In short
5-aminolevulinic acid is a light-activated medicine used to treat certain skin conditions, including actinic keratosis and basal cell carcinoma. It is also used during surgery to help visualise some tumours. One clinical trial is currently authorised to study a gel form of this substance in 120 people with weakened immune systems who have premalignant or malignant skin lesions.
Key points
- 5-aminolevulinic acid is a light-activated medicine used to treat actinic keratosis and basal cell carcinoma.
- One authorised trial is studying Ameluz 78 mg/g gel in 120 immunosuppressed patients with skin lesions.
- The trial is a low intervention study comparing photodynamic therapy in immunosuppressed and non-immunosuppressed people.
- The main outcome is complete clearance of lesions at 3 months.
- The medicine is also used as a diagnostic tool to help surgeons see certain tumours during operations.
- Known brand names include Ameluz, Levulan Kerastick, and Gleolan.
What is 5-aminolevulinic acid?
5-aminolevulinic acid is a light-activated medicine, also known as a photosensitiser. It belongs to the drug class of topical photochemotherapeutics when applied to the skin, and to malignancy photosensitisers when given systemically. The substance is available under several brand names: Ameluz and Levulan Kerastick as topical products, and Gleolan as a systemic product. In the United Kingdom, medicines containing 5-aminolevulinic acid hydrochloride include Ameluz 78 mg/g gel and Gliolan 30 mg/ml powder for oral solution.
How does 5-aminolevulinic acid work?
5-aminolevulinic acid is a substance that makes certain cells sensitive to light. When applied to the skin or given systemically, it is taken up by abnormal cells and converted into a light-sensitive compound. When those cells are then exposed to light of a specific wavelength, the compound becomes active and damages the abnormal cells. This process is called photodynamic therapy, or PDT. The same principle is used in photodynamic diagnosis, where the light-sensitive compound helps surgeons see abnormal tissue during operations, as shown in a study of peritoneal metastases in biliary tract cancer in mice.
Which conditions is it used or studied for?
- Actinic keratosis — a rough, scaly patch on the skin caused by years of sun exposure, which can sometimes develop into skin cancer.
- Basal cell carcinoma — a common type of skin cancer that grows slowly and rarely spreads to other parts of the body.
- Cutaneous squamous cell carcinoma — a type of skin cancer that can grow more quickly than basal cell carcinoma and may spread if not treated.
- Diagnosis and investigation — as a systemic product, it is used to help visualise certain tumours during surgery.
How is 5-aminolevulinic acid given?
5-aminolevulinic acid is available in different forms. As a topical medicine, it comes as a gel (Ameluz 78 mg/g gel) or as a solution applied with an applicator (Levulan Kerastick). As a systemic medicine, it is available as a powder for oral solution (Gliolan 30 mg/ml). In the clinical trial described below, the gel form is applied directly to the skin lesions.
What do the clinical trials show?
One clinical trial is currently authorised in the EU Clinical Trials Information System. The study investigates photodynamic therapy with BF-200 ALA, the active substance in Ameluz gel, in people with weakened immune systems who have grade I–II actinic keratosis and superficial basal cell carcinoma.
The trial is a low intervention study with 120 planned participants. It compares immunosuppressed patients with non-immunosuppressed patients. The main outcome measure is the complete clearance rate of lesions at 3 months, defined as the complete clinical disappearance of the treated lesion.
The trial is currently in the authorised status, meaning it has received regulatory approval to proceed but may not yet be recruiting participants.
What side effects are known?
The supplementary sources provided do not contain specific information about side effects of 5-aminolevulinic acid. The clinical trial record does not list side effect data, as the study has not yet reported results.