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Study on the Effectiveness and Safety of Metformin and Methyl Aminolevulinate in Daylight Therapy for Actinic Keratosis Patients

Registered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the treatment of actinic keratoses, which are rough, scaly patches on the skin caused by sun exposure. The study will evaluate the effectiveness and safety of a treatment involving topical metformin, a medication commonly used to manage blood sugar levels, but in this case, it is applied to the skin. The trial will also use daylight photodynamic therapy (dPDT) with methyl aminolevulinate hydrochloride, a light-activated treatment that helps to remove damaged skin cells.

The purpose of the study is to determine if using topical metformin alongside daylight photodynamic therapy can improve the treatment of actinic keratoses. Participants will receive the treatment for 12 weeks and will be monitored for an additional 36 weeks to observe the treatment's effects and any potential side effects. The study will include a comparison with a placebo, which is a substance with no active medication, to better understand the treatment's effectiveness.

Throughout the study, participants will apply the topical treatments to their skin, and the effects will be observed over time. The goal is to find out if this combination of treatments can effectively reduce the number of actinic keratoses and improve the condition of the skin. This research aims to provide new insights into managing skin lesions caused by sun damage.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed. Participants must be over 18 years old and have at least 5 actinic keratoses on the face or scalp. Women of childbearing potential must use effective contraception.

  2. Step 2

    Treatment phase

    The treatment involves the application of topical metformin and methyl aminolevulinate as part of daylight photodynamic therapy. This phase lasts for 12 weeks.

    The medications are applied topically, meaning they are placed directly on the skin where the actinic keratoses are located.

  3. Step 3

    Observation phase

    After completing the 12-week treatment, there is a 36-week observation period. During this time, the effectiveness of the treatment and any side effects are monitored.

Who can join the trial?

3 criteria

  • Males or females over 18 years of age.
  • Subjects with at least 5 actinic keratoses on the face and/or scalp. Actinic keratoses are rough, scaly patches on the skin caused by sun exposure.
  • If women of childbearing capacity participate, they must use an effective method of contraception throughout the study. Contraception refers to methods used to prevent pregnancy.

Who cannot join the trial?

4 criteria

  • Patients who are not within the specified age range for the study.
  • Patients who have medical conditions other than actinic keratoses, which are rough, scaly patches on the skin caused by sun exposure.
  • Patients who are part of a vulnerable population, meaning they may need special protection or care.
  • Patients who do not meet other specific health criteria set by the study.
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Investigated drugs

  • Metformin

    This medication is being tested in a topical form, meaning it is applied directly to the skin. In this trial, it is used as an additional treatment to enhance the effects of another therapy. Metformin is commonly known for its use in managing blood sugar levels in diabetes, but in this study, it is being evaluated for its potential benefits in treating skin conditions.

  • Methyl Aminolevulinate (MAL)

    This is a substance used in a type of treatment called photodynamic therapy. It is applied to the skin and then activated by light, which helps to treat certain skin conditions. In this trial, it is used in combination with daylight to treat actinic keratoses, which are rough, scaly patches on the skin caused by sun damage.

What is already known about the treatment

Metformin (Topical) – This medication is applied directly to the skin and is currently being studied in clinical trials for its effectiveness and safety as an additional treatment to daylight photodynamic therapy in managing actinic keratoses. Actinic keratoses are rough, scaly patches on the skin caused by sun exposure, and they can potentially lead to skin cancer. The main therapeutic indication for topical metformin in this context is to enhance the treatment of these skin lesions. At the molecular level, metformin is believed to work by affecting cellular energy processes, which may help in reducing abnormal cell growth. It is classified pharmacologically as a biguanide, commonly known for its use in diabetes management, but here it is being explored for dermatological purposes.

Investigated diseases

Actinic Keratoses – Actinic keratoses are rough, scaly patches on the skin that develop from years of exposure to the sun. They are most commonly found on the face, lips, ears, back of the hands, forearms, scalp, or neck. These patches are usually small, ranging from the size of a pinhead to about an inch in diameter. The skin may become discolored, appearing pink, red, or brown, and can feel dry or like sandpaper. Over time, actinic keratoses can become more pronounced and may develop into a more serious skin condition if left untreated. They are considered a precursor to skin cancer, particularly squamous cell carcinoma.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-520798-38-00Protocol codeICI21/00031Estimated enrolment135 patientsSponsorFundacion Instituto De Investigacion Sanitaria Aragon

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).