 
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Journal of the New Zealand Medical Association,
10-March-2006, Vol 119 No 1230
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
PHARMAC responds on agents to prevent osteoporotic
fractures
In this issue of the
Journal, Dr Nigel Gilchrist (http://www.nzma.org.nz/journal/119-1230/1885)
summarises the funding of some medicines that reduce the incidence of
osteoporotic fractures. We believe that the current access criteria for
alendronate in the treatment of osteoporosis now has the potential to confer
considerable population health gains, and that past criteria targeted
alendronate so that other areas of health gain were not jeopardised. Discussions
with the supplier over raloxifene and PTH are ongoing.
AlendronateIn addition to the other evidence cited for bisphosphonates,
the currently-funded bisphosphonates etidronate and alendronate have been shown
to halve vertebral fractures (etidronate) and both vertebral and non-vertebral
fractures (alendronate) for women with established osteoporosis.1–3
We agree that the challenge now is for clinicians to ensure
those patients at need now are identified and receive treatment, including falls
prevention. Currently there are perhaps 46,000 patients using alendronate or
etidronate,4 when some 107,000 probably meet the new criteria for alendronate5
(see Figure 1).
The funding of alendronate in the late 1990s for
osteoporosis was hampered by its high cost at the time. This translated to an
estimated cost of $41,000 per quality-adjusted life year (QALY) and potentially
up to $37 million annual cost for the overall target population that was
advocated [being women average age 70 years with severe (established)
osteoporosis*]. The cost-effectiveness estimate was modelled on a baseline
incidence of 3.4% clinically significant hip, wrist or vertebral factures per
year, reducing to 1.7% with alendronate—an absolute risk reduction of 1.7%
per annum. This compared poorly with other medicine funding options PHARMAC
faced at the time.6
* i.e. i.e. bone mineralisation density (BMD) ≥
2.5 standard deviations (SDs) below the mean value in young adults (i.e. a
T-score < -2.5 SDs) and one or more previous fragility fracture(s)
Figure 1.
 However, for the potential 10,200 patients with very severe
osteoporosis [i.e. very low BMD (T-score < -3.0 SDs) and 2+ fragility
fractures], funded from February 2000, alendronate’s cost-effectiveness,
estimated at $3,500 per QALY, was much more favourable. This figure reflected
both the greater QALY gains and the hospitalisation and disability support
savings elsewhere to the health sector for these patients with higher baseline
fracture risks.7 Extending access in April 2001 by relaxing the previous
fracture requirement [i.e. T-score < -3.0 SDs and 1+ fragility fractures] had
an estimated cost/QALY of $12,400 for a further potential 22,800
patients.8
Full details of PHARMAC’s cost-effectiveness analysis
at the time can be found at http://www.nzma.org.nz/journal/119-1230/1895/PHARMACTAR9(1999).pdf.9
Under the current (October 2005) extended access criteria
for alendronate, described by Dr Gilchrist, PHARMAC’s preliminary analysis
estimated the weighted average cost-effectiveness of widening access to be
$1,000 per QALY for fracture risk. This compared well with other medicine
funding options available to PHARMAC at the time of the decision. Further
details of PHARMAC’s analysis can be found at http://www.nzma.org.nz/journal/119-1230/1895/PHARMACTAR70(2005).pdf.10
Cost-effectiveness estimates are highly sensitive to the
baseline risks of fragility fracture, which in turn vary widely according to
BMD, previous fracture history and particularly age11—where alendronate
becomes less cost-effective in younger age-groups.
By including patients without any previous fragility
fracture (but with BMD T-score <- 3.0 SDs), New Zealand’s access
arrangements for alendronate for the prevention of osteoporosis are now wider
that those of Australia.12
Raloxifene and PTHPTAC considered an application for raloxifene to be listed
under the same criteria as for alendronate in November 2005. The committee
recommended that the application, as presented by the supplier, be declined.
PTAC did however consider that raloxifene should be listed on the Pharmaceutical
Schedule with a high priority for patients intolerant of
bisphosphonates.13
Following the widening of access to alendronate last October
(which until then had been PHARMAC’s priority), and the partly positive
recommendation from PTAC for raloxifene, PHARMAC entered into renewed
negotiations with Eli Lilly for osteoporosis treatments. We will keep
prescribers informed of developments.
PHARMAC is currently funding PTH for two patients under the
Exceptional Circumstances scheme. Any proposal for listing PTH on the
Pharmaceutical Schedule would need to be targeted to those who would gain most
benefit and weighed up against competing medicines.
CommentIn response to some of Dr Gilchrist’s specific points,
calcitriol was not funded specifically for osteoporosis, and PTAC does not
conduct cost utility analyses.
The 1997 recommendations by PTAC and its Osteoporosis
Treatments Subcommittee, that alendronate be subsidised for established
osteoporosis, need to be placed in context. Both committees considered, at the
time (pre-WHI), that hormone replacement therapy (HRT) should be used ahead of
alendronate, and that alendronate should only be subsidised for women where HRT
was contraindicated or who experienced significant adverse effects after a trial
of HRT.14,15 The Subcommittee had universally agreed that HRT should be used
first line and was the preferred treatment based on efficacy, costs and
additional benefits in areas other than fractures.15
PHARMAC’s decision criteria (http://www.pharmac.govt.nz/pdf/opps.pdf)
require the consideration of clinical effectiveness, along with
cost-effectiveness and seven other criteria. This occurred with PHARMAC’s
decisions during 1999 to 2001, as it did with the 2005 decision. There is never
any temptation to do otherwise – be it with a new chemical entity, or a
clinically effective older generic medicine.
PHARMAC’s rigour and objectiveness are not new-found.
The 1999 technology assessment9 complied with, yet predated, the formal polices
for PHARMAC’s economic analyses16 and guidelines for clinical evidence.17
Neither PTAC’s assessment nor the PHARMAC Board’s decision-making
processes have changed over that time. What does change is a medicine’s
place in therapy, its price, the total forecast funds available, and competing
areas of health gain from other medicines – all of which affect funding
priorities.
Scott Metcalfe
Public Health Physician Wellington Tommy
Wilkinson
Therapeutic Group Manager Intern PHARMAC Wellington Dilky Rasiah
Acting Medical Director PHARMAC Wellington Conflict of
interest: Scott Metcalfe is externally contracted to work with PHARMAC
for public health advice. He wrote both the 1999 and the 2005 Technology
Assessment Reports for alendronate,9,10
the ‘Recommended methods to derive clinical inputs for proposals to
PHARMAC’,17 and co-wrote the 1999 version of PHARMAC’s Prescription
for Pharmacoeconomics.16 Tommy Wilkinson and Dilky Rasiah declare no
conflicts.
References and
Endnotes:
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | Current
issue | Search journal |
Archived issues | Classifieds
| Hotline (free ads) Subscribe | Contribute | Advertise | Contact Us | Copyright | Other Journals |
|