Ipilimumab
Encyclopedia
Ipilimumab marketed as Yervoy, is a drug used for the treatment of melanoma
Melanoma
Melanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...

, a type of skin cancer. It is a U.S. Food and Drug Administration (FDA) approved human
Human
Humans are the only living species in the Homo genus...

 monoclonal antibody developed by Bristol-Myers Squibb
Bristol-Myers Squibb
Bristol-Myers Squibb , often referred to as BMS, is a pharmaceutical company, headquartered in New York City. The company was formed in 1989, following the merger of its predecessors Bristol-Myers and the Squibb Corporation...

, and works by activating the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

.

Additionally, ipilimumab is undergoing clinical trial
Clinical trial
Clinical trials are a set of procedures in medical research and drug development that are conducted to allow safety and efficacy data to be collected for health interventions...

s for the treatment of non-small cell lung carcinoma (NSCLC), small cell lung cancer (SCLC) and metastatic hormone-refractory prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...

.

Approvals and indications

Ipilimumab was approved by the FDA in March 2011 to treat patients with late-stage melanoma that has spread or cannot be removed by surgery.

Adverse effects

Ipilimumab treatment has been associated with severe and potentially fatal immunological adverse effects due to T cell activation and proliferation. Most of the serious adverse effects are associated with the gastro-intestinal tract; they include stomach pain, bloating, constipation or diarrhea, but also fever, breathing or urinating problems. A "risk evaluation and mitigation strategy" has been set up to inform prescribers of the potential risks.

Interactions

The combination of ipilimumab and leflunomide
Leflunomide
Leflunomide is a medication of the DMARD type, used in active moderate to severe rheumatoid arthritis and psoriatic arthritis. It is a pyrimidine synthesis inhibitor.-Basic chemical, pharmacological, and marketing data:...

 may lead to increased hepatotoxicity
Hepatotoxicity
Hepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...

. Over 90 other drug interactions are known, but none of them severe.

Mechanism of action

Ipilimumab is a fully human antibody that binds to CTLA-4
CTLA-4
CTLA4 also known as CD152 is a protein that plays an important regulatory role in the immune system...

 (cytotoxic T lymphocyte-associated antigen 4), a molecule on cytotoxic T lymphocytes that is believed to play a critical role in regulating natural immune responses. The absence or presence of CTLA-4 can augment or suppress the immune system's T-cell response in fighting disease.

Ipilimumab is designed to block the activity of CTLA-4, thereby sustaining an active immune response in its attack on cancer cells.

Clinical trials

, there are two fully human anti CTLA-4 monoclonal antibodies in advanced clinical trials. Ipilimumab, which is an IgG1 isotype, and tremelimumab
Tremelimumab
Tremelimumab is a fully human IgG2 monoclonal antibody produced by Pfizer. It binds to the protein CTLA-4, which is expressed on the surface of activated T lymphocytes...

 (from Pfizer) which is an IgG2 isotype.

Melanoma

On December 10, 2007, Bristol-Myers Squibb and Medarex released the results of three studies on ipilimumab for melanoma. The three studies tested 487 patients with advanced skin cancer. One of the three studies failed to meet its primary goal of shrinking tumors in at least 10.0% of the study's 155 patients. Side effects included rashes, diarrhea and hepatitis.

In 2010 a study was presented that showed a median survival of 10 months in advanced melanoma patients treated with ipilimumab, compared with 6 months for those treated with gp100
Gp100:209-217(210M)
Gp100:209-217 is a synthetic peptide cancer vaccine consisting of amino acid residues 209 through 217 of the glycoprotein 100 melanoma antigen, with a methionine substitution at position 210...

, an experimental vaccine (total n=676). Additionally, one year survival was 46% in those treated with only ipilimumab, compared with 25% in those treated with gp100, and 44% for those receiving both.
The Phase III clinical studies on the drug were controversial for their unconventional use of a control arm (as opposed to using a placebo or standard treatment). The study tested ipilimumab alone, ipilimumab with gp100, and the vaccine alone. Patients had a higher survival rate with ipilimumab alone, however it is not fully clear whether the vaccine caused toxicity, which would make the drug perform better by comparison. However it gained FDA approval in early 2011. In August 2011 it was approved for use in the UK.

Prostate cancer

, Medarex was performing a Phase I/II dose escalation clinical trial of ipilimumab in metastatic hormone-refractory prostate cancer (HRPC). , some of the patients with advanced prostate cancer had their tumors drastically shrink, promoting further trials.

On June 19, 2009, the Mayo Clinic reported two prostate cancer patients involved in a Phase II study using MDX-010 therapy who had been told initially that their condition was inoperable but had their tumors shrunk by the drug such that operation was possible and are now cancer-free as a result. This press report however was criticized as being somewhat inaccurate and entirely premature. The clinical trials were still at an early stage and were being run alongside other treatments – which could be the real explanation for the tumor shrinkage. It was far too early to say whether ipilimumab has made any difference at all.

Lung cancer

Medarex is running a Phase II trial of ipilimumab in addition to platinum-based chemotherapy (carboplatin
Carboplatin
Carboplatin, or cis-Diammineplatinum is a chemotherapy drug used against some forms of cancer...

) in patients with small cell and non-small cell lung cancer. It is scheduled to run from February 2008 to December 2011.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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