Targeted cancer therapies are a class of drugs that inhibit cancer growth and spread by interfering with specific cellular molecules involved in driving the carcinogenic process. Therapeutically relevant targets include signal pathway initiators, mediators, and checkpoints that control cell growth, proliferation, differentiation, and survival. Other targets play important roles in modulating angiogenesis, metastasis, and immune escape. Targeted therapy is generally better tolerated by the patient over traditional chemotherapy since it offers more precision in targeting abnormal cancer pathways, thus minimizing drug effects on normal tissues. However, targeted agents are not without potentially significant side effects (i.e., rash, diarrhea, vomiting, bleeding, gastrointestinal perforation, myelosuppression, mucositis, acral erythema, neutropenia, dyspnea, cardiac dysfunction, thrombosis, hypertension, proteinuria, fatigue). Nevertheless, targeted cancer therapies provide clinicians a way to tailor cancer treatment to a unique set of molecular targets within the patient’s tumor.
Most targeted therapies can be classified as either a small-molecule drug or a monoclonal antibody:
Small molecule inhibitors enter the cell and generally function by inhibiting activity of a specific protein or group of proteins, usually kinases. Small molecule inhibitors have been particularly successful in the treatment of patients with certain types of lung cancer (EGFR inhibitors such as erlotinib and gefintib, ALK inhibitors such as crizotinib), melanoma (BRAF inhibitors such as vemurafenib and dabrafenib, MEK inhibitors such as trametinib), breast cancer (HER2/ERBB2 inhibitors such as lapatinib), chronic myelogenous leukemia (BCR-ABL inhibitors such as imatinib mesylate and dasatinib), and gastrointestinal stromal tumor (KIT inhibitors such as imatinib mesylate).
Therapeutic monoclonal antibodies cannot enter the cell and usually bind to cell-surface receptors. Drug effects may include blocking target protein function, locating a toxin to the tumor cells or promoting immune targeting of the cancer cell. Therapeutic monoclonal antibodies have been particularly successful in the treatment of a subset of patients with breast cancer (HER2/ERBB2 antibodies such as trastuzumab), colon cancer (EGFR antibodies such as cetuximab and panitumumab) and squamous cell carcinoma of the head and neck (EGFR antibodies such as cetuximab).
The number of targeted cancer therapies undergoing clinical trial evaluation and receiving approval by the U.S. Food and Drug Administration (FDA) are rapidly expanding. Furthermore, results from ongoing clinical trials that are evaluating targeted therapy combinations are widely anticipated for determining the most appropriate route for overcoming drug resistance in advanced cancer patients. Therefore, staying informed of the recent advances in targeted therapy consensus use and emerging evidence is a significant challenge for any oncologist. This website was thus developed by clinicians and translational scientists as a resource which contains the most up-to-date content on genotype-directed use of targeted cancer therapy and clinical trial opportunities.