Sutent (Sunitinib)

Sutent is a brand name targeted drug made by Pfizer and approved to treat two types of cancer. This is a newer kind of drug and is different from other types of drugs used in chemotherapy. It was designed to target certain enzymes in cancer cells and has been effective in treating certain cancers. It was first approved by the U.S. Food and Drug Administration (FDA) in 2006

Developed by Pfizer to target certain pathways in cancer cells, Sutent can cause some potentially serious side effects. However, some recent studies are showing that this drug may be able to help some patients struggling with mesothelioma. More research is needed to find out if there are biomarkers that can determine which patients would benefit from Sutent.

What is Sutent?

Sutent is a brand name drug with the generic name sunitinib. It was first approved by the FDA in 2006 and is approved to treat advanced renal cell cancers, pancreatic neuroendocrine tumors in patients who are not candidates for surgery, and gastrointestinal stromal tumors that have progressed and do not respond well to other treatments. Unlike other chemotherapy drugs, Sutent does not need to be injected intravenously. It is taken as an oral tablet, which is easier for patients. Like traditional chemotherapy, it is given in cycles, with time in between for the body to heal. Sutent is not approved for mesothelioma, but studies are underway to determine if it can be used as an effective treatment.

How it Works

Sutent is a type of drug called a receptor tyrosine kinase inhibitor. It targets several receptor tyrosine kinases, enzymes on the surface of cancer cells. These enzymes have been found to play an important role in how many types of cancers progress and develop. In targeting these cell surface enzymes, Sutent puts a halt to signaling inside the cell. Specifically it inhibits the formation of new blood vessels, which tumors need to grow, it inhibits the division of cancer cells, and it helps to trigger cell death in a tumor.

Some types of cancers are especially driven by receptor tyrosine kinases and this is why Sutent has been approved for a few very specific cancers. For mesothelioma patients, this is also the reason that Sutent may work for some and not for others. Mesothelioma is a complex cancer and is different in every individual. In some the receptor tyrosine kinases play a big role in how the cancer grows, while in others they do not. Researchers are still working on determining which patients can benefit from this targeted drug and therapy.

Side Effects

As with any drug, even these highly targeted drugs, there are bound to be side effects and adverse reactions. For Sutent, the most commonly reported side effects in patients are fatigue, weakness, fever, nausea, diarrhea, vomiting, high blood pressure, abdominal pain, peripheral edema, constipation, skin rashes, skin discoloration, skin dryness, back pain, changes in taste, cough, shortness of breath, anorexia, bleeding, and hand and foot syndrome. This last side effect is a condition caused by some chemotherapy drugs, which results in dry and cracked skin, stinging sensation, redness, swelling, thickening, and blistering on the palms of the hands and soles of the feet.

Black Box Warnings

The FDA reserves its strongest warning, the black box warning on a drug’s label, for the most serious side effects and complications that may be severe or life threatening. For Sutent, there is a black box warning about liver toxicity. The drug can cause significant damage to the liver, severe enough to be life threatening. Patients need to be carefully screened for liver enzymes before using this drug, and they should be screened while taking it. Some patients, those with a history of liver disease or damage or heavy alcohol use, may not be good candidates for the drug. Patients are told to watch for signs of liver damage, including yellowing eyes and skin, itchiness, dark urine, and pain in the upper right part of the abdomen.

Sutent and Mesothelioma

Sutent is not approved for treating mesothelioma, but researchers are looking into it as a possible treatment for this difficult cancer. The overall results have shown that some patients respond very well to it, while others do not. The reason is that it is a targeted drug and that the cancer can differ from one person to the next, so that this drug will effectively slow or stop tumor growth in some patients and not others. This is in contrast to traditional chemotherapy drugs which are not very targeted. They tend to work on any fast-growing cells, cancerous and otherwise.

Preliminary results from a phase II clinical trial with Sutent show that as a single agent, this drug may not be that useful in mesothelioma patients. Overall average survival time was just over eight months, which is not a great improvement over other treatments. However, there were some patients who responded very well to the treatment.

Other studies have been even more promising. One of these was a phase II clinical trial that involved 53 mesothelioma patients. All of the patients had previously undergone chemotherapy that did not slow the progression of the disease. In this study, 12 percent patients had a reduction in tumor size and 65 percent achieved stability. Only 22 percent of the patients continued to progress. The researchers also tried to determine if certain biomarkers could indicate which patients would respond well to Sutent, but were unsuccessful. The concluded that the drug should be continued to be used in mesothelioma patients, but that more work needs to be done to find the right biomarkers that will tell doctors which patients can benefit from treatment with Sutent.

Sutent is a new type of drug that is becoming more useful in the treatment of all kinds of cancers, including mesothelioma. These targeted drugs are making cancer treatment more individualized, which ultimately should make treatments more effective. Currently, Sutent is working for some mesothelioma patients, but not others. As researchers learn more about mesothelioma, they hope to find the biomarkers that will tell them which patients should be treated with Sutent for disease stability.