Actinic KeratosesPhase 4NCT06461442
Efficacy and Safety of Cryotherapy Versus 5-Fluorouracil in the Treatment of Actinic Keratosis
A Phase 4 study testing Cryotherapy and 5Fluorouracil in people with Actinic Keratoses, run by University of California, Davis at 1 site in United States.
Trial summary
The goal of this clinical trial is to compare the effectiveness and safety of two treatments-cryotherapy and 5-Fluorouracil (5-FU)-for actinic keratosis, a common skin condition caused by long-term sun exposure. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Actinic Keratoses
- What is being tested?
- Cryotherapy and 5Fluorouracil
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 73 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2024to 1 Sep 2026
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 18 years of age or older
- Has a clinical diagnosis of 10 or more AKs in the head, neck, or extremities areas
- Able to give informed consent themselves
- Willing to return for follow up visits
Who cannot join
- Cognitively Impaired
- Incarcerated
- Non-English speakers
- Immuno-comprised status
- Received any kind of treatment for AK within the past 2 months
- Use of systemic retinoids within the past 3 months
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- Suspicion of cancer in the target area
- Porphyria
- Genetic skin cancer disorders
- Allergy to trial drugs or peanut/soy products
- Pregnancy or breast-feeding
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
University of California, Davis - Dermatology Department
Sacramento, California, 95816
About this study
Official title: Efficacy and Safety of Cryotherapy Versus 5-Fluorouracil in the Treatment of Actinic Keratosis: A Prospective, Randomized Controlled, Intra-Individual Trial
The goal of this clinical trial is to compare the effectiveness and safety of two treatments-cryotherapy and 5-Fluorouracil (5-FU)-for actinic keratosis, a common skin condition caused by long-term sun exposure. Cryotherapy is a treatment that uses extreme cold produced by liquid nitrogen to freeze and destroy abnormal cells, and 5-FU is a topical cream applied to the skin to treat lesions by interfering with cell growth. The main questions this trial aims to answer are:
- Which treatment, cryotherapy or 5-FU, is more effective in reducing the number of actinic keratosis lesions?
- What are the side effects associated with each treatment?
- How do these treatments impact patient satisfaction, cosmetic outcomes, and health-related quality of life?
Read more
Participants will:
- Undergo a baseline assessment where their demographics information such as age, sex, race, smoking status, and medical history are recorded, along with the number and severity of actinic keratosis lesions.
- Receive both cryotherapy and 5-FU, with each treatment applied to different areas of their body. The area of the body to receive each treatment is decided by a random process (like flipping a coin).
- Complete weekly surveys to monitor for side effects during and after the treatment period.
- Return to the clinic for follow-up assessments at 3 months and 12 months.
- Conditions
- Actinic Keratoses
- Being tested
- Cryotherapy, 5Fluorouracil
- Keywords
- cryotherapy, 5-Fluorouracil
- Medical subject headings
- Keratosis, Actinic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CryotherapyProcedure or surgery
Extremely cold liquid (liquid nitrogen) will used by a dermatologist to freeze and destroy abnormal cells in the treatment areas randomized to this treatment.
5FluorouracilDrug
Patients will apply 5% 5-Fluorouracil cream in a thin layer twice daily for 4 weeks on the treatment areas randomized to this treatment.
| Study group | Role | What they receive |
|---|---|---|
| Cryotherapy and 5-Fluoruracil | Experimental | Each actinic keratosis lesion, or treatment area, will be randomly assigned to receive either cryotherapy or 5-fluoruracil treatment. Receives: Procedure: Cryotherapy; Drug: 5Fluorouracil |
What is being measured
The primary outcome is the main question the study is designed to answer.
Partial clearance rate
Proportion of patients with at least a 75% reduction in the number of baseline AK lesions within the selected treatment area
Measured: 3 months and 12 months
Secondary outcomes (7)
Complete clearance rate
Proportion of patients with no clinically visible AK lesions (i.e., a 100% reduction in the number of baseline AK lesions) within the selected treatment area
Measured: 3 months and 12 months
Percent reduction of AK lesions
Decrease in number AK lesions from baseline within the selected treatment area
Measured: 3 months and 12 months
Rate of progression to keratinocyte carcinoma
Proportion of AK lesions within the treatment area that progress to keratinocyte carcinoma
Measured: 3 months and 12 months
Recurrence rate
Proportion of participants with recurrent or new lesions within the treatment area
Measured: 3 months and 12 months
Patient satisfaction
Proportion of patients who would choose the same treatment again and if they would recommend it to others
Measured: 3 months and 12 months
Health-Related Quality of Life
Skindex-29 questionnaire
Measured: 3 months and 12 months
Cosmetic outcome
The cosmetic outcome will be evaluated using a 4-point scale (1 = excellent, 2 = good, 3 = moderate, and 4 = poor) by an investigator who is blinded to the treatment allocation
Measured: 3 months and 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Jun 2024
- Study start1 Jul 2024
- Primary completion1 Sep 2026 (estimated)
- Study completion1 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Actinic KeratosesStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe 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
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 73 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Daniel Eisen, MD, Principal investigator, UC Davis Department of Dermatology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06461442
- Sponsor's protocol ID
- 2164169
- Status last verified
- Jul 2026
- First submitted
- 10 Jun 2024
- Last updated
- 6 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Jansen MHE, Kessels JPHM, Nelemans PJ, Kouloubis N, Arits AHMM, van Pelt HPA, Quaedvlieg PJF, Essers BAB, Steijlen PM, Kelleners-Smeets NWJ, Mosterd K. Randomized Trial of Four Treatment Approaches for Actinic Keratosis. N Engl J Med. 2019 Mar 7;380(10):935-946. doi: 10.1056/NEJMoa1811850.
PubMed 30855743
Study at a glance
From the registry record, last updated by the sponsor on 6 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy and Safety of Cryotherapy Versus 5-Fluorouracil in the Treatment of Actinic Keratosis: A Prospective, Randomized Controlled, Intra-Individual Trial
- ClinicalTrials.gov ID
- NCT06461442
- Acronym / sponsor ID
- 2164169
- Conditions
- Actinic Keratoses
- Keywords
- cryotherapy, 5-Fluorouracil
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 73 participants (estimated)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 1 Jul 2024 (actual)
- Primary completion
- 1 Sep 2026 (estimated)
- Study completion
- 1 Sep 2026 (estimated)
- First posted
- 17 Jun 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to compare the effectiveness and safety of two treatments-cryotherapy and 5-Fluorouracil (5-FU)-for actinic keratosis, a common skin condition caused by long-term sun exposure. Cryotherapy is a treatment that uses extreme cold produced by liquid nitrogen to freeze and destroy abnormal cells, and 5-FU is a topical cream applied to the skin to treat lesions by interfering with cell growth. The main questions this trial aims to answer are:
- Which treatment, cryotherapy or 5-FU, is more effective in reducing the number of actinic keratosis lesions?
- What are the side effects associated with each treatment?
- How do these treatments impact patient satisfaction, cosmetic outcomes, and health-related quality of life?
Participants will:
- Undergo a baseline assessment where their demographics information such as age, sex, race, smoking status, and medical history are recorded, along with the number and severity of actinic keratosis lesions.
- Receive both cryotherapy and 5-FU, with each treatment applied to different areas of their body. The area of the body to receive each treatment is decided by a random process (like flipping a coin).
- Complete weekly surveys to monitor for side effects during and after the treatment period.
- Return to the clinic for follow-up assessments at 3 months and 12 months.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cryotherapy and 5-Fluoruracil | Experimental | Procedure: Cryotherapy, Drug: 5FluorouracilEach actinic keratosis lesion, or treatment area, will be randomly assigned to receive either cryotherapy or 5-fluoruracil treatment. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 18 years of age or older
- Has a clinical diagnosis of 10 or more AKs in the head, neck, or extremities areas
- Able to give informed consent themselves
- Willing to return for follow up visits
Key exclusion criteria (11 listed)
- Cognitively Impaired
- Incarcerated
- Non-English speakers
- Immuno-comprised status
- Received any kind of treatment for AK within the past 2 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CryotherapyExtremely cold liquid (liquid nitrogen) will used by a dermatologist to freeze and destroy abnormal cells in the treatment areas randomized to this treatment. | Procedure or surgery | Cryotherapy and 5-Fluoruracil |
| 5FluorouracilPatients will apply 5% 5-Fluorouracil cream in a thin layer twice daily for 4 weeks on the treatment areas randomized to this treatment. | Drug | Cryotherapy and 5-Fluoruracil |
Primary outcome
Partial clearance rate
Time frame: 3 months and 12 months
Proportion of patients with at least a 75% reduction in the number of baseline AK lesions within the selected treatment area
7 secondary outcomes
Complete clearance rate
Time frame: 3 months and 12 months
Percent reduction of AK lesions
Time frame: 3 months and 12 months
Rate of progression to keratinocyte carcinoma
Time frame: 3 months and 12 months
Recurrence rate
Time frame: 3 months and 12 months
Patient satisfaction
Time frame: 3 months and 12 months
Health-Related Quality of Life
Time frame: 3 months and 12 months
Cosmetic outcome
Time frame: 3 months and 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Jul 2026.
- Background: PubMed 30855743Jansen MHE, Kessels JPHM, Nelemans PJ, Kouloubis N, Arits AHMM, van Pelt HPA, Quaedvlieg PJF, Essers BAB, Steijlen PM, Kelleners-Smeets NWJ, Mosterd K. Randomized Trial of Four Treatment Approaches for Actinic Keratosis. N Engl J Med. 2019 Mar 7;380(10):935-946. doi: 10.1056/NEJMoa1811850.
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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.
Daniel Eisen, MD principal investigator
UC Davis Department of Dermatology
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Cryotherapy and 5Fluorouracil in people with Actinic Keratoses, run by University of California, Davis at 1 site 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 4 inclusion and 11 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: enrolling by invitation, as of the sponsor's last update on 6 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
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?
Partial clearance rate (time frame: 3 months and 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06461442, which also lists 1 linked publication.
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 6 Jul 2026.