Effective photodynamic therapy of actinic keratoses on the head and face with a novel, self-adhesive 5-aminolaevulinic acid patch.

BACKGROUND

Photodynamic therapy (PDT) is increasingly used for the treatment of actinic keratosis (AK).

OBJECTIVES

To investigate both the efficacy of different application times and the safety of a novel patch (PD P 506 A) containing aminolaevulinic acid in the PDT of mild to moderate AK.

METHODS

Applications of PD P 506 A for 0.5, 1, 2 and 4 h were compared in a multicentre, randomized, blinded-observer, parallel-group study. After patch removal, study lesions were illuminated with red light (lambda(em) approximately 630 nm; 37 J/cm(2)). Study lesions were not pretreated (e.g. by curettage) prior to PDT. Efficacy was evaluated 4 and 8 weeks after treatment. Safety and tolerability were determined through laboratory analyses and documentation of both local reactions and adverse events.

RESULTS

A total of 149 patients were initially enrolled. Of these, 140 patients (520 lesions) completed the study according to protocol. Eight weeks after treatment, 86% of the AK lesions (74% of the patients) treated with 4-h patch application showed complete clearance. The complete clearance rates of lesions (patients) for the 2-, 1- and 0.5-h treatment arms were 73% (47%), 72% (50%) and 51% (24%), respectively. Statistically, the 4-h application was identified as the 'best treatment'. Patients with clearance seemed to experience local reactions to a greater extent than patients without clearance. Local reactions to study treatments did not exceed the expected range.

CONCLUSIONS

The results of this first clinical efficacy study suggest excellent therapeutic outcomes with a single PD P 506 A PDT with a 4-h application.