Middle-aged patients respond better to first-line treatment with imatinib than young and elderly patients

This study examined the effect of age on treatment response to imatinib (Gleevac) for chronic myeloid leukemia (CML). Researchers reported the best clinical outcomes in patients aged between 45 and 65 years.

Treatment response for CML is often measured based on patients showing less abnormal chromosomes (cytogenetic response) or genetic abnormalities (molecular response) in the blood or bone marrow. Major molecular response is often considered the main goal of CML treatment.

Targeted therapy has become the standard first-line treatment for CML. This refers to a type of treatment that uses drugs or small molecules that block the growth and spread of cancer. Tyrosine kinase inhibitors, such as imatinib, are a type of targeted therapy that block enzymes called tyrosine kinases. Whether age affects treatment response to imatinib is still being investigated.

This study analyzed the records of 101 CML patients receiving first-line treatment with imatinib. 33 patients were aged between 18 and 44 years (young patients). 38 patients were aged between 45 and 65 years (middle-age). 30 patients were older than 65 years (elderly patients). Treatment outcomes were followed for an average of 54.2 months.

Complete cytogenetic response rates were similar across age groups. They were 81.8% for young patients, 86.8% for middle-aged patients, and 76.7% for elderly patients. 84.2% of middle-aged patients achieved major molecular response. This was significantly higher compared to younger patients (63.6%) and elderly patients (60%).

The number of deaths from CML and other causes was highest among elderly patients. The 6-year overall survival rate (proportion who have not died from any cause since treatment) was 73.5% in this group. Overall survival at 6 years was significantly higher in young patients (90.8%) and middle-aged patients (86.4%).

The risk of a treatment-related event such as disease progression or death was significantly lower in middle-aged patients. 75.5% of middle-aged patients were event-free at 6 years. In comparison, 58.6% of young patients and 43.4% of elderly patients were event-free at 6 years.

Side effects were more common in elderly patients. 26.7% of elderly patients showed blood-related side effects. 40% had side effects not related to blood results. These included fluid retention, nausea, muscle pain, skin reaction, and fatigue. 27.3% of young patients and 21.1% of middle-aged patients reported similar side effects.

Researchers concluded that middle-aged patients showed the best response to imatinib treatment with longer survival compared to young and elderly patients.