Targeted therapy for eye cancer

Targeted therapy uses drugs to target specific molecules (such as proteins) on cancer cells or inside them. These molecules help send signals that tell cells to grow or divide. By targeting these molecules, the drugs stop the growth and spread of cancer cells and limit harm to normal cells. Targeted therapy may also be called molecular targeted therapy.

Targeted therapy isn’t used very often to treat eye cancer. If you do have it, it may be to:

• manage side effects of radiation therapy
• treat some types of advanced eye cancer that have grown outside of the eyeball (called extraocular extension)
• treat eye cancer that doesn’t respond to other treatments or comes back (recurs) after treatment
• relieve pain or control the symptoms of metastatic eye cancer (called palliative therapy)

If you have targeted therapy, your healthcare team will use what they know about the cancer and about your health to plan the drugs, doses and schedules.

Monoclonal antibodies have been designed in a lab to recognize and lock onto particular protein markers on the surface of some eye cancer cells.

Bevacizumab (Avastin and biosimilars) and ranibizumab (Lucentis and biosimilars) are monoclonal antibodies that target vascular endothelial growth factor (VEGF), a protein involved in the growth of blood vessels. They can be used to shrink blood vessels. You may have bevacizumab or ranibizumab to treat damage to the retina and vision loss caused by radiation (called radiation retinopathy). They are given through a needle into the eye (intraocular injection).

Rituximab (Rituxan and biosimilars) is a monoclonal antibody that targets the CD20 protein. It is sometimes used to treat lymphoma of the eye. Rituximab may be given on its own or with chemotherapy drugs such as methotrexate and CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone). It is given through a needle into a vein (intravenous, or IV) or into the eye.

Yttrium-90 (Y-90) ibritumomab tiuxetan( Zevalin) is a drug used in radioimmunotherapy (RIT). It is made of a monoclonal antibody (ibritumomab) that binds to the CD20 protein. The radioactive version of yttrium (yttrium-90 or Y-90) is attached to the monoclonal antibody in order to deliver radiation therapy directly to the cells the antibody binds to. Very few people will have RIT with yttrium-90 ibritumomab tiuxetan to treat lymphoma of the eye. It is given by IV.

BRAF inhibitors are drugs that block the BRAF protein, which sends signals inside the cell to control cell growth. A mutation in the BRAF gene (called BRAF V600E) can be found in some types of eye cancer. Cancer cells that have changes to this gene are called BRAF V600E positive (BRAF V600E+).

MEK inhibitors are drugs that control the growth of eye cancer by blocking the mitogen-activated protein kinase (MEK) protein. Since the MEK protein is normally turned on (activated) by the BRAF protein, MEK inhibitors are another way to treat metastatic eye cancers with BRAF gene mutations.

Trametinib (Mekinist) is a MEK inhibitor that is sometimes used for metastatic melanoma of the eye. It may be given with the BRAF inhibitor dabrafenib (Tafinlar). Both are given as a pill taken by mouth.

Side effects of targeted therapy will depend mainly on the type of drug or combination of drugs, the dose, how it’s given and your overall health. Tell your healthcare team if you have side effects that you think are from targeted therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Talk to your doctor or pharmacist about what side effects to expect.

Find out more about targeted therapy. To make the decisions that are right for you, ask your healthcare team questions about targeted therapy.

Details on specific drugs change regularly. Find out more about sources of drug information and where to get details on specific drugs.