sábado, abril 29, 2006
Custos de ARVs no Reino Unido
Cost of treatment and care becoming sensitive issue for UK as NHS faces spending slow-down
Funding problems for the NHS have rarely been out of the news this year, so it comes as no surprise that the cost of HIV treatment and care was mentioned in just about every session at the Twelfth Annual Conference of the British HIV Association, held in Brighton between March 30th and April 1st.
As the National Health Service struggles to cope with instructions from the Department of Health that budget deficits must be contained, and that over-spending trusts will not be bailed out, commissioners of HIV care within primary care trusts are forcing clinicians to pay increasing attention to the cost of the antiretrovirals that they are prescribing.
In addition the pace of growth in NHS spending is set to slow over the next few years, requiring further hard choices within the system, and in an editorial due to appear in the British Medical Journal on Friday, Professor Alan Maynard of York University's Departmeent of Health Sciences argues that the National Institute of Clinical Excellence, by approving technologies and drugs of marginal cost-effectiveness, has inflated NHS spending. NICE needs to be more stringent, he argues, and should have the power to negotiate prices with drug companies. He highlights recent proposals from health economists that NICE should reduce its threshold for cost-effectiveness from £30,000 per quality adjusted life year saved (QALY) to £15,000 per QALY, a level at which some aspects of HIV care as currently priced wouyld be under threat in the UK.
Various studies looking at the cost-effectiveness of particular antiretroviral drugs and regimens have been conducted, often with unrestricted financial backing from drug companies. Although these studies often appear to show that one antiretroviral drug is cheaper than others, they tend to look only at the raw costs of treatment, and do not take into account other potential benefits and risks associated with treatment such as side-effects and the cost of their treatment, the risk of resistance and the further cost implications of this, and the quality of life -implications of side-effects.
Nevirapine – cheap and effective
Dr Anton Pozniak told the Boehringer Ingelheim satellite session at last month's BHIVA conference how the appropriate use of the non-nucleoside reverse transcriptase inhibitor (NNRTI) in first-line therapy would not compromise potency or safety, and could save HIV clinics substantial amounts of cash. Data were presented from the 2NN study showing that nevirapine (Viramune) is as potent as its competitor NNRTI, efavirenz (Sustiva), can be safely dosed once a day, and that skin rash and hepatic toxicity, its main and most concerning side-effects, can be avoided if the “black box” warning regarding its prescription to individuals with higher CD4 cell counts (400 cells/mm3 for men and 250 cells/mm3 for women) were observed.
Combivir - not perfect, but a good and cheap drug and in 2006, cheap matters
In a balloon debate in the GSK satellite on the virtues of fixed dose nucleoside/nucleotide backbones of first-line therapy, Dr Nelson emphasised that Combivir was significantly cheaper than its competitor backbone combination pills Kixeva and Truvada. He acknowledged that Combivir (which includes AZT and 3TC) did have limitations compared to the two alternative combination pills, including twice-daily dosing and the risk of lipoatrophy from AZT. However, he said that cost may mean a choice between the best, but most expensive treatment and very good, but cheaper options, adding that cost was a factor that no clinic could ignore in 2006.
It’s perhaps worth noting that the 2005 treatment guidelines of the British HIV Association caution against the use of AZT and AZT-containing products (such as Combivir) in first-line therapy because of the risk of lipoatrophy, and also recommend that people already taking AZT or AZT-containing products should have this risk explained to them and be offered the opportunity to switch to an alternative drug.
T-20 – cost-effective, but evidence that not being prescribed on grounds of cost
T-20, the only injectable antiretroviral has been licensed for use in people with extensive experience of antiretroviral therapy since 2004, however its manufacturer Roche, and some UK HIV physicians have expressed concern that the drug is being under-used in the UK and that patients who may benefit from its use are not being offered it because doctors over-estimate their patients' reluctance to use it.
Cost also featured in the Roche satellite, when Dr Mike Youle mentioned that the use of the most expensive antiretroviral, the fusion inhibitor T-20 (enfuvirtide, Fuzeon) was cost-effective, but drew attention to evidence that at least one HIV pharmacy in the UK had refused to prescribe it on grounds of cost and suggested that fears about price and “laziness” meant that doctors were often not prescribing the drug to patients with very limited treatment options who could benefit from it.
Cost and durability of first-line treatment
Research was also presented to the conference looking at the cost of first, second and third-line antiretroviral combinations, showing that the median duration of first-line treatment was seven years, costing approximately £112,000 per patient and that second- and third-line therapy each lasted for a median of four years each costing in the region of £70,000.
Protease inhibitors and NNRTIs cost-effectiveness in first-line therapy compared
In a separate study, presented as a poster to the conference, investigators looked at the cost-effectiveness of NNRTI versus protease inhibitor-containing first-line treatment used between 1996 and 2002 at UK HIV clinics. They estimated cost-effectiveness per life year gained. The study was funded by an unrestricted educational grant by the drug companies Gilead Sciences, who make tenofovir (Viread) and FTC (emtricitabine, Emtriva) which are also available in the combination pill Truvada, and Boehringer Ingleheim, manufacturers of nevirapine (Viramune) and tipranavir (Aptivus).
A total of 3,647 patients taking first-line antiretroviral therapy were included in their analysis. They found that individuals taking first-therapy including an NNRTI had the longest estimated time to treatment failure and the lowest annual hospital costs compared to protease inhibitor, or boosted protease inhibitor-containing regimens.
“Given the increasing number of people living with HIV and their increasing life span from time of infection, cost and cost-effectiveness of regimens are becoming important criteria for deciding which particular regimen to use for first-line HAART”, conclude the investigators.
Cost of salvage regimens also explored
It’s not just first-line therapy where cost is an issue. Another poster presentation to the conference looked at the relative costs of different late salvage regimens. In particular investigators calculated the costs per patient of achieving an increase in CD4 cell count of at least 25 cells/mm3, a 0.5 log10 reduction in viral load, or a reduction in viral load to below 50 copies/ml. Eleven separate clinical trials involving 4,000 heavily treatment-experienced patients were analysed. The study was conducted by investigators at the Royal Free Hospital in London, the University of Liverpool and the pharmaceutical company Tibotec, the manufacturer of the experimental protease inhibitor TMC114.
The cost of achieving a reduction of 0.5 log10 in viral load varied from £733 per patient with TMC114 boosted by ritonavir with optimised background (the POWER studies) to £10,385 for T-20 plus optimised background (TORO-1). The cost of achieving a 25 cell/mm3 increase in CD4 cell count also varied widely, from £1,276 for TMC114/ritonavir and optimised background in the POWER studies to £28,929 for T-20 plus optimised background in the TORO-2 study.
The NAM Clinical Symposium on May 25th is concerned with optimising HIV care and will include an analysis of how issues such as cost may impact on patient care in the future. To download an application form for a free place click here.