Targeted molecular therapy is a type of personalized medical therapy designed to treat cancer by interrupting unique molecular abnormalities that drive cancer growth. The drugs used in targeted therapy are designed to interfere with a specific biochemical pathway central to the development, growth, and spread of that particular cancer.
Targeted molecular therapy is personalized to meet each person’s individual needs because cancer develops differently in everyone. In some cancers the molecular targets are known but in others the targets are still being identified. In some cases, the same types of cancer have different molecular targets. Identifying the molecular targets in any given patient's cancer requires working closely with pathologists to carefully identify the correct cancer pathology.
Targeted molecular therapy provides medical oncologists a better way to customize cancer treatment. Advantages of molecular targeted therapy include:
- Potentially less harm to normal cells
- Potentially fewer side effects
- Improved effectiveness
- Improved quality of life
Types of Targeted Molecular Therapy
Some types of targeted molecular therapy include:
- Selective BRAF inhibitor vemurafenib for BRAF mutant melanoma targets the protein (BRAF) involved in normal cell signaling. Mutations in the gene for BRAF are found in about half of melanomas as well as some other adult cancers. In melanoma the cancers uses the mutated BRAF protein to grow and spread. By interfering with the functions of the mutated BRAF protein with drugs such as vemurafenib, the melanoma tumors often stop growing and spreading, and in some cases even shrink.
- Imatinib and nilotinib target a protein (BCR-ABL) that is critical to the growth of chronic myelogenous leukemia cells
- Erlotinib targets a protein called the epidermal growth factor receptor or EGFR. This protein is involved in cell signaling and is mutated in up to 25 percent of lung cancers, especially in cancers developing in never or light smokers.
- Trastuzumab targets a cell signaling protein called HER2 that is overactive in about 25 percent of breast cancers.
- Other examples of targeted therapies include lapatinib for breast cancer; crizotinib for lung cancer; bevacizumab for lung and colon cancer; and sorafenib for liver and kidney cancer.
Diseases Treated with Targeted Molecular Therapy
Targeted molecular therapy is not indicated for all patients and all types of cancer. Currently, targeted molecular therapy is used to treat: