Patients with a common form of skin cancer called basal cell carcinoma (BCC) may soon have a new treatment option after researchers announced that a Phase II clinical trial of an experimental drug called vismodegib showed strongly positive results. Although there are a number of treatment options available for BCC, the most common type of skin cancer, most involve removing the cancer surgically, which can cause scarring. In some patients with large tumors on the face, surgery is not an appropriate treatment option because of the risk of severe disfiguration.
Vismodegib is an oral drug that inhibits the cancer-signaling pathway Hedgehog by targeting a protein called Smoothened. In BCC and other cancers, the Hedgehog signaling pathway becomes abnormally activated, which results in tumor growth and the growth of blood vessels that feed the tumor, called angiogenesis. Vismodegib is being developed in collaboration between the drug companies Genentech and Curis.
The Phase II study of vismodegib involved 104 patients with either locally advanced (laBCC) or metastatic (mBCC) basal cell carcinoma. The patients received 150 mg of vismodegib orally once a day until their cancer got worse. The overall response rate (patients with tumor shrinkage) assessed by independent reviewers was 43% in the laBCC group and 30% in the mBCC group. The clinical benefit rate, which included both patients who responded to the drug or had their tumors stop growing, was about 75% in both arms. Vismodegib is currently being evaluated in other cancer clinical trials, including one in operable BCC and another in metastatic pancreatic cancer.