Targeted therapy is a type of cancer treatment that uses drugs to specifically target cancer cells or the processes that enable their growth and spread, while minimizing damage to healthy cells. Unlike chemotherapy, which kills both cancerous and healthy cells, targeted therapy drugs are designed to attack specific molecules or pathways that are essential for cancer cell survival and proliferation. This approach can lead to fewer side effects and better treatment outcomes in some cases. There are several types of targeted therapy drugs that are used to treat different types of cancer. In this answer, we will discuss the most common types of targeted therapy drugs and their mechanisms of action.
Tyrosine kinase inhibitors (TKIs)
Tyrosine kinase inhibitors are a type of targeted therapy drug that interfere with the signaling pathways that are activated by certain proteins called tyrosine kinases. These proteins are often overactive in cancer cells and promote tumor growth and spread. TKIs work by binding to the tyrosine kinase proteins and blocking their activity, which can slow down or stop cancer cell growth. Some examples of TKIs include imatinib (Gleevec), dasatinib (Sprycel), and erlotinib (Tarceva). These drugs are used to treat a variety of cancers, including chronic myeloid leukemia, gastrointestinal stromal tumors, and non-small cell lung cancer.
Monoclonal antibodies
Monoclonal antibodies are a type of targeted therapy drug that are designed to recognize and bind to specific proteins on the surface of cancer cells. Once bound, the antibodies can trigger an immune response that destroys the cancer cells or blocks their growth and spread. Some monoclonal antibodies, such as rituximab (Rituxan), target proteins that are specific to certain types of cancer cells, such as lymphoma. Other monoclonal antibodies, such as trastuzumab (Herceptin), target proteins that are overexpressed in some breast cancers. Monoclonal antibodies can also be used in combination with chemotherapy or other targeted therapy drugs to enhance their effectiveness.
Proteasome inhibitors
Proteasome inhibitors are a type of targeted therapy drug that block the activity of proteasomes, which are cellular complexes that break down and recycle proteins. Cancer cells rely on proteasomes to dispose of proteins that are no longer needed or that are damaged, as part of their normal metabolic processes. By inhibiting proteasome activity, these drugs can cause a buildup of proteins in cancer cells, leading to cell death. Bortezomib (Velcade) is a proteasome inhibitor that is used to treat multiple myeloma and some types of lymphoma.
PARP inhibitors
PARP inhibitors are a type of targeted therapy drug that interfere with the activity of an enzyme called poly (ADP-ribose) polymerase (PARP). PARP is involved in repairing damaged DNA in cells, including cancer cells. By inhibiting PARP activity, these drugs can prevent cancer cells from repairing DNA damage, leading to their death. PARP inhibitors are particularly effective in cancers that have defects in the genes that control DNA repair, such as BRCA1 and BRCA2 mutations. Some examples of PARP inhibitors include olaparib (Lynparza) and rucaparib (Rubraca).
Angiogenesis inhibitors
Angiogenesis inhibitors are a type of targeted therapy drug that interfere with the formation of new blood vessels that tumors need to grow and spread. These drugs work by targeting proteins that stimulate the growth of blood vessels, such as vascular endothelial growth factor (VEGF). By blocking VEGF or other angiogenic proteins, angiogenesis inhibitors can starve cancer cells of the nutrients and oxygen they need to survive. Some examples of angiogenesis inhibitors include bevacizumab (Avastin) and ramucirumab (Cyramza).
Hormone therapies
Hormone therapies are a type of targeted therapy drug that interfere with the activity of hormones that promote the growth of certain types of cancer cells, such as breast and prostate cancers. These drugs work by blocking the production or activity of hormones such as estrogen or testosterone, which can slow down or stop cancer cell growth. Examples of hormone therapies include tamoxifen (Nolvadex) and aromatase inhibitors, which are used to treat breast cancer, and androgen receptor inhibitors, which are used to treat prostate cancer.
In conclusion, targeted therapy drugs are an important class of cancer treatments that are designed to specifically target cancer cells or the processes that enable their growth and spread, while minimizing damage to healthy cells. There are several types of targeted therapy drugs that are used to treat different types of cancer, including tyrosine kinase inhibitors, monoclonal antibodies, proteasome inhibitors, PARP inhibitors, angiogenesis inhibitors, and hormone therapies. These drugs can be used alone or in combination with other cancer treatments, such as chemotherapy or radiation therapy, to improve treatment outcomes and quality of life for cancer patients.
