Red Light PDT with 10% ALA Gel Demonstrates Efficacy for Superficial BCC

Red light photodynamic therapy (PDT) using 10% aminolevulinic acid (ALA) gel achieved robust clinical and histologic clearance in patients with superficial basal cell carcinoma (sBCC), according to results from a randomized, double-blind, vehicle-controlled Phase 3 study presented at the 2025 Fall Clinical Dermatology Conference.

The multicenter trial enrolled 187 participants with histologically confirmed sBCC, randomized 3:1 to receive two PDT sessions with either 10% ALA gel (n = 145) or vehicle (n = 42). Treatments were spaced 7 to 14 days apart, with each session involving up to 2g of gel applied under occlusion for 3 to 3.5 hours, followed by 10 minutes of red light exposure (635 nm, 37 J/cm²). Lesion clearance was evaluated at 12 weeks post-treatment, with histological assessment of target lesions (MTLs).

Results showed:

• 82.6% of lesions in the 10% ALA group achieved clinical lesion clearance vs 21.6% with vehicle,

• 83.4% of patients were flare-free after one or two PDT cycles,

• Composite participant clearance (clinical + histological) was 64.1% in the 10% ALA group vs 4.8% with vehicle (P < .0001).

Aesthetic outcomes were also favorable, with the majority of patients and investigators rating cosmetic results as “very good” or “good.” No new safety signals emerged; the most frequent treatment-related adverse events were transient application site reactions, including erythema, pain, and pruritus.

“These results support red light PDT with 10% ALA gel as a highly suitable non-surgical option for superficial BCC, particularly for multiple or large lesions in low-risk areas or when surgery is contraindicated,” the authors concluded.