Targeted therapies are newer cancer treatments that target a gene or protein responsible for allowing cancer to grow. Targeted drugs work differently than standard chemotherapy drugs, which affect both cancer and normal cells. For this reason, targeted therapies often have different side effects, which may also be less severe. Targeted therapies are most often used in advanced and recurrent lung cancers, either alone or with chemotherapy.
Most targeted therapies are small molecule drugs or monoclonal antibodies (immune-system proteins produced in a laboratory from a single source). Current targeted therapies for lung cancer focus on stopping growth of blood vessels that nourish tumor cells (anti-angiogenesis drugs) or blocking specific enzymes and growth factor receptors involved in cancer cell proliferation (signal transduction inhibitors).
Anti-angiogenesis Drugs for Lung Cancer
Like all living things, tumors want to grow. In order to do so, they need nourishment. To get it, they form new blood vessels, a process called angiogenesis. In order to stop tumors from producing blood vessels, drugs are being created that target new vessels and prevent their growth, essentially starving the tumors so they cannot expand. This process is called anti-angiogenesis.
An example of an anti-angiogenesis drug is bevacizumab (Avastin)—a monoclonal antibody that targets vascular endothelial growth factor, a protein that helps new blood vessels form.
Signal Transduction Inhibitors for Lung Cancer
Epidermal growth factor receptor (EGFR) is a protein found on the surface of cells that helps them grow and divide. Some lung cancer cells have mutations in EGFR that make the cells abnormal and cause them to grow faster. Signal transduction inhibitors interfere with this.
Examples of signal transduction inhibitors include:
- Erlotinib (Tarceva), a drug that inhibits the tyrosine kinase activity of EGFR
- Gefitinib (Iressa), a drug that inhibits the tyrosine kinase activity of EGFR
- Crizotinib (Xalkori), a drug that inhibits the tyrosine kinase activity of a specific protein (ALK gene mutation)
- Ceritinib (Zycadia), a drug that inhibits the tyrosine kinase activity of a specific protein (ALK gene mutation)
Many more targeted therapies are being researched in clinical studies.
The side effects of targeted therapies vary greatly from person to person and depend on the type and dose of drugs given, how they are given, and the length of time they are given. Your treatment team can tell you about the side effects that are most common with your treatment.
Let your team know about any side effects you experience. They may be able to give you medicines to prevent or relieve side effects, suggest other ways to manage side effects, or change your targeted therapy or your treatment schedule. In some cases, the dose may need to be reduced or treatment may need to be delayed or stopped to prevent side effects from getting worse. For general advice, see the symptom management section.
The time it takes to get over some side effects and regain energy depends on many factors, including your overall health and your treatment.