Molecular Pathology Laboratory Network

The US Food and Drug Administration (FDA) has approved nilotinib (Tasigna, Novartis) as a first-line treatment of chronic-phase Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML).

Approval was based on clinical trials results that found nilotinib to be superior to imatinib (Gleevec®, Novartis) in achieving major molecular and complete cytogenetic responses. The data showed patients who received nilotinib, either 300 mg or 400 mg twice daily, had a significant improvement in time to progression to the accelerate phase (P = .01) or blast crisis (P = .004), compared with imatinib.

Results of the study were presented at the recent American Society of Clinical Oncology (ASCO) 2010 Annual Meeting, simultaneously published in the New England Journal of Medicine, and reported by Medscape Oncology.

Nilotinib is a second-generation tyrosine kinase inhibitor and is a more potent and selective inhibitor of the BCR-ABL protein than imatinib, according to the study. It is also active against a broad spectrum of BCR-ABL mutations associated with resistance to imatinib, and received regulatory approval in 2007 as a second-line treatment for CML.

To assist physicians with treatment decisions for CML patients failing molecular response, MPLN performs ABL Kinase gene mutation analysis to determine resistance to BCR-ABL tyrosine kinase inhibitor (TKI) therapy.

The degree of resistance depends on specific ABL mutations a patient carries, and thus whether they can be successfully treated with one of the second generation drugs such as nilotinib.

For more information about miminal residual disease testing and ABL Kinase gene mutation analysis performed by MPLN, contact a client service specialist at 800-932-2943.