Nilotinib for the treatment of Philadelphia-chromosome-positive chronic myeloid leukemia

Analogs, formulations and derivatives of imatinib: a patent review

INTRODUCTION

The Bcr-Abl inhibitor imatinib was approved in 2001 for chronic myeloid leukemia therapy, and dramatically changed the lives of patients affected by this disease. Since it also inhibits platelet derived growth factor receptor (PDGFR) and c-Kit, imatinib is used for various other tumors caused by abnormalities of one or both these two enzymes.

AREAS COVERED

This review presents an overview on imatinib formulations and derivatives, synthetic methodologies and therapeutic uses that have appeared in the patent literature since 2008.

EXPERT OPINION

Innovative imatinib formulations, such as nanoparticles containing the drug, will improve its bioavailability. Moreover, oral solutions or high imatinib content tablets or capsules will improve patient compliance. Some solid formulations and innovative syntheses that have appeared in the last few years will reduce the cost of the drug, offering big advantages for poor countries. Some recently patented efficacious imatinib derivatives are in preclinical studies and could enter clinical trials in the next few years. Overall, Bcr-Abl inhibitors constitute a very appealing research field that can be expected to expand further.

Tyrosine kinase inhibition: a therapeutic target for the management of chronic-phase chronic myeloid leukemia

Chronic myeloid leukemia (CML) is a hematologic neoplasm with a progressive, ultimately terminal, disease course. In most cases, CML arises owing to the aberrant formation of a chimeric gene for a constitutively active tyrosine kinase. Inhibition of the signaling activity of this kinase has proved to be a highly successful treatment target, transforming the prognosis of patients with CML. New tyrosine kinase inhibitors continue to improve the management of CML, offering alternative options for those resistant to or intolerant of standard tyrosine kinase inhibitors. Here we review the pathobiology of CML and explore emerging strategies to optimize the management of chronic-phase CML, particularly first-line treatment.

Nilotinib population pharmacokinetics and exposure-response analysis in patients with imatinib-resistant or -intolerant chronic myeloid leukemia

PURPOSE

We evaluated the population pharmacokinetics (PK) and exposure-response relationship of nilotinib in patients with imatinib-resistant or -intolerant chronic myeloid leukemia (CML).

METHODS

Concentration data from 493 patients with CML in chronic phase (CML-CP), accelerated phase, or blast crisis were used to perform a population pharmacokinetic analysis using nonlinear mixed-effect modeling. Steady-state nilotinib trough concentrations (Cmin) in individual patients were estimated from the population PK model for correlation with the efficacy and safety variables. Exposure-efficacy analysis was performed in patients with CML-CP, whereas exposure-safety analysis was performed in all patients who had both nilotinib PK data and efficacy/safety measures available.

RESULTS

Baseline demographics and CML disease phase did not significantly affect nilotinib PK. Patients with a lower Cmin had significantly longer time to complete cytogenetic response (P = 0.010), longer time to major molecular response (P = 0.012), shorter time to progression (TTP; P = 0.009), and a trend toward lower response rates vs. patients with higher Cmin. A joint effect of prognostic risk score and Cmin on TTP was significant (P < 0.001). Nilotinib Cmin was also associated with the occurrence of all-grade elevations in total bilirubin (P < 0.001) and lipase (P = 0.002) levels.

CONCLUSIONS

When tolerability allows, adherence to the nilotinib dose (400 mg twice daily) in order to maintain sufficient Cmin is important in maximizing the efficacy of nilotinib in patients with imatinib-resistant or -intolerant CML.

BCR-ABL1 kinase domain mutations: methodology and clinical evaluation

The introduction of tyrosine kinase inhibitors (TKIs), starting with imatinib and followed by second and third generation TKIs, has significantly changed the clinical management of patients with chronic myeloid leukemia (CML). Despite their unprecedented clinical success, a proportion of patients fail to achieve complete cytogenetic remission by 12 months of treatment (primary resistance) while others experience progressive resistance after an initial response (secondary resistance). BCR-ABL1 kinase domain (KD) mutations have been detected in a proportion of patients at the time of treatment failure, and therefore their identification and monitoring plays an important role in therapeutic decisions particularly when switching TKIs. When monitoring KD mutations in a clinical laboratory, the choice of method should take into account turnaround time, cost, sensitivity, specificity, and ability to accurately quantify the size of the mutant clone. In this article, we describe in a "manual" style the methods most widely used in our laboratory to monitor KD mutations in patients with CML including direct sequencing, D-HPLC, and pyrosequencing. Advantages, disadvantages, interpretation of results, and their clinical applications are reviewed for each method.