Docetaxel with prednisone or prednisolone for the treatment of ...

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Economic review
TABLE 20 Summary of cost-effectiveness
Intervention Mean costs (CAN$) Mean quality- ICER
adjusted weeks
M + P 27,300 41.5
P 29,000 28.2
Incremental –1,700 13.3 M + P dominates P
M, mitoxantrone; P, prednisone.
Comments
The economic analysis is based on patient-level
data from CCI-NOV22, and as such the results are
likely to have good internal validity. However, the
study does suffer from some potential limitations
which affect its applicability for healthcare
decision-making within the NHS. First, it is
unclear how generalisable the results are to the
NHS setting. The study was undertaken in Canada
using Canadian practice patterns and the authors
suggest that the results should only be generalised
to similar healthcare systems. In addition, the
report presents total costs per category with no
separation between the unit costs and resource
use. This further limits the transfer of the results
to NHS practice. Second, the analysis undertaken
within the study only considers the comparison of
mitoxantrone plus prednisone with
prednisone/prednisolone alone. Therefore, the
analysis ignores other chemotherapies that are
potentially relevant to the NHS (i.e. docetaxel and
estramustine). Finally, the valuation of benefit
undertaken within the analysis involved translating
measures of QoL obtained from patient completed
questionnaires into a proxy rating scale and then
to utilities via a published equation. This does not
conform to the requirements of the NICE
reference case, which recommend societal
valuations obtained using a standardised and
validated generic instrument.
Company submissions
Review of Sanofi-Aventis (2005). 61
Sponsor submission to the National
Institute for Health and Clinical
Excellence: Taxotere ® (docetaxel) in
Metastatic Hormone-refractory
Prostate Cancer (mHRPC)
Overview
The economic analysis in the submission by
Sanofi-Aventis evaluated the cost-effectiveness of
docetaxel plus prednisone (3-weekly regimen)
compared with mitoxantrone plus prednisone.
The evaluation was based on an analysis of
patient-level data derived from prospective
collection of resource use and patient outcome
data from the TAX 327 clinical trial. Although
TAX 327 included two alternative docetaxel
regimens (3-weekly and weekly administration),
only the 3-weekly regimen was considered in
the cost-effectiveness analysis due to current
licensing.
The analysis was undertaken from an NHS
perspective. Overall costs were separated into two
main elements: the first-line chemotherapy phase
(comprising the drug acquisition costs, costs of
administration and hospitalisations for adverse
events) and the follow-up phase (including
subsequent chemotherapy, palliative therapies and
hospitalisations). The primary outcome for the
cost-effectiveness analysis was life-years gained
based on a comparison of overall survival in the
different intervention groups. Separate life-years
gained estimates were provided based on a withintrial
comparison (using median survival data) and
a lifetime comparison (using mean survival data).
The lifetime comparison was based on an
extrapolation approach using parametric survival
analysis. Decision uncertainty was assessed using
simple deterministic sensitivity analysis.
A brief summary of the evaluation is provided in
Table 21. The key features are described in more
detail below.
Summary of effectiveness data
Survival estimates were based on patient-level data
from the TAX 327 trial. Two separate analyses
were undertaken: (1) a within-trial analysis – using
median survival estimates and (2) a lifetime analysis
– based on mean survival duration. In order to
estimate mean survival duration, it is necessary to
estimate the area under the entire survival curve.
In situations in which censoring exists, the survival
curves must be extrapolated beyond the observed
data to eliminate right censoring. Consequently, a
parametric survival model was fitted in order to
obtain an estimate of mean survival duration for
each of the two interventions.