Targeted drugs may work in some cases when standard chemo drugs don’t. They also tend to have different side effects from standard chemo drugs for stomach cancer.
Chemotherapy (chemo) drugs target cells that divide rapidly, which is why they often work against cancer cells. But there are other aspects of cancer cells that make them different from normal cells. In recent years, researchers have developed new drugs to try to target these differences.
About 1 out of 5 of stomach cancers has too much of a growth-promoting protein called HER2 on the surface of the cancer cells. Tumors with increased levels of HER2 are called HER2-positive.
Trastuzumab (Herceptin) is a monoclonal antibody, a man-made version of a very specific immune system protein, which targets the HER2 protein. Giving trastuzumab with chemo can help some patients with advanced, HER2-positive stomach cancer live longer than giving chemo alone.
This drug only works if the cancer cells have too much HER2, so samples of your tumor must be tested to look for HER2 before starting treatment (see Tests for Stomach Cancer). It is not used in people whose cancer is HER2-negative.
Trastuzumab is injected into a vein (IV). For stomach cancer, it is given once every 2 or 3 weeks along with chemo. The best length of time to give it is not yet known.
The side effects of trastuzumab tend to be relatively mild. They can include fever and chills, weakness, nausea, vomiting, cough, diarrhea, and headache. These side effects occur less often after the first dose. This drug can also rarely lead to heart damage. The risk of heart damage is increased if trastuzumab is given with certain chemo drugs called anthracyclines, such as epirubicin (Ellence) or doxorubicin (Adriamycin).
For cancers to grow and spread, they need to create new blood vessels so that the tumors get blood and nutrients. One of the proteins that tells the body to make new blood vessels is called VEGF. VEGF binds to cell surface proteins called receptors to act. Ramucirumab (Cyramza®) is a monoclonal antibody that binds to a receptor for VEGF. This keeps VEGF from binding to the receptor and signaling the body to make more blood vessels. This can help slow or stop the growth and spread of cancer.
Ramucirumab is used to treat advanced stomach cancer, most often after another drug stops working.
This drug is given as infusion into a vein (IV) every 2 weeks.
The most common side effects of this drug are high blood pressure, headache, and diarrhea. Rare but possibly serious side effects include blood clots, severe bleeding, holes forming in the stomach or intestines (perforations), and problems with wound healing. If a hole forms in the stomach or intestine it can lead to severe infection and may require surgery to correct.
Other targeted drugs
Other targeted therapy drugs are being tested against stomach cancer. Some of these also focus on the HER2 protein, while others have different targets.