Lasting Efficacy of Red-Light Photodynamic Therapy With 10% Aminolevulinic Acid Gel for Superficial Basal Cell Carcinoma: 1-Year Follow-Up of a Randomized, Vehicle-Controlled, Double-Blind, Multicenter Phase III Study

Introduction: Surgical excision remains the primary treatment for superficial basal cell carcinoma (sBCC), while non-invasive alternatives that can be fully administered by healthcare professionals (HCPs) remain limited. Red light photodynamic therapy (PDT) with 10% aminolevulinic acid (ALA) gel previously demonstrated strong efficacy and safety for sBCC in a randomized, double-blind, vehicle-controlled Phase III trial. This report extends those findings through 12 months of follow-up to characterize the durability of lesion clearance and cosmetic outcome. Methods: Adult participants with at least one treatment-naïve, histologically confirmed sBCC received up to 2 PDT cycles (2 PDT sessions per cycle, administered 7–14 days apart). Either 10% ALA gel (Ameluz®) or vehicle was applied to the lesions and incubated under occlusion for 3 to 3.5 hours, followed by illumination with BF-RhodoLED® (10 min, 635 nm, 37 J/cm²). After the treatment phase, one sBCC per participant —the main target lesion (MTL)— was excised for histological assessment. Additional target lesions were not excised, and recurrences were instead determined via clinical (or visual) inspection. Because MTLs were already excised for histological assessment, the analysis of recurrence rates was based on the initially cleared additional target lesions only. Results: 182 participants are analyzed for safety. 17 participants (21 lesions) in the 10% ALA arm and 2 participants (2 lesions) in the vehicle arm were analyzed for recurrence at 12-months. Participant and lesion recurrence rates were < 12.0% for 10% ALA gel, and 50% for vehicle. The participant-based probability of initial and sustained clearance was 57.4% with 10% ALA gel and 2.4% with vehicle. The lesion-based probability was 75.6% with 10% ALA gel and 11.0% with vehicle. Cosmetic outcomes remained favorable at 12 months, and no treatment-related adverse events were reported during the follow-up period. Conclusion: Twelve-month outcomes confirm that red light PDT with 10% ALA gel provides durable lesion clearance and sustained cosmetic benefits in sBCC, supporting its role as a clinically viable and favorable non-invasive, office-based therapeutic option.