Conditions: Multiple Actinic Keratoses
Allocation: RANDOMIZED | Intervention model: SINGLE_GROUP
Enrollment: 14
Healthy volunteers: no

Brief summary:
The aim of the study is to compare the efficacy of two photosensitizers, methyl-aminolaevulinate (MAL) and 5-aminolaevulinic nanoemulsion (BF-200 ALA) in the treatment of facial actinic keratosis. We use randomized, double-blinded prospective study design. The efficacy will be assessed clinically, histopathologically and immunohistochemically.

Detailed description:
Actinic keratoses (AKs) are superficial premalignant skin lesions that can progress into an invasive or metastatic squamous cell carcinoma. AKs can be treated with photodynamic therapy (PDT), of which cure rate compares to cryo surgery with an excellent cosmesis. In PDT the AK lesions are first curettaged, then a photosensitizer is applied on the skin and let to absorb for 3 hours. The skin is illuminated using a blue or red light source light source depending on the photosensitizer, which induces activation of protoporphyrin IX (PpIX) and phototoxic reaction destroying the cancer cells.

The approved photosensitizers in Europe are methyl-aminolevulinic acid cream, (MAL, Metvix™, Galderma), a patch containing 5-aminolevulinic acid (5-ALA, Alacare®, Spirig AG) and 5-aminolevulinic acid gel (BF-200 ALA, Ameluz®, Biofrontera AG) to be used with a red LED light (630-635 nm). In North America a 5-aminolevulinic acid stick (5-ALA, Levulan® Kerastick) can also be used with a blue light source (417 nm).

PpIX absorption peaks are within the visual spectrum of light, which allows PpIX daylight activation. During natural daylight PDT (NDL-PDT) protocol, PpIX is continuously activated during its development, whereas in conventional PDT (LED-PDT) using red LED lamps, large amounts of accumulated PpIX are momentarily activated.

Since skin field cancerization refers to presence of different degrees of visible and invisible dysplastic changes, the whole area should be treated to prevent the development of non-melanoma skin cancers (NMSCs). NDL-PDT enables treatment of field cancerization in one sitting whereas LED-PDT may need repeated illuminations to cover the whole area. NDL-PDT results in enhanced cost-efficacy due to reduced staff expenses, since there's no need for sensitizer absorption and illumination.

At the moment two photosensitizers have marketing authorization in Finland, ALA (Ameluz®) and MAL (Metvix™). We are piloting a study comparing the efficacy of these two light sensitizers in NDL-PDT. The efficacy of the treatments will be assessed clinically, histopathologically and immunohistochemically.

Arms:
arm 1: BF-200 ALA cream and MAL (Metvix, Galderma) used in a randomized split-face design

Interventions: intervention 1: BF-200 ALA cream intervention 2: MAL cream
Intervention descriptions: intervention 1: The symmetrical treatment areas will be randomized for treatments. First the treatment area will be wiped ethanol. Then sun protection factor (SPF) 20 cream will be applied on all sun-exposed areas of the skin. Then a 0,25mm layer application of Ameluz cream on the area. After appropriate absorption time of 30 minutes, the patients will be taken to the hospital balcony for 2 hour illumination with daylight to accomplish the phototoxic reaction. Maximum dosage will be 2 grams. The treatment will be repeated after 2 weeks for thicker gr II-III lesions with the same protocol. intervention 2: The symmetrical treatment areas will be randomized for treatments. First the treatment area will be wiped ethanol. Then SPF20 sun protection cream will be applied on all sun-exposed areas of the skin. Then a 0,25mm layer application of Metvix cream on the area. After appropriate absorption time of 30 minutes, the patientswill be taken to the hospital balcony for 2 hour illumination with daylight to accomplish the phototoxic reaction. Maximum dosage will be 2 grams. The treatment will be repeated after 2 weeks for thicker gr II-III lesions with the same protocol.

Protocol document: