A Phase II Study of Photodynamic Therapy With LEVULAN® Topical Solution + Blue Light Versus LEVULAN® Topical Solution Vehicle + Blue Light Using Spot and Broad Area Application and Incubation Times of 1, 2 and 3 Hours for the Treatment of Multiple Actinic Keratoses on the Face or Scalp

Inclusion Criteria:

- 6-20 Grade 1/2 AKs on the face or scalp

- a history of AK therapy within the treatment area at least twice in the two years
prior to study entry

Exclusion Criteria:

- Pregnancy

- Grade 3 AKs or atypical AKs (e.g., AK > 1 cm2 in size) within the Treatment Area

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

- plans to be exposed to artificial tanning devices or excessive sunlight during the
trial

- Subject is immunosuppressed

- unsuccessful outcome from previous ALA-PDT therapy

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

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

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

- any condition which would make it unsafe for the subject to participate in this
research study

- 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)

- Subject has;

- an active herpes simplex infection OR

- a history of 2 or more outbreaks within the past 12 months, in the Treatment
Area

- use of the following topical preparations on the extremities 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 of initiation of treatment.

- Cryotherapy within 2 weeks of initiation of treatment

- Retinoids, including tazarotene, adapalene, tretinoin, retinol, within 4 weeks
of initiation of treatment.

- Microdermabrasion, laser ablative treatments, ALA-PDT, chemical peels, 5-FU,
diclofenac, imiquimod or other topical treatments for AK within 8 weeks of
initiation of treatment.

- Two or more ALA PDT treatments in the past 6 months

- use of systemic retinoid therapy within 6 months of initiation of treatment.