In a nutshell
This study examined whether the newly developed ‘EUTOS’ score can predict treatment outcomes of imatinib (Gleevac) for chronic myeloid leukemia (CML). Researchers reported that the new ‘EUTOS’ score was associated with high predictive accuracy of treatment outcomes of imatinib.
Some background
In recent years, targeted therapy has become the standard first-line treatment for CML. Targeted therapy is a type of treatment that uses drugs or small molecules that block the growth and spread of cancer. Tyrosine kinase inhibitors (TKIs), such as imatinib, are a type of targeted therapy that block enzymes called tyrosine kinases involved in cancer growth. TKIs are the treatment of choice for CML.
Finding markers that can predict clinical outcomes is important for appropriate treatment selection. Models used to allocate patients into risk groups include the ‘EURO’ and the ‘Sokal’ systems. These use factors such as age, spleen size, and the immature cell, platelet and white blood cell counts in the blood. These models were developed before the use of TKIs. A newer model called ‘EUTOS’ calculates a risk score based only on spleen size and basophils in the blood (a type of white blood cell). The accuracy of the ‘EUTOS’ score in predicting treatment outcomes with TKIs is still being investigated.
Methods & findings
The aim of this study was to examine whether the new ‘EUTOS’ score can predict treatment response to imatinib.
2,060 CML patients treated with imatinib were included in this study. The accuracy of the different models in predicting treatment outcomes was compared. Patients were followed for an average of 42 months.
According to the ‘EURO’ score, 38% of the patients were considered low-risk. 51% of patients were classified as intermediate-risk. 11% of patients had high-risk disease. According to the ‘Sokal’ score, 39% were low-risk, 37% were intermediate-risk, and 24% were high-risk.
Overall survival (proportion who have not died from any cause since treatment) at 60 months was 91%. At 36 months, 92% of patients were showing treatment response to imatinib. Patients who had not achieved treatment response after 6 months had an 8% risk of disease progression. This increased to 14% after 12 months and 23% after 18 months.
The accuracy of the ‘EURO’ score in predicting treatment response at 18 months was 26%. This was 25% for the ‘Sokal’ score. Predictive accuracy was highest for the new ‘EUTOS’ score. It was able to predict treatment response in 34% of patients at 18 months. 90% of patients in the low-risk ‘EUTOS’ group were progression-free at 5 years. This was significantly higher compared to patients in the high-risk ‘EUTOS’ group (82%).
The bottom line
Researchers concluded that the new ‘EUTOS’ score can accurately predict treatment outcomes in CML patients treated with imatinib.
Published By :
Blood
Date :
Jul 21, 2011
