NEW YORK A recently discovered chemical in the sap of a weed common to North America and much of the world appeared safe and effective in treating patients with superficial and nodular basal cell carcinoma, according to results presented as a poster at the American Academy of Dermatology's Academy 2007 meeting.
Using the PEP-005 extract of the petty spurge plant (Euphorbia peplus), Dr. Robert H. Rosen, a dermatologist in private practice in Sydney, Australia, and his colleagues, with sponsorship from Peplin Ltd., the manufacturer of the extract, conducted two separate multicenter, randomized, controlled, double-blinded, parallel phase-IIa trials for treatment of superficial basal cell carcinoma (sBCC) and nodular basal cell carcinoma (nBCC).
They recruited 58 patients with nBCC and 60 with sBCC. All participants were white adult women with one basal cell carcinoma on the arm, shoulder, chest, face, neck, abdomen, back, leg, or scalp.
Patients were given a gel vehicle containing one of three concentrations of the drug: 0.0025%, 0.01%, and 0.05%. Each patient received two doses, either on 2 consecutive days or with the second dose 1 week after the first.
Application of the 0.05% concentration PEP005 topical gel overall showed the greatest efficacy in both types of BCC after 85 days, regardless of dosing schedule, Dr. Rosen and colleagues reported.
In the nBCC group, the two dosing schedules combined achieved complete histologic clearance of 25% of lesions (in 4 of 16 patients) and complete or marked clinical clearance (defined as 50%-90% improvement) in 38% of lesions (6 of 16 patients). For sBCC, the two regimens of 0.05% PEP005 achieved complete histologic clearance in 50% (8 of 16 patients) and complete or marked clinical clearance in 69% (11 of 16 patients).
There were no significant differences in safety between the dosing schedules. Among patients with nBCC, the most common local skin response was erythema, with 50% of the 0.05%-strength patients reporting moderate levels and 19% reporting severe erythema. Other responses reported for the 0.05% concentration were itch (moderate in 31% and severe in 0%), edema (31% moderate and 0% severe), scabbing/crusting (31% and 0%), and flaking/scaling/dryness (38% and 6%).
In the patients with sBCC, local skin reactions for the 0.05% PEP005 gel were itch (19% moderate and 0% severe), erythema (63% and 0%), edema (13% and 0%), scabbing/crusting (50% and 6%), flaking/scaling/dryness (25% and 13%), and moderate hypopigmentation (an adverse effect not reported in the nBCC group) in 13%.
The sap of petty spurge (Euphorbia peplus) has been used in traditional medicine as a cure for warts. ©