Daylight photodynamic therapy for actinic keratoses: a randomized double-blinded nonsponsored prospective study comparing 5-aminolaevulinic acid nanoemulsion (BF-200) with methyl-5-aminolaevulinate

Background Daylight-mediated photodynamic therapy (DL-PDT) using methyl-5-aminolaevulinate (MAL) is effective for thin, grade I, actinic keratoses (AK). There are no published studies of other photosensitizers used in DL-PDT. Objectives To compare the efficacy and adverse effects of 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) with MAL in DL-PDT of grade I-III AKs. Methods In 13 patients, 177 AKs were randomized symmetrically for a split-face prospective observer-blinded study and received either BF-200 ALA or MAL DL-PDT. Grade I AKs were treated once and grade II-III AKs twice with a 0.25-mm layer of photosensitizer precursors. Pain was assessed during and after the daylight exposure. Efficacy at 3 months was assessed clinically and histologically. Results BF-200 ALA cleared 71/84 (84.5%) and MAL 69/93 (74.2%) of the AKs (P = 0.099), all grades responding equally, but with new AKs appearing during follow-up (n = 4, BF-200 ALA; n = 8, MAL). In per patient half-face analysis BF-200 ALA showed significantly higher clearance rates for grade I AKs than did MAL (P = 0.027), but for thicker grades, clearance was equal (P = 0.564). BF-200 ALA and MAL treatments resulted in 61.5% and 38.5% complete histological clearance (P = 0.375), respectively. p53 expression decreased by 54.4% and 33.7%, respectively (P = 0.552). Both treatments were nearly painless with similar adverse reactions and no difference in patient preference. Conclusions BF-200 ALA showed a trend towards improved efficacy results compared with MAL. Thicker lesions in both groups responded when treated repeatedly. Importantly, a thin 0.25-mm layer of the photosensitizer precursors was sufficient, which may lead to lower expense.