Nilotinib is effective in patients with chronic myeloid leukemia in chronic phase after imatinib resistance or intolerance: 24-month follow-up results.

Nilotinib is a potent selective inhibitor of the BCR-ABL tyrosine kinase approved for use in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP), and in CML-CP and CML-accelerated phase after imatinib failure. Nilotinib (400 mg twice daily) was approved on the basis of the initial results of this phase 2 open-label study. The primary study endpoint was the proportion of patients achieving major cytogenetic response (CyR). All patients were followed for ≥ 24 months or discontinued early. Of 321 patients, 124 (39%) continue on nilotinib treatment. Overall, 59% of patients achieved major CyR; this was complete CyR (CCyR) in 44%. Of patients achieving CCyR, 56% achieved major molecular response. CyRs were durable, with 84% of patients who achieved CCyR maintaining response at 24 months. The overall survival at 24 months was 87%. Adverse events were mostly mild to moderate, generally transient, and easily managed. This study indicates that nilotinib is effective, with a manageable safety profile, and can provide favorable long-term benefits for patients with CML-CP after imatinib failure.

Population pharmacokinetic and exposure-response analysis of nilotinib in patients with newly diagnosed Ph+ chronic myeloid leukemia in chronic phase.

PURPOSE: We investigated the population pharmacokinetics and exposure-response relationship of nilotinib in patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase. METHODS: Nilotinib was given at 300 mg or 400 mg twice daily. Serum concentration data (sparse and full pharmacokinetic profiles) were obtained from 542 patients over 12 months. A population pharmacokinetic analysis was performed using nonlinear mixed-effect modeling. Exposure-response relationships were explored graphically or using logistic regression models. RESULTS: Nilotinib concentrations were stable over 12 months. Patients in the 400 mg twice-daily arm had an 11.5% higher exposure than did those in the 300 mg twice-daily arm, and the relative bioavailability of nilotinib 400 mg twice daily was 0.84 times that of 300 mg twice daily. Patient demographics did not significantly affect nilotinib pharmacokinetics. The occurrence of all-grade total bilirubin elevation was significantly higher in patients with higher nilotinib exposure, and a positive correlation was also observed between nilotinib exposure and QTcF change on electrocardiograms from baseline. There was no significant relationship between nilotinib exposure and major molecular response at 12 months. CONCLUSIONS: There is a less than proportional dose-exposure relationship between nilotinib 300 mg and 400 mg twice-daily doses. Blood level testing is unlikely to play an important role in the general management of patients with newly diagnosed CML treated with nilotinib.

Nilotinib versus imatinib for the treatment of patients with newly diagnosed chronic phase, Philadelphia chromosome-positive, chronic myeloid leukaemia: 24-month minimum follow-up of the phase 3 randomised ENESTnd trial.

BACKGROUND: Nilotinib has shown greater efficacy than imatinib in patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukaemia (CML) in chronic phase after a minimum follow-up of 12 months. We present data from the Evaluating Nilotinib Efficacy and Safety in clinical Trials-newly diagnosed patients (ENESTnd) study after a minimum follow-up of 24 months. METHODS: ENESTnd was a phase 3, multicentre, open-label, randomised study. Adult patients were eligible if they had been diagnosed with chronic phase, Philadelphia chromosome-positive CML within the previous 6 months. Patients were randomly assigned (1:1:1) to receive nilotinib 300 mg twice a day, nilotinib 400 mg twice a day, or imatinib 400 mg once a day, all administered orally, by use of a computer-generated randomisation schedule, using permuted blocks, and stratified according to Sokal score. Efficacy results are reported for the intention-to-treat population. The primary endpoint was major molecular response at 12 months, defined as BCR-ABL transcript levels on the International Scale (BCR-ABL(IS)) of 0·1% or less by real-time quantitative PCR in peripheral blood. This study is registered with ClinicalTrials.gov, number NCT00471497. FINDINGS: 282 patients were randomly assigned to receive nilotinib 300 mg twice daily, 281 to receive nilotinib 400 mg twice daily, and 283 to receive imatinib. By 24 months, significantly more patients had a major molecular response with nilotinib than with imatinib (201 [71%] with nilotinib 300 mg twice daily, 187 [67%] with nilotinib 400 mg twice daily, and 124 [44%] with imatinib; p<0·0001 for both comparisons). Significantly more patients in the nilotinib groups achieved a complete molecular response (defined as a reduction of BCR-ABL(IS) levels to ≤0·0032%) at any time than did those in the imatinib group (74 [26%] with nilotinib 300 mg twice daily, 59 [21%] with nilotinib 400 mg twice daily, and 29 [10%] with imatinib; p<0·0001 for nilotinib 300 mg twice daily vs imatinib, p=0·0004 for nilotinib 400 mg twice daily vs imatinib). There were fewer progressions to accelerated or blast phase on treatment, including clonal evolution, in the nilotinib groups than in the imatinib group (two with nilotinib 300 mg twice daily, five with nilotinib 400 mg twice daily, and 17 with imatinib; p=0·0003 for nilotinib 300 mg twice daily vs imatinib, p=0·0089 for nilotinib 400 mg twice daily vs imatinib). At 24 months, survival was comparable in all treatment groups, but fewer CML-related deaths had occurred in both the nilotinib groups than in the imatinib group (five with nilotinib 300 mg twice daily, three with nilotinib 400 mg twice daily, and ten with imatinib). Overall, the only grade 3 or 4 non-haematological adverse events that occurred in at least 2·5% of patients were headache (eight [3%] with nilotinib 300 mg twice daily, four [1%] with nilotinib 400 mg twice daily, and two [<1%] with imatinib) and rash (two [<1%], seven [3%], and five [2%], respectively). Grade 3 or 4 neutropenia was more common with imatinib than with either dose of nilotinib (33 [12%] with nilotinib 300 mg twice daily, 30 [11%] with nilotinib 400 mg twice daily, and 59 [21%] with imatinib). Serious adverse events were reported in eight additional patients in the second year of the study (four with nilotinib 300 mg twice daily, three with nilotinib 400 mg twice daily, and one with imatinib). INTERPRETATION: Nilotinib continues to show better efficacy than imatinib for the treatment of patients with newly diagnosed CML in chronic phase. These results support nilotinib as a first-line treatment option for patients with newly diagnosed disease. FUNDING: Novartis.

Expanding Nilotinib Access in Clinical Trials (ENACT), an open-label multicenter study of oral nilotinib in adult patients with imatinib-resistant or -intolerant chronic myeloid leukemia in accelerated phase or blast crisis.

Nilotinib has shown favorable safety in patients with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic (CML-CP) or accelerated phase (CML-AP) who failed prior imatinib, and superior efficacy over imatinib in newly diagnosed Ph+ patients with CML-CP. Reported here are the efficacy and safety data for patients in CML-AP (n = 181) or blast crisis (CML-BC) (n = 190; myeloid BC, 133; lymphoid BC, 50; unknown, seven) enrolled in an expanded access phase IIIb study. Non-hematologic adverse events were mostly mild to moderate. Drug-related myelosuppression was generally manageable with dose reductions or interruptions and infrequently led to discontinuation of nilotinib. Drug-related grade 3/4 elevations in serum bilirubin and lipase were infrequent. While an analysis of efficacy was not the primary objective of this study, significant hematologic and cytogenetic responses were observed. These results support the safety and efficacy of nilotinib in patients with advanced CML in AP and BC.