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At the time of writing, temozolomide remains unfunded in NZ
for any indication. This led to the recent patient protest outside parliament on
15 November 2005 calling for an accelerated process to provide funding through
PHARMAC and to bring NZ into alignment with Australia. The Pharmacology and
Therapeutics Advisory Committee (PTAC) was considering the application for
funding at a meeting on 17 November 2005.
The evidence for efficacy of first line temozolomide is
strong, being based on a large randomised controlled phase III trial. The
results reported are also similar to previously reported phase II data. The
results available however extend only to 2 years from treatment. Although 26% of
treated patients are alive at 2 years, only 10.7% are progression-free.
Unlike most cancers, brain tumours can affect patients of
any age and are the second most common tumour in children after leukaemias. GBM
however occurs in a minority of paediatric patients. It is, however, the
commonest histology in adult brain tumours.
As a clinician treating patients with brain tumours I wish
to be able to offer them the best standard treatment available. Aggressive
treatment is not necessarily appropriate for all patients, but applying similar
criteria to those used in the New England
Journal of Medicine study, patients with a good functional status
following surgery and a “good” quality of life are most likely to
benefit from the addition of temozolomide to radiation therapy.
In discussing therapeutic options with patients, the Health
& Disability Commissioner has ruled that this should include options not
necessarily available in the treating centre, or even in NZ.
“Standard” treatment therefore has to include world standards.
Patients confronted with this disease and its dreadful prognosis make extensive
use of the Internet looking for treatments that offer hope of benefit.
In the absence of a validated, subsidised therapy, they may
look at other more anecdotal and potentially harmful regimens.
This raises the economic question of what value does NZ
society place on the prolongation of survival, probably of the order of
magnitude of a few months for patients with an effectively incurable
disease.
Assuming 100 patients diagnosed with GBM in NZ per annum,
and that only 50 are fit enough to undergo combined modality therapy, the
additional annual drug cost for temozolomide (not including the necessary
anti-emetics and prophylactic antibiotics) would be $2,675,000.00. In clinical
outcomes, this would lead to an additional 8 patients alive at 2 years, at an
effective cost of $334,375 per patient.
In NZ, PHARMAC is charged with containing the cost of the
pharmaceutical budget. Any new therapy has to “compete” with others
for funding from a limited budget. Something else has to give to enable a new
therapy to be subsidised. In the case of management of newly diagnosed GBM, this
is effectively a new treatment, and does not replace any prior component of
treatment. Without an increase in the overall pharmaceutical budget, it is
difficult to see how temozolomide will secure funding.
Unfortunately, brain tumour therapy is only an example of a
common issue in oncology practice where new drugs used in addition to existing
regimens add to survival at defined time points in a statistically significant
way at a cost commonly around $60,000 to $100,000 per patient treated. With
absolute gains in survival of 3%–10% this may cost one million dollars per
additional patient alive.
Statistics and health economics are however very difficult
concepts for the individual wishing to have the best therapy possible.
Ultimately, politicians will decide where NZ stands in the
world rankings of contemporary medicine, and what offers the best health return
from a constrained budget.
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