Controlled Study of the Occurrence of Actinic Keratosis on the Face After Cryotherapy + Aminolevulinic Acid (ALA) Photodynamic Therapy

Inclusion Criteria:

- Four to fifteen AKs on the face

- histologically confirmed presence of abnormal architecture and satellite atypical
keratinocytes in the epidermis, in clinically normal tissue samples of photodamaged
skin adjacent to AKs

- at least one previously treated nonmelanoma skin cancer (NMSC) on the head and/or neck
area within the past five years

Exclusion Criteria:

- Pregnancy

- history of cutaneous photosensitization, porphyria, hypersensitivity to porphyrins or
photodermatosis

- lesions suspicious for skin cancer (skin cancer not ruled out by biopsy) or untreated
skin cancers within the Treatment Area

- skin pathology or condition which could interfere with the evaluation of the test
product or requires the use of interfering topical or systemic therapy

- Subject is immunosuppressed

- unsuccessful outcome from previous ALA-PDT therapy

- currently enrolled in an investigational drug or device study

- has received an investigational drug or been treated with an investigational device
within 30 days prior to the initiation of treatment

- known sensitivity to one or more of the vehicle components (ethyl alcohol, isopropyl
alcohol, laureth 4, polyethylene glycol)

- has an active herpes simplex infection OR a history of 2 or more outbreaks within the
past 12 months, on the face

- use of the following topical preparations on the extremity to be treated:

- Keratolytics including urea (greater than 5%), alpha hydroxyacids [e.g.glycolic
acid, lactic acid, etc. greater than 5%], salicylic acid (greater than 2%) within
2 days

- Retinoids, including tazarotene, adapalene, tretinoin, within 4 weeks

- Microdermabrasion, laser ablative treatments, ALA-PDT, chemical peels,
5-fluorouracil (5-FU), diclofenac, ingenol mebutate, imiquimod or other topical
treatments for AK within 8 weeks

- use of systemic retinoid therapy within 6 months