Artificial daylight photodynamic therapy using methyl aminolevulinate in a real-world setting in Germany - Results from the non-interventional study ArtLight.

Background: Artificial daylight photodynamic therapy (ADL-PDT) is an alternative, all-year applicable, nearly painless treatment approach for actinic keratoses (AK) with comparable effectiveness to daylight or conventional PDT. At the time this study was initiated, methyl aminolevulinate (MAL) was the only photosensitizer approved for ADL-PDT in Germany.

Objective: To gain comprehensive insights into the practicability of MAL-ADL-PDT in patients with AK using different artificial daylight sources under real-world conditions.

Methods: This prospective, non-interventional, multicenter study (ArtLight, NCT05725213) enrolled patients with Olsen grade 1 or 2 AK on the face and scalp in Germany. Patients were treated with MAL-ADL-PDT (160mg/g MAL cream). The primary outcome measure was the practicability of MAL-ADL-PDT assessed as rate of resolved AK lesions in the focus area (10x10 cm area within the treatment area). Secondary outcomes included treatment-associated pain (numeric rating scale, NRS-11), Actinic Keratosis Area and Severity Index (AKASI), total lesion count over time, skin preparation, safety, overall assessment of effectiveness, tolerability, adherence, and patient satisfaction.

Results: In total, 224 patients (median age: 75.0 years (range 50-91), 85.3% male, 62.5% AK Olsen grade 2, 55.4% treatment-naïve) were included and treated with MAL-ADL-PDT. Three months after treatment, lesion counts were reduced in the focus area by 71% (p<0.001) indicating practicability of the treatment. Nearly all patients (93.3%) experienced none or mild pain during PDT (NRS score 0-3). Median AKASI decreased from 6.2 at baseline to 3.4 at month 3 (95% CI 2.4-3.0; p<0.001). The majority of investigators (82.8%) and patients (80.0%) were satisfied with the treatment. No new safety signals were reported.

Conclusions: The clinical practicability of MAL-ADL-PDT was demonstrated under real-world conditions by effective lesion reduction and predominantly none to mild procedural pain. Thus, MAL-ADL-PDT is a convenient way for healthcare professionals to deliver PDT treatment to patients with AK located on the face and scalp.