Phase I Clinical Trial Using Topical Silicon Phthalocyanine (Pc 4) Photodynamic Therapy (PDT) for the Treatment of Pre-Malignant and Malignant Skin Conditions

OBJECTIVES:

• Determine the maximum tolerated dose of photodynamic therapy using topically delivered silicon phthalocyanine 4 in participants with actinic keratosis, Bowen's disease, squamous cell or basal cell skin cancer, or stage IA, IB, IIA, or IIB mycosis fungoides.
• Determine the safety and toxicity of this therapy with emphasis on whether it induces photosensitivity in non-treated sites in these participants .
• Determine the antitumor mechanism of this therapy, by monitoring tissue changes via clinical, histological, immunohistochemical, and other biochemical markers, in these participants.
• Determine, preliminarily, the dose of this therapy that results in highest clearing rates in these participants.

OUTLINE: This is a dose-escalation study.

Participants receive topical silicon phthalocyanine 4 (Pc 4). One hour later, participants undergo photodynamic therapy. Treatment repeats weekly for up to 3 weeks (up to 3 total treatments for the same lesion OR up to 3 lesions treated if multiple lesions are present).

Cohorts of 3 participants receive escalating doses of Pc 4 and visible light until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 1 of 3 participants experiences dose-limiting toxicity. Three additional participants are treated at the MTD.