American Board of Internal Medicine (ABIM) Certification Practice Exam

Which among the following therapies is indicated for chronic myeloid leukemia?

1. Chemotherapy using doxorubicin

2. Imatinib or second-generation TKIs

3. Bone marrow transplant only

4. Only supportive care

The correct answer is: Imatinib or second-generation TKIs

The indicated therapy for chronic myeloid leukemia (CML) is imatinib or second-generation tyrosine kinase inhibitors (TKIs). This specificity arises from the unique pathophysiology of CML, which is characterized by the presence of the Philadelphia chromosome, resulting from the fusion of the BCR and ABL genes. This fusion encodes a constitutively active tyrosine kinase that drives the proliferation of myeloid cells. Imatinib, as a first-generation TKI, specifically inhibits this BCR-ABL protein, leading to a significant reduction in the number of leukemic cells and improving survival rates. The introduction of second-generation TKIs, such as dasatinib and nilotinib, has further enhanced treatment options for patients, especially those who are intolerant to or have disease that is resistant to imatinib. These TKIs have been shown to offer faster and deeper hematologic and cytogenetic responses. While chemotherapy with drugs like doxorubicin is a common treatment for various malignancies, it is not typically effective for CML due to the disease's unique biology and the availability of targeted therapies. Bone marrow transplant can be curative, but it is not the first-line therapy and is usually reserved