Dendreon‘s Provenge prostate cancer vaccine, the first in a new class of cancer treatments that use the patient’s own immune system, received FDA approval. The vaccine, approved for men with the advanced form of the disease, is designed to induce an immune response against prostatic acid phosphatase, an antigen expressed in most prostate cancers. Provenge (sipuleucel-T) belongs to a new therapeutic class called autologous cellular immunotherapies and could usher in an entirely new treatment paradigm for patients with cancer. Several other companies are developing immunotherapies targeting tumor antigens.