Actinic keratoses (AK) may appear in all sun-exposed skin areas; however, the lesions occurring outside the head area shows typically more resistant to treatment than those on the face.

A recent phase III study determined the efficacy and safety of BF-200 ALA versus vehicle for treating mild-to-severe AK found on extremities, trunk and neck with red light photodynamic therapy (PDT). Fifty patients from the 6 centers in Germany were enrolled in this study with each one receiving a maximum of 2 field-directed PDTs. 

Clinical endpoints and 1-year follow-up results were documented. The results obtained were as follows:

• BF-200 ALA was found to be superior to the vehicle regarding total lesion clearance rates (86.0% vs. 32.9%) and patient complete clearance per patient′s side (67.3% vs. 12.2%). 
• One-year overall lesion recurrence rate was found to be 14.1% versus 27.4% in BF-200 ALA versus vehicle, respectively. 
• Patients were more satisfied with the cosmetic outcome of BF-200 ALA/PDT comparing vehicle/PDT. 
• Adverse events were the same as the known safety profile of BF-200 ALA/PDT.

Thus BF-200 ALA causes significantly higher AK clearance rates on extremities, trunk and neck contrasting the vehicle, along with good tolerance.