHealthy volunteers can take part
- Conditions the study is for
- HPV-associated Cancer
- How many people
- 113 participants
- Where
- 2 sitesUnited States
- Study dates
- 17 Nov 2020to Dec 2026
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: Study population is restricted to study participants who received one booster dose of Gardasil 9 at month 24 and elected not to receive the second booster at month 30 in the original "HPV vaccine delayed booster trial".
Who may be able to join
- Study participants who received one booster dose of Gardasil 9 at month 24 and elected not to receive the second booster at month 30 in the original "HPV vaccine delayed booster trial"
- Ability to understand and the willingness to sign a written informed consent document by the legal representative(s) of the participant.
- Ability to understand and the willingness to sign a written assent document by the participant.
Who cannot join
- Has received any HPV vaccine dose from an external source at any point during or after participation in the HPV vaccine delayed booster trial.
Trial locations and contacts
2 sites in 1 country.
United States2 sites
University of California, Los Angeles
Los Angeles, California, 90095
University of Arizona
Tucson, Arizona, 85724
About this study
This is an extended follow-up study to follow-up study participants who received 1 booster dose of Gardasil 9 in the "HPV vaccine delayed booster trial." This was a prospective, single-arm, open-label, non-randomized, phase IIa trial among 9-11 year-old girls and boys to determine the immunogenicity after a single dose of the nonavalent HPV vaccine (Gardasil 9) over 24 months, with a delayed booster dose at 24 months and an optional booster at 30 months after the first dose. Participants provided blood specimens at 6, 12, 18, 24, and 30 months after the first dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) were measured at each time point. One hundred and thirty-three (133) participants received one booster dose at month 24 and elected not to receive the second booster at month 30.
For this follow-up study, we anticipate that we will be able to accrue 120 participants from the original study who received just one booster dose. Participants who received one booster dose of Gardasil 9 will be contacted to return to the clinic to provide blood specimens at 48 (±3), 60 (±3), and 72 (±3) months after the priming dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) will be measured at each time point.
- Conditions
- HPV-associated Cancer
What is being measured
The primary outcome is the main question the study is designed to answer.
Stability of Geometric Mean Titer (GMT) of HPV16 Between 30 vs. 48 Months After the Priming Dose of Gardasil
HPV16 titer 48-to-30 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 48 months
Stability of Geometric Mean Titer (GMT) of HPV16 Between 48 vs. 60 Months After the Priming Dose of Gardasil
HPV16 titer 60-to-48 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 60 months
Stability of Geometric Mean Titer (GMT) of HPV16 Between 60 vs. 72 Months After the Priming Dose of Gardasil
HPV16 titer 72-to-60 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 72 months
Stability of Geometric Mean Titer (GMT) of HPV18 Between 30 vs. 48 Months After the Priming Dose of Gardasil
HPV18 titer 48-to-30 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 48 months
Stability of Geometric Mean Titer (GMT) of HPV18 Between 48 vs. 60 Months After the Priming Dose of Gardasil
HPV18 titer 60-to-48 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 60 months
Stability of Geometric Mean Titer (GMT) of HPV18 Between 60 vs. 72 Months After the Priming Dose of Gardasil
HPV18 titer 72-to-60 month ratio is calculated along with the lower bound of a 95% confidence interval
Measured: 72 months
Secondary outcomes (1)
The Differences in Geometric Mean Titer of Other HPV Types (HPV6/11/31/33/45/52/58) Between 30 vs. 48, 48 vs. 60, and 60 vs. 72 Months After the Priming Dose of Gardasil 9
Measured: 72 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Dec 2020
- Study start17 Nov 2020
- Primary completion9 Sep 2025
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for HPV-associated CancerStudies of the same condition, open and under way.
- More trials run by University of ArizonaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 113 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Arizona
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04688476
- Sponsor's protocol ID
- 2007882387
- Other IDs
- UG1 242596
- Status last verified
- Sep 2026
- First submitted
- 17 Dec 2020
- Last updated
- 9 Oct 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Extended Follow-Up Study of the HPV Vaccine Delayed Booster Trial
- ClinicalTrials.gov ID
- NCT04688476
- Acronym / sponsor ID
- 2007882387
- Conditions
- HPV-associated Cancer
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 113 participants (actual)
- Lead sponsor
- University of ArizonaUniversity, hospital or other
- Collaborators
- National Cancer Institute (NCI), University of California, Los Angeles
- Study start
- 17 Nov 2020 (actual)
- Primary completion
- 9 Sep 2025 (actual)
- Study completion
- Dec 2026 (estimated)
- First posted
- 30 Dec 2020 (actual)
- Results
- Posted 9 Oct 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is an extended follow-up study to follow-up study participants who received 1 booster dose of Gardasil 9 in the "HPV vaccine delayed booster trial." This was a prospective, single-arm, open-label, non-randomized, phase IIa trial among 9-11 year-old girls and boys to determine the immunogenicity after a single dose of the nonavalent HPV vaccine (Gardasil 9) over 24 months, with a delayed booster dose at 24 months and an optional booster at 30 months after the first dose. Participants provided blood specimens at 6, 12, 18, 24, and 30 months after the first dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) were measured at each time point. One hundred and thirty-three (133) participants received one booster dose at month 24 and elected not to receive the second booster at month 30.
For this follow-up study, we anticipate that we will be able to accrue 120 participants from the original study who received just one booster dose. Participants who received one booster dose of Gardasil 9 will be contacted to return to the clinic to provide blood specimens at 48 (±3), 60 (±3), and 72 (±3) months after the priming dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) will be measured at each time point.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Study population is restricted to study participants who received one booster dose of Gardasil 9 at month 24 and elected not to receive the second booster at month 30 in the original "HPV vaccine delayed booster trial".
Key inclusion criteria (3 listed)
- Study participants who received one booster dose of Gardasil 9 at month 24 and elected not to receive the second booster at month 30 in the original "HPV vaccine delayed booster trial"
- Ability to understand and the willingness to sign a written informed consent document by the legal representative(s) of the participant.
- Ability to understand and the willingness to sign a written assent document by the participant.
Key exclusion criteria (1 listed)
- Has received any HPV vaccine dose from an external source at any point during or after participation in the HPV vaccine delayed booster trial.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Stability of Geometric Mean Titer (GMT) of HPV16 Between 30 vs. 48 Months After the Priming Dose of Gardasil
Time frame: 48 months
HPV16 titer 48-to-30 month ratio is calculated along with the lower bound of a 95% confidence interval
Stability of Geometric Mean Titer (GMT) of HPV16 Between 48 vs. 60 Months After the Priming Dose of Gardasil
Time frame: 60 months
HPV16 titer 60-to-48 month ratio is calculated along with the lower bound of a 95% confidence interval
Stability of Geometric Mean Titer (GMT) of HPV16 Between 60 vs. 72 Months After the Priming Dose of Gardasil
Time frame: 72 months
HPV16 titer 72-to-60 month ratio is calculated along with the lower bound of a 95% confidence interval
Stability of Geometric Mean Titer (GMT) of HPV18 Between 30 vs. 48 Months After the Priming Dose of Gardasil
Time frame: 48 months
HPV18 titer 48-to-30 month ratio is calculated along with the lower bound of a 95% confidence interval
Stability of Geometric Mean Titer (GMT) of HPV18 Between 48 vs. 60 Months After the Priming Dose of Gardasil
Time frame: 60 months
HPV18 titer 60-to-48 month ratio is calculated along with the lower bound of a 95% confidence interval
Stability of Geometric Mean Titer (GMT) of HPV18 Between 60 vs. 72 Months After the Priming Dose of Gardasil
Time frame: 72 months
HPV18 titer 72-to-60 month ratio is calculated along with the lower bound of a 95% confidence interval
1 secondary outcome
The Differences in Geometric Mean Titer of Other HPV Types (HPV6/11/31/33/45/52/58) Between 30 vs. 48, 48 vs. 60, and 60 vs. 72 Months After the Priming Dose of Gardasil 9
Time frame: 72 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Oct 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of HPV-associated Cancer, run by University of Arizona at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 9 Oct 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Stability of Geometric Mean Titer (GMT) of HPV16 Between 30 vs. 48 Months After the Priming Dose of Gardasil (time frame: 48 months). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Oct 2026.