Tyrosine kinase inhibitors for the treatment of Chronic Myeloid Leukaemia, February 2014
Page last updated: 6 March 2015
Drug utilisation sub-committee (DUSC)
February 2014
Abstract
Purpose
The DUSC requested an analysis of the utilisation of PBS-listed tyrosine kinase inhibitors (TKIs), imatinib, dasatinib and nilotinib, for the treatment of CML. This analysis is a part of the routine analyses conducted by the DUSC investigating how the current utilisation of PBS medicines compares with the use as recommended by the PBAC.
Background
Imatinib, dasatinib and nilotinib inhibit the activity of the abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in patients with chronic myeloid leukaemia.
The PBS restrictions for the TKIs for CML have evolved over time. The current PBS restrictions, when used in accordance with certain criteria, include:
- imatinib, dasatinib and nilotinib as first line therapy in the treatment of the chronic phase of CML. Patients can switch between the three drugs within first line if intolerant, but not if they have failed;
- imatinib in accelerated or blast phase;
- dasatinib, after failure of first line imatinib or nilotinib, in any phase; and
- nilotinib, after failure of first line imatinib or dasatinib, in the chronic or accelerated phase.
Authority applications are managed by the Department of Human Services (DHS) Medicare Specialised Drugs area. Initial applications require prior written approval. Subsequent applications for imatinib can be made by telephone.
Date of listing on PBS
For CML:
- Imatinib: December 2001;
- dasatinib: August 2007;
- nilotinib: August 2008.
Data Source
The DHS Medicare prescription database provided supplied R/PBS prescription data and associated expenditure. The DHS Medicare Authority Approval database provided supplementary data on the phase of the disease and whether use was initial or continuing treatment.
Key Findings
- The number of patients on treatment, number of prescriptions and expenditure of TKIs for CML has increased steadily (i.e. linear tread) over a 12 year period from 2001 to 2013. This reflects the increasing prevalence of CML as mortality from CML declines and patients continue on treatment. Utilisation is expected to continue to increase in the future.
- The DUSC considered that the steadily increasing expenditure for TKIs in CML is explicable entirely on the basis of increased survival.
- The number of new patients commencing treatment has remained stable. This trend is consistent with incidence of CML reported by the AIHW.
- Listing of dasatinib and nilotinib for chronic phase CML after failure of imatinib, and subsequently as first line therapy, has not had a noticeable impact on the steady upward trend in prevalent patients, prescription utilisation and expenditure for CML drugs.
