In the initial treatment of chronic myeloid leukemia (CML), Tasigna® (nilotinib) appears to produce higher response rates than Gleevec® (imatinib) 400 mg/day. These results were presented at the 2009 meeting of the American Society of Hematology (ASH).
CML is a cancer that originates in the immune cells. It affects approximately 5,000 people annually in the United States. In the case of CML, large numbers of young immune cells do not mature, resulting in an excess accumulation of these cells. These leukemia cells then crowd the bone marrow and blood, suppressing formation and function of other blood cells normally present in these areas. In addition, the leukemia cells cannot perform their function properly, leaving patients susceptible to infection.
Gleevec 400 mg/day is a standard initial treatment for newly diagnosed patients with CML. Gleevec produces a high rate of cytogenetic remissions and major molecular responses, but most patients have residual disease.
Tasigna is an oral agent that has produced cytogenetic remissions in patients intolerant to or resistant to Gleevec. Tasigna also has modest activity in patients who had failed both Gleevec and Sprycel® (dasatinib).
To compare Tasigna with Gleevec in the initial treatment of CML, researchers conducted a study among 846 patients with newly diagnosed, Philadelphia chromosome-positive, chronic-phase CML. Patients were assigned to one of three treatment groups:
- Gleevec 400 mg per day
- Tasigna 300 mg twice per day
- Tasigna 400 mg twice per day
Rates of major molecular response were 44% among patients treated with Tasigna 300 mg twice per day, 43% for Tasigna 400 mg twice per day, and 22% for Gleevec 400 mg per day.
Rates of complete cytogenetic response were 80% among patients treated with Tasigna 300 mg twice per day, 78% for Tasigna 400 mg twice per day, and 65% for Gleevec 400 mg per day.
All treatments were well tolerated.
These results suggest that Tasigna may be more effective than Gleevec 400 mg/day for the initial treatment of CML.
Saglio G, Kim D-W, Issaragrisil S, et al. Nilotinib Demonstrates Superior Efficacy Compared with Imatinib in Patients with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase: Results From the International Randomized Phase III ENESTnd Trial. Blood. 2009;114: Abstract LBA-1.