Long-term follow-up of a randomized, double-blind, phase III, multi-centre study to evaluate the safety and efficacy of field-directed photodynamic therapy (PDT) of mild to moderate actinic keratosis using BF-200 ALA versus placebo and the BF-RhodoLED® lamp.

BACKGROUND

In actinic keratosis (AK), field cancerization describes areas of skin where multiple visible AK lesions are surrounded by healthy looking skin containing non-visible (subclinical) lesions. As all AK lesions have a risk of progression to cutaneous squamous cell carcinoma, experts advise field-directed treatment. Photodynamic therapy (PDT) is an effective field-directed treatment option for AK; however, long-term efficacy data are still scarce.

OBJECTIVES

This publication presents follow-up data of a phase III study evaluating the efficacy and safety of field-directed PDT.

METHODS

The study was conducted in seven centres in Germany. For PDT, participants with AKs on the face and scalp (treatment area of 20 cm) had received up to two field-directed PDTs using BF-200 ALA or placebo, and illumination with narrow-spectrum red light. Only participants or lesions with complete response 12 weeks after the last PDT were assessed for recurrences. The treatment area was evaluated 6 and 12 months after the last PDT for recurrence, cosmetic outcome and new lesions.

RESULTS

Fifty-four participants in the BF-200 ALA and 30 in the placebo group entered the follow-up. The probability of a participant to be initially completely cleared and to remain cleared for 12 months was 57.4% for BF-200 ALA versus 20.0% for placebo. The probability of a lesion to be initially cleared and remain cleared for 12 months was 85.4% for BF-200 ALA versus 31.5% for placebo. 83.3% of participants with cosmetic impairment at baseline rated the cosmetic outcome 12 months after PDT with BF-200 ALA as very good or good. All parameters of skin quality further improved during follow-up.

CONCLUSIONS

We showed that effectiveness of field-directed PDT with BF-200 ALA and narrow-spectrum red light was maintained during follow-up. Based on our results, field-directed PDT is a beneficial long-lasting treatment for AK patients.

CLINICAL TRIAL REGISTRATION NUMBERS

2013-002510-12 (EudraCT); NCT01966120 (Clinicaltrials.gov).