490 Samcyprone (diphenylcyclopropenone ointment) for the treatment of common warts

Abstract

Diphenylcyclopropenone (DPCP) is a potent topical immunotherapy agent that has been used in a compounded form since the late 1970s by physicians for the treatment of common warts, alopecia areata, and cutaneous metastases of melanoma. Although not approved by the FDA or EMA, physicians continue to use compounded DPCP because of its proven effects in these dermatologic conditions. The use of the drug as reported in the literature is not standardized and widely varying strengths have been suggested for the sensitization and challenge treatments with DPCP, resulting in inconsistent results from a safety and efficacy viewpoint. RXi Pharmaceuticals has developed a proprietary ointment formulation of DPCP called Samcyprone that consists of a low sensitization (0.4% DPCP) dose followed by a standardized weekly treatment dose (0.04% DPCP) regimen. Cutaneous warts are benign epidermal tumors caused by human papillomaviruses (HPVs). A phase 2a clinical study was conducted evaluating Samcyprone (DPCP Sensitization and Treatment Ointments) for the treatment of common warts. The study was a multi-center, multi-dose trial conducted in subjects with at least one cutaneous, plantar or periungual wart present for at least four weeks. In this trial, subjects were first treated with a sensitization dose on the inner arm and on one or more preselected wart lesions. Once the sensitization response was confirmed, subjects continued with weekly treatments for 10 weeks. Wart clearance was evaluated based on the Investigators Global Assessment Score (IGAS) and wart measurements over time during the treatment period. Immunotherapeutic Skin Response Scores were also collected as a safety assessment of local reactions to be expected from a topical immunomodulator. Results show that while a sensitization reaction is a prerequisite for therapeutic response, the level of the reaction is not necessarily predicting the impact on wart clearance.