Trial Information

A Multicenter, Double Blind, Vehicle-controlled, Randomized Study of Photodynamic Therapy (PDT) With Metvix 160 mg/g Cream and Aktilite CL128 LED Light in Patients With Multiple Actinic Keratosis on the Face and/or Scalp

Actinic keratoses are pre-malignant skin lesions, which may develop to squamous cell
carcinomas (SCC). They are usually small, thin, erythematous, de-squamating lesions on light
exposed atrophic skin and the lesions are often multiple.

Photodynamic therapy (PDT) is the selective destruction of abnormal cells through light
activation of a photosensitiser in the presence of oxygen. These cells accumulate more
photosensitiser than normal cells. The photosensitiser generates reactive oxygen species
upon illumination.

For skin diseases, such as actinic keratosis (AK), there has been an increasing interest in
using topically applied precursors of the photoactive porphyrins (PAP). The most commonly
used precursors have been 5-aminolevulinic acid (ALA) and its derivatives. The present test
drug contains methyl aminolevulinate, which penetrates the lesions well and shows high
lesion selectivity.

Different light sources (i.e. CureLight, Aktilite CL16 and Aktilite CL128) have been used
for the activation of PAP, which absorbs light in the range of 400-700 nm. The present study
uses the Aktilite CL 128 lamp. Aktilite 128 is based on LED technology and emits a narrow
red light spectrum with an average wavelength of 630 (+/-5) nm. This study is similar to two
other studies performed, on which the U.S. approval of Metvixia® cream is based except for
the light source used. This study is one of two studies performed to document the safety and
efficacy of the Aktilite CL 128 lamp when used in combination with Metvixia® cream.

Previous studies have shown that the risks attributed to Metvixia® PDT are few and related
mainly to transient pain and local erythema during and shortly after treatment. These
reactions are part of the expected local phototoxicity reaction. PDT offers an advantage to
other treatment modalities for actinic keratosis, being a non-invasive treatment available
on an outpatient basis. Several separate lesions can be treated simultaneously and the same
lesion(s) can be treated repeatedly with success. There are no known systemic toxicity or
interaction with other medication. The treatment is also lesion selective, leaving the
surrounding tissue intact and functional, also allowing excellent cosmetic results after
treatment.