Skip to content
    Font Size

    FDA OKs Provenge for Prostate Cancer Therapy

    'Vaccine' Is an Immune Therapy That Treats Advanced Prostate Cancer

    How Provenge Works

    Once a cancer grows beyond a certain point, the immune system has a hard time fighting it. One reason is that cancer cells look a lot to the immune system like normal cells. Another reason is that tumors may give off signals that manipulate the immune system into leaving them alone.

    Provenge bypasses these problems. The treatment first removes a quantity of dendritic cells from a patient's blood. Dendritic cells are antigen-presenting cells -- that is, they show pieces of an offending microbe or tumor to immune cells, priming them to attack cells that carry those pieces (antigens).

    The patient's doctor ships the cells to Dendreon, which then exposes them to Provenge. Provenge is a molecule made inside genetically engineered insect cells. The molecule marries prostatic acid phosphatase (PAP) -- a marker found on nearly all prostate cancer cells -- to an immune-stimulating factor called GM-CSF.

    Once these cells have been exposed to the Provenge molecule, they're shipped back to the doctor who infuses them back into the patient. This is done three times in one month. The first infusion primes the immune system. The second and third doses spur an anticancer immune response.

    The treatment is not without side effects. Nearly all patients suffer some mild to moderate adverse reactions such as chills, fatigue, fever, back pain, nausea, joint ache, and headache.

    But so far, Provenge has been remarkably safe. However, clinical trials suggested the treatment might be linked to a slightly increased risk of stroke. Treated patients will be closely monitored to see if this risk is real.

    1 | 2

    Today on WebMD

    man with doctor
    Symptoms, risks, treatments
    man coughing
    Men shouldn’t ignore
    prostate cancer cells
    What does this diagnosis mean?
    doctor and male patient
    Is it worth it?
    cancer fighting foods
    15 Cancer Symptoms Men Ignore
    Prostate Enlarged
    Picture Of The Prostate
    Prostate Cancer Quiz
    screening tests for men
    Prostate Cancer Symptoms
    Vitamin D