Note
TREATMENT OF PATIENTS WITH CHRONIC MYELOID LEUKAEMIA - SECOND-LINE THERAPY
The following information applies to the prescribing under the Pharmaceutical Benefits
Scheme (PBS) of tyrosine kinase inhibitors (TKI) agents for all phases of chronic
myeloid leukaemia (CML) in the second-line treatment setting.
Where the term TKI agent appears in the following notes and restrictions it refers
to dasatinib or nilotinib.
Patients are eligible for PBS-subsidised second-line treatment of CML if they have
experienced treatment failure in the first-line treatment setting.
Patients are eligible for PBS-subsidised treatment with either dasatinib or nilotinib
if they have not failed prior PBS-subsidised treatment with either dasatinib or nilotinib
in the first-line treatment setting. Patients are eligible for PBS-subsidised treatment
with either dasatinib or nilotinib at any one time and must not be receiving concomitant
interferon alfa therapy. Eligible patients may only swap between these agents if they
have not failed prior PBS-subsidised treatment with that agent and may only occur
for reasons of intolerance.
Dasatinib is PBS-subsidised for all phases of CML (chronic, accelerated and blast
phase) in the second-line treatment setting.
Nilotinib is PBS-subsidised for chronic and accelerated phase CML in the second-line
setting. Nilotinib is not approved for patients in blast crisis in any (first, second,
third-line) treatment setting.
Imatinib is not approved for second-line treatment of CML.
1. Initial second-line treatment
A patient will be able to be prescribed either dasatinib or nilotinib within the initial
18 month treatment period as second-line therapy, as long as only one agent is approved
at a time and providing the patient did not fail that drug as first-line therapy.
During the initial 18 month treatment period, switching between approved second-line
agents may only occur for reasons of intolerance, not failure of response.
2. Continuing treatment for second-line treatment
For continuing applications, patients must demonstrate response to PBS-subsidised
treatment as follows:
(i) within 18 months of the commencement of treatment, at which time patients in whom
a major cytogenetic response or peripheral blood BCR-ABL level of less than 1% on
the international scale (Blood 108:28-37,2006) has been demonstrated may receive authorisation
for a further 12 months of treatment; and
(ii) at no greater than 12 month intervals thereafter, to demonstrate that the major
cytogenetic response or peripheral blood BCR-ABL level of less than 1% has been sustained.
All pathology reports must be documented in the patient's medical records.
During second line continuing treatment beyond the initial 18 month treatment period,
switching between approved second line TKI agents may only occur for reason of intolerance.
Where there is failure of response, switching may only occur through application for
prescription of a third line agent.
3. Authority approval requirements
Response criteria to initial treatment with dasatinib or nilotinib:
For the purposes of assessing response to PBS-subsidised treatment with dasatinib
or nilotinib, either cytogenetic analysis indicating the number of Philadelphia positive
[t (9;22)] cells in the bone marrow measured by standard karyotyping, or quantitative
PCR indicating the relative level of BCR-ABL transcript in the peripheral blood using
the international scale, must be conducted and the results must be documented in the
patient's medical records. For bone marrow analyses, where the standard karyotyping
is not informative for technical reasons, a cytogenetic analysis performed on the
bone marrow by the use of fluorescence in situ hybridisation (FISH) with BCR-ABL specific
probe must be conducted and the results must be documented in the patient's medical
records. The cytogenetic or peripheral blood quantitative PCR analyses must be conducted
and the results must be documented in the patient's medical records within 18 months
of the commencement of treatment with dasatinib or nilotinib (patients in whom a major
cytogenetic response or peripheral blood BCR-ABL level of less than 1% is demonstrable
by 18 months are eligible to receive continuing treatment with that agent).
4. Definitions of response
A major cytogenetic response is defined as less than 35% Philadelphia positive bone
marrow cells. A peripheral blood BCR-ABL level of less than 1% on the international
scale (Blood 108: 28-37, 2006) also indicates a response, at least the biological
equivalent of a major cytogenetic response.
5. Definitions of loss of response
Loss of a previously documented major cytogenetic response (demonstrated by the presence
of greater than 35% Ph positive cells on bone marrow biopsy), during ongoing tyrosine
kinase inhibitor (TKI) therapy. Loss of a previously demonstrated molecular response
(demonstrated by peripheral blood BCR-ABL levels increasing consecutively in value
by at least 5 fold to a level of greater than 0.1% confirmed on a subsequent test),
during ongoing tyrosine kinase inhibitor therapy.