First-Line Therapy for Chronic Myeloid Leukemia

The standard first-line drug therapy for chronic myeloid leukemia (CML) is Imatinib. It is a targeted therapy known as a tyrosine kinase inhibitor (TKI).

Rationale for Imatinib

• Mechanism: Imatinib specifically inhibits the BCR-ABL tyrosine kinase, the abnormal protein driving CML proliferation.
• Efficacy: It has shown high rates of cytogenetic and molecular response, significantly improving patient outcomes compared to older treatments.
• Standard of Care: Imatinib is widely recognized and recommended as the initial treatment choice for patients diagnosed with Philadelphia chromosome-positive (Ph+) CML in the chronic phase.

Other Options

• Hydroxycarbamide: Can be used for cytoreduction but is not a targeted therapy and less effective long-term for CML.
• Alpha interferon: An older immunotherapy; largely replaced by TKIs due to lower efficacy and poorer tolerability.
• Busulphan: A chemotherapy alkylating agent, historically used but generally reserved for specific situations or later lines of therapy due to toxicity and lack of specificity compared to TKIs.

Therefore, Imatinib is the correct first-line therapy.