This case involves a 33-year-old obese woman with leukemia who developed a fatal plaque buildup in her arteries after receiving chemotherapy treatment. Upon discovery of her leukemia, the patient was treated with imatinib mesylate. Within 3 months of her initial treatment, the patient developed occlusion of her femoral artery and severely high cholesterol. The patient was admitted for an angioplasty procedure, during which she suffered a fatal stroke. The autopsy revealed 85% occlusion throughout her body. It was alleged that the pharmaceutical manufacturer did not put proper warning labels to inform physicians of the drug’s dangers. An expert in oncology was sought to opine on whether there is a link between imatinib mesylate and high cholesterol.
Question(s) For Expert Witness
- 1. Please describe your background in treating leukemia?
- 2. What are the risks involved in using imatinib mesylate to treat leukemia?
Expert Witness Response E-034164
I have had a long, 25+ year-long academic career as a leukemia doctor and clinical leukemia researcher. I spent the first 19 years of my career on the Leukemia Service at a prestigious cancer treatment center where I saw patients and participated in clinical research on adult leukemias. I participated in the care of thousands of patients with leukemia and hundreds with bone marrow cancer. At my most recent appointment, I oversaw all aspects of clinical care and research for patients with bone marrow based diseases including bone marrow cancer. It is now very clear that the targeted agents used to treat bone marrow cancer can have toxic effects. Imatinib mesylate appears to be the worst choice in terms of cardiovascular disease. This risk was not appreciated at the time imatinib mesylate was FDA approved, but subsequent data is very convincing. The most important point in my mind is the timeline in terms of what was known at the time this patient was on imatinib mesylate and what the pharmaceutical company did to inform patients and doctors about changes to informed consent and monitoring for atherosclerotic disease. I understand the proposed mechanism of action of imatinib mesylate on the vascular endothelium quite well — though, while we know it can cause accelerated atherosclerosis, the precise mechanism of action is not known with absolute certainty. I also understand the risks and balances for using the various approved TKIs for treating bone marrow cancer and I believe that knowledge is critical in assessing the risks and/or rewards involved when using imatinib mesylate.