Long-term (6 and 12 months) follow-up of two prospective, randomized, controlled phase III trials of photodynamic therapy with BF-200 ALA and methyl aminolaevulinate for the treatment of actinic keratosis

Actinic keratosis (AK) is defined as squamous cell carcinoma (SCC) in situ.1,2 It represents the most common neoplasia affecting fair-skinned subjects in sun-exposed body areas such as the face and scalp. AKs may progress to SCC, therefore necessitating treatment.3,4 As photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA), or its derivative methyl aminolaevulinate (MAL), combines high efficacy with an excellent cosmetic outcome, it is recommended as one of the first-line treatments in this indication.1 Formulations containing ALA have frequently been used clinically, but are often restrained by their short-term stability and poor skin penetration. BF-200 ALA is a new nanoemulsion-based gel formulation containing 7·8% ALA (10% ALA hydrochloride), which overcomes these drawbacks, displaying an improved stability of ALA in the aqueous formulation and an enhanced penetration into the epidermis.5 Based on these advantages, lower ALA concentrations are sufficient for an excellent therapeutic outcome, which was recently demonstrated in two phase III studies of the treatment of AK, one of them in comparison to a registered MAL formulation.6,7 Here we present the recurrence rates of subjects treated with BF-200 ALA or MAL PDT in two phase III trials and the percentage of patients who were totally cleared of AK 12 months after PDT. Safety issues such as new lesions and skin cancer in the treatment area are also reported.