Oncoprescribe Blog CRPC – A wave of new agents, but first Sipuleucel-T

This year 2 new agents have been approved for the treatment of Castrate-Resistant Prostate Cancer – Sipuleucel-T and Cabazitaxel. Sipuleucel-T is composed of autologous antigen-presenting cells (APC’s) from the patient, cultured with a fusion protein PA2024 (Prostate Acid Phosphatase-PAP linked to granulocyte/macrophage colony-stimulating factor). Prostatic Acid Phosphatase (PAP) is an antigen expressed in most prostate cancers. When administered, Sipuleucel-T an autologous active cellular immunotherapy stimulates T cell immunity against PAP and thus the prostate cancer cells. This agent demonstrated improvement in median survival and is best suited for those patients who are asymptomatic or have minimal symptoms with CRPC. It is important to note that this agent is given as three infusions 2 weeks apart and one may not see a drop in the PSA or improvement in the bone scan findings until after three months following treatment. For this reason it is best to consider this agent well before chemotherapy with docetaxel is planned. The number of patients who can be treated with this agent presently is limited due to various barriers associated with the processing of autologous Antigen Presenting Cells. It is important to realize that steroids may counter the T cell response associated with this agent and therefore should be avoided.