This year’s AML (acute myeloid leukemia) World Awareness Day on April 21, 2019, marks the continued evolution of promising treatment possibilities for patients with AML. Recent biomarker identification and targeted therapy approvals have inaugurated a new outlook for patients with AML under the auspices of precision medicine. Previously beset with poor overall survival rates, AML is now treated with targeted therapies that are extending lives. But the success of these treatments depends entirely on vigilant and timely testing with the right test at the right time. It also means testing again if relapse occurs.
AML, which affects approximately 30% of patients with leukemia,1 is a rapidly developing cancer that requires immediate and appropriate treatment. Misdiagnoses and delayed treatment can mean the difference between life and death for patients, for whom the 5-year overall survival rate is only 25%.1 This is why getting the right test at the outset, and again if relapse occurs, is so critical.
New treatments for AML target genetic abnormalities in blood cells that characterize AML. Some of the genes that are commonly identified as abnormal in AML include FLT3, IDH1, and IDH2.2-4 For example, approximately one-third of patients with AML have FLT3-internal tandem duplication (ITD) mutations, which indicate a particularly poor prognosis for patients.5-9 By identifying biomarkers and genetic mutations such as FLT3 through genetic* testing, physicians are now able to tailor treatment plans to patients with AML with targeted therapies that target these individual genetic abnormalities on a patient-by-patient basis. For example, targeted therapy for patients with FLT3 mutations is initiated with chemotherapy. Similarly, separate targeted therapies are indicated for patients with the IDH1 or IDH2 gene mutations who did not respond to initial therapy (refractory) or who relapsed after initial therapy.
Since targeted therapy is effective only when given to patients identified as having the certain biomarker the treatment targets, it is imperative that genetic testing occur at diagnosis. But testing only at diagnosis is not enough. Mutational status can change within individual patients. Specifically, because of clonal evolution in AML, mutational status may change in patients after relapse.10-13 For example, FLT3 is not a stable biomarker and may not show up at diagnosis.14 However, it can emerge after relapse, making it imperative that patients be tested for the presence of FLT3 mutations not just at diagnosis but also at relapse.14 This means new treatment options may be considered after diagnosis if patients relapse, which is a crucial development as many patients with AML die from progressive disease following relapse.15 If new mutations are identified after relapse, new targeted treatments can be applied to improve health outcomes. But those mutations won’t be identified without vigilant testing.
*Also referred to as molecular testing.