Sipuleucel-T [APC8015], is a therapeutic cancer vaccine for prostate cancer. It has been approved by the FDA on April 29, 2010 as an autologous cellular immunotherapy for the treatment of asymptomatic or minimally symptomatic metastatic castrate resistant (hormone refractory) prostate cancer. It is made by Dendereon corporation by name of provenge.
The therapy is prepared specifically for each patient.
It has been found to extend survival by about 4 months in advanced metastatic cancer of prostate.
Mechanism of Action of Sipuleucel-T and Details of Treatment Method
Sipuleucel- T is an immunostimulant. Therapy with sipuleucel – T is an autologous cellular immunotherapy.
There are three basic steps in treatment of patients with this drug.
- A patient’s own white blood cells, primarily antigen-presenting cells, also called Dendritic cells, are extracted by leukapheresis procedure. Leukapheresis is a procedure in which white blood cells are separated from a sample of blood.
- The blood product is sent to the factory and incubated with a fusion protein (PA2024) consisting of two parts, the antigen prostatic acid phosphatase (PAP), which is present in 95% of prostate cancer cells, and an immune signaling factor granulocyte-macrophage colony stimulating factor (GM-CSF) that helps the APCs to mature.
- The activated blood product (APC8015) is returned from the factory to the infusion center and re-infused into the patient to cause an immune response against cancer cells carrying the PAP antigen.
For complete treatment with sipuleucel-T, three courses are rrepeated with two weeks between successive courses
Use of Sipuleucel-T
Sipuleucel-T is used to treat people with metastatic, asymptomatic, hormone-refractory prostate cancer, also called metastatic castrate-resistant (mCRPC) or androgen independent prostate cancer
This stage is lethal stage in prostate cancer.
Repeated double blind trials have shown overall survival benefit to patients in three double-blind randomized phase III clinical trials,
Earliest trial was the IMPACT trial, which incidentally also served as the basis for licensing approval of sipuleucel-T. This trial found that median survival of patient prolonged 4 months thought there was no reduction in tumor size.
After that, other trials have also documented the results.
Side Effects of Sipuleucel-T
The most common side effects include:
- Pain in the bladder
- Bloating [Swelling of the face, arms, hands, lower legs, or feet]
- Bloody or cloudy urine
- Body aches
- Chest pain
- Burning or painful urination
- Breathing difficulty
- Double vision
- Inability to move the arms, legs, or facial muscles