Now more than ever, oncology has more targeted therapy available and this continues to evolve and will be the ongoing future for cancer care and treatment.
One of the mavericks of TKIs is Gleevec (imatinib mesylate), which was discovered by an evolution of progress by various chemists who worked on the emerging molecular genetics for chronic myeloid leukemia (CML). It was a pharmaceutical company in Basel, Switzerland that was researching drugs that would inhibit kinases (one of the identified molecules found in CML patients' bone marrow). After much trial and error, this early work was shared with a young faculty member from Dana-Farber Cancer Institute (Brian Druker) in Boston. This eventually led to discovery that, within a petri dish, leukemic cells from CML bone marrow died immediately when the formula for Gleevec was added to the dish.
Gleevec is classified as a signal transduction inhibitor: a protein-tyrosine kinase inhibitor. It uses small molecules that are able to enter the malignant cell and disrupt the cell function and apoptosis in a unique way: targeting the Bcr-abl (a kinase) gene. The single translocation of this gene was a unique factor to leukemia.
Today, Gleevec is an oral medication usually taken one or twice per day (with a meal and water to lessen GI side effects) for CML or gastrointestinal stromal tumors that are C-kit (a kinase) positive.
Some of the side effects are the same as other chemotherapy regimens: myelosuppression, nausea and vomiting, edema (swelling of the face, feet, hands), skin rash, muscle cramps and bone pain, diarrhea, fever and cardiac toxicity. Liver toxicity is a possibility, too.
The side effect I have seen with this treatment is a skin rash. Usually harmless, but very uncomfortable for the patient. It can develop on any part of the body, usually several weeks after being on this medication. It is characterized as small bumps with red skin covering large areas, scaly at times, itchy and irritating.
Some over the counter products can help, such as oatmeal baths and hydrocortisone cream, but if is persists, the patient needs to inform their physician as soon as the rash develops and may be referred to a dermatologist. Usually, an oral antihistamine or systemic corticosteroid is prescribed initially. This rash is seen with other TKIs too and that is due to the fact that TKIs are part of the ErbB family, a cousin that includes epidermal growth factors. Therefore affecting skin in an indirect way.
Educating patients to the common side effects of TKIs and encouraging them to call is the best way to quickly and proactively address side effects, providing relief and assurance to the patients undergoing treatment.
- Novartis Pharmaceuticals Corporation. Serious adverse reactions to GLEEVEC (imatinib mesylate). Available at http://www.gleevec.com/health-care-professional/index.jsp?site=PC008403&irmasrc=NA&source=01030.
- Gobel, B.H., Triest-Robertson, S., & Vogel, W.H. (2009). Advanced Oncology Nursing Certification Review and Resource Manual. Oncology Nursing Society. Pittsburgh, Pennsylvania.
- Mukherjee, S. (2010). The Emperor of All Maladies: A Biography of Cancer. Simon and Schuster.
New York, NY.
- Newton, S., Hickey, M. & Marrs, J. (2009) Mosby’s Oncology Nursing Advisor: A Comprehensive Guide to Clinical Practice. Mosby Elsevier. St. Louis, Missouri.