Ipilimumab

Ipilimumab is approved by the Food and Drug Administration to treat melanoma.

A spot of melanoma.
A spot of melanoma.. Getty Images

Ipilimumab is approved by the Food and Drug Administration to treat melanoma. This is good news for patients, who long had few options once melanoma had spread to other areas of the body (stage IV disease).

What is Melanoma?

Melanoma, the most serious type of skin cancer, develops in the cells (melanocytes) that produce melanin — the pigment that gives your skin its color. Melanoma can also form in your eyes and, rarely, in internal organs, such as your intestines.

How Does Ipilumumab Work?

Ipilumumab is an antibody that activates the body's immune system to fight melanoma by inhibiting the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) molecule. CTLA-4 is a molecule on T-cells, a type of white blood cell that plays a critical role in regulating natural immune responses. The presence of CTLA-4 suppresses the immune system's response to disease, so blocking its activity stimulates the immune system to fight the melanoma.

The Evidence That Ipilumumab Works

Three phase II clinical trials have shown that treatment with ipilimumab results in a one-year survival rate of 47 to 51 percent for people with stage III or IV melanoma, which is almost double the average.

It is being tested in advanced (phase III) trials by itself and in combination with vaccines, other immunotherapies (such as interleukin-2), and chemotherapies (such as dacarbazine). Overall response rates range from 13 percent with ipilimumab plus vaccine in patients with stage IV disease to 17 and 22 percent with ipilimumab plus dacarbazine or interleukin-2, respectively, in patients with metastatic disease.

Responses have been long-lasting, and among those experiencing more severe side effects, even higher response rates have been seen (up to 36 percent). These results indicate that more than one-third of ipilimumab-treated patients with advanced melanoma experience a long-term survival benefit, a rare success story in the treatment of this disease.

Side Effects of Ipilumumab

Unlike chemotherapy, in which side effects become evident soon after beginning treatment, the side effects associated with ipilimumab can vary greatly, presumably because the human immune system varies from person to person.

The most common side effects of ipilimumab occur in the gastrointestinal tract (such as diarrhea and inflammation of the colon) and the skin (such as rash and inflammation of the skin). Less frequently occurring side effects include hepatitis, inflammation of the pituitary gland (hypophysitis), eye inflammation (uveitis), and kidney problems (nephritis). Side effects occur in up to 84 percent of patients but are generally mild and treatable.

Sources:

Hersh E, Weber J, Powderly J, et al (2009). Long-term survival of patients (pts) with advanced melanoma treated with ipilimumab with or without dacarbazine. J Clin Oncol 27:15s (suppl; abstr 9038).

Ledezma B (2009). Ipilimumab for advanced melanoma: A nursing perspective. Oncol Nurs Forum, 36(1), 97–104.

Mayo Clinic. Skin Cancer.

National Cancer Institute. Ipilimumab

Sarnaik AA, Weber JS (2009). Recent advances using anti-CTLA-4 for the treatment of melanoma. Cancer J. 2009 May-Jun;15(3):169-73.

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