The results of a recent phase 3 randomized trial support the use of nilotinib as a first-line treatment option for persons with newly diagnosed chronic myeloid leukemia (CML), according to the study investigators. In the trial, nilotinib (Tasigna) proved to be more effective than imatinib (Gleevec). Both drugs are manufactured by Novartis, which funded the study.
In the multicenter Nilotinib Efficacy and Safety in Clinical Trials–newly diagnosed patients (ENESTnd) study, 282 persons were randomly assigned to receive nilotinib 300 mg twice daily, 281 to receive nilotinib 400 mg twice daily, and 283 to receive imatinib 400 mg once daily, all administered orally. All patients received diagnoses of chronic phase, Philadelphia chromosome-positive CML within the preceding 6 months.
By 24 months, significantly more patients had a major molecular response with nilotinib than with imatinib: 201 (71%) with nilotinib 300 mg, 187 (67%) with nilotinib 400 mg, and 124 (44%) with imatinib. In addition:
- Significantly more patients in the nilotinib groups achieved a complete molecular response at any time than did those in the imatinib group—74 (26%) with nilotinib 300 mg, 59 (21%) with nilotinib 400 mg, and 29 (10%) with imatinib.
- Fewer people on nilotinib than on imatinib progressed to accelerated or blast phase on treatment, including clonal evolution (two persons with nilotinib 300 mg, five with nilotinib 400 mg, and 17 with imatinib).
- Survival was comparable in all treatment groups at 24 months, but fewer CML-related deaths occurred in the nilotinib groups (five deaths with nilotinib 300 mg; three with nilotinib 400 mg) than in the imatinib group (10 deaths).
Grade 3 or 4 neutropenia was more common with imatinib use than with either dose of nilotinib. Overall, the only grade 3 or 4 nonhematological adverse events to occur in at least 2.5% of patients were headache (in 3% of the nilotinib 300 mg patients, 1% of the nilotinib 400 mg patients, and less than 1% of the imatinib patients), and rash (in less than 1% of the nilotinib 300 mg patients, 3% of the nilotinib 400 mg patients, and 2% of the imatinib patients).
“Nilotinib continues to show better efficacy than imatinib for the treatment of patients with newly diagnosed CML in chronic phase,” wrote the authors in The Lancet Oncology (2011;12:841-851). “These results support nilotinib as a first-line treatment option for patients with newly diagnosed disease.”