Civil society strategy for the compulsory licensing of lopinavir/ritonavir: the Brazilian case

The flexibilities in the TRIPS Agreement (Trade Related Aspects of Intellectual Property) have been very useful in lowering the prices of antiretrovirals (ARVs) in Brazil. In this article, based on several presentations made at the conference, Marcela Fogaça Vieira et al describe recent developments in Brazil, including the granting of a compulsory licence for efavirenz.

Potential risks and benefits of HIV treatment simplification: a simulation model of a proposed clinical trial

BACKGROUND

In recent studies, subjects who had achieved suppression of the human immunodeficiency virus (HIV) RNA level while receiving an initial 3-drug antiretroviral regimen successfully maintained suppression while receiving treatment with a "boosted" protease inhibitor (PI) alone. We projected the long-term outcomes of this treatment simplification strategy to inform the design of a proposed multicenter, randomized clinical trial.

METHODS

We used published studies to estimate the efficacy, adverse effects, and cost of a sequence of HIV drug regimens for the simplification strategy, compared with those outcomes for the current standard-of-care (SOC) strategy. Using a published simulation model of HIV disease, we projected life expectancy, discounted quality-adjusted life expectancy (QALE), and discounted lifetime medical costs for each strategy.

RESULTS

Subjects who have not developed PI-resistant HIV infection at the time of failure of the simplification regimen have a greater life expectancy (27.9 vs. 27.1 years) and QALE (14.9 vs. 14.7 years), compared with SOC subjects, because they receive an additional line of therapy without negative consequences for future treatment options. The QALE for the simplification strategy remains higher than that for the SOC, unless a large proportion of patients experiencing virologic failure while receiving the simplification regimen develop PI resistance. Depending on the probability of simplification regimen failure, the advantage is maintained even if HIV develops PI resistance in 42%-70% of subjects. Projected lifetime costs are $26,500-$72,400 per person lower for the simplification strategy than for the SOC strategy.

CONCLUSIONS

An HIV treatment simplification strategy involving use of a boosted PI alone may lead to longer survival overall at lower cost, compared with the SOC combination therapy, because the simplification strategy potentially adds an additional line of therapy. The risk of emergence of PI resistance during treatment with a simplified regimen is a critical determinant of the viability of this strategy.

Predicting HIV care costs using CD4 counts from clinical trials

OBJECTIVE

To predict the effects of a new antiretroviral agent on the costs of care in a US HIV care setting.

METHODS

Recent data on costs of patient care by CD4 count from 2 US cohorts (the HIV Research Network cohort and patients receiving primary care at the University of Alabama at Birmingham HIV clinic) were combined with CD4 count data from the POWER trials of the protease inhibitor darunavir. Patients in the POWER trials received either darunavir plus low-dose ritonavir (darunavir/r) or selected control protease inhibitors. The effects of rising CD4 counts with darunavir/r 600/100 mg twice daily on healthcare costs were predicted by using the US cohort data and published US antiretroviral drug prices.

RESULTS

In the POWER trials, the overall cost of antiretroviral treatment including darunavir/r was $427 (1.4%) higher than that of combination treatment including control protease inhibitors. However, this increase may be offset by lower predicted costs of HIV care, leading to predicted net savings in overall costs of HIV treatment and care of $3613 per person-year based on data from the HIV Research Network cohort and $2836 per person-year based on data from the University of Alabama cohort. The prediction of cost savings is limited to the 12-month duration of the trial.

CONCLUSION

By raising the CD4 count, new antiretrovirals could lower healthcare costs for HIV-infected people. This type of analysis could be used for other antiretrovirals, for a short-term assessment of overall budget impact.

Cost effectiveness of lopinavir/ritonavir compared with atazanavir plus ritonavir in antiretroviral-experienced patients in the US

OBJECTIVE

To estimate the cost effectiveness and long-term combined effects of HIV disease and antiretroviral (ARV) therapy-related risk for coronary heart disease (CHD) on quality-adjusted survival and healthcare costs for ARV-experienced patients.

METHODS

A previously validated Markov model was updated and supplemented with the Framingham CHD risk equation. The representative patient in the model was male, aged 37 years and had a baseline 10-year CHD risk of 4.6%. Patients started with either lopinavir/ritonavir (LPV/r) or ritonavir-boosted atazanavir (ATV+RTV) as the protease inhibitor (PI). The proportions of patients with viral suppression below 400 and 50 copies/mL, respectively, at week 48 reported in clinical trials were used to estimate the differences between these two therapies. The daily ARV costs were $US 24.60 for LPV/r capsules (2005 costs) and $US 26.54 for LPV/r tablets (2006 costs), $US 29.76 for ATV and $US 8.57 for ritonavir (2005 costs). Costs of other ARV drugs were taken from average wholesale drug reports for 2005. The cost of AIDS events was estimated from Medicaid billing databases and reflected a medical care system perspective and 2005 treatment costs. Cost-effectiveness calculations assumed a lifetime time horizon. The effects of different model assumptions were tested in a multiway sensitivity analysis by combining extreme values of parameters.

RESULTS

The model estimated a clinical and economic advantage to using LPV/r over ATV+RTV, which varied depending upon the use of LPV/r capsules or tablets. Using LPV/r capsules was comparatively beneficial for ARV-experienced patients in quality-adjusted life-months (QALMs) of 4.6 (corrected for differences in CHD risk) compared with ATV+RTV. In addition, there were 5- and 10-year overall per-patient cost savings of $US 17,995 and $US 21,298, respectively. Estimates for the LPV/r tablet formulation approved in 2005 (assuming similar efficacy) improved cost savings over 5- and 10-year periods to $US 19,598 and $US 23,126 per patient, respectively, because of a drug price differential. Sensitivity analysis tested numerous assumptions about the model cost and efficacy parameters and found that the results were robust to most changes. Model limitations were the uncertainty associated with the model parameters used.

CONCLUSION

LPV/r appears to be a highly cost-effective regimen relative to ATV+RTV for the treatment of HIV. The long-term CHD risk associated with LPV/r was minimal compared with the increased risk of AIDS/death and costs projected for a less efficacious PI-based regimen.

Cost effectiveness of lopinavir/ritonavir compared with atazanavir in antiretroviral-naive patients: modelling the combined effects of HIV and heart disease

BACKGROUND AND OBJECTIVE

The choice of initial highly active antiretroviral therapy (HAART) should take into account the need to balance efficacy, adverse event risk, resistance concerns for the treatment of HIV and treatment costs. Increased risk of coronary heart disease (CHD) may be of special concern in the selection of HAART therapy, because differences in potential CHD risk have been reported for different regimens. This study aimed to estimate the long-term combined effects of HIV disease and antiretroviral (ARV)-related risk for CHD on quality-adjusted survival and healthcare costs for ARV-naive patients.

METHODS

A previously validated Markov model was updated and supplemented with the Framingham CHD risk equation. In the model, the average patient was male, aged 37 years and had a baseline 10-year CHD risk of 4.6%. Patients started with either lopinavir/ritonavir or unboosted atazanavir as the first protease inhibitor (PI). Clinical trial data were used to estimate the differences between these two therapies. The daily PI costs were $US18.52 for lopinavir/ritonavir and $US22.08 for atazanavir. Other costs were estimated from Medicaid billing databases and average wholesale drug price reports. All model costs were reported as the 2004 present value in US currency. The model's time horizon reflected a patient's lifetime, and the perspective of the analysis was that of the healthcare system and did not include indirect costs in the model cost estimates. Various CHD risk levels were tested in the sensitivity analysis.

RESULTS

In the base case, the model predicted a median duration of initial PI regimen of 5.6 years for lopinavir/ritonavir and 3.8 years for atazanavir. Over 10 years, patients who started on atazanavir had 30 additional AIDS events per 100 patients. Only 0.7 additional CHD events per 100 patients occurred for those who started on lopinavir/ritonavir. The model estimated 10-year total healthcare cost savings of $US12,543 per patient in the lopinavir/ritonavir group. The lifetime incremental cost effectiveness of lopinavir/ritonavir versus atazanavir was $US6797 per quality-adjusted life-year gained.

CONCLUSION

Lopinavir/ritonavir is a highly cost-effective regimen relative to atazanavir for the treatment of HIV. The effect of lopinavir/ritonavir on long-term CHD risk was minimal compared with the increased risk of AIDS/death projected for a less efficacious first PI regimen. The cost of lipid-lowering drugs and treatment of CHD for patients taking the lopinavir/ritonavir regimen was only 1.2% of the cost of AIDS care per person, which was too small to have a significant effect on the overall cost savings with lopinavir/ritonavir therapy. Thus, a decision to forgo potency and durability in an ARV regimen for an ARV-naive patient in favour of a less potent regimen with an improved lipid profile may prove to be costly over time, in terms of both budget impact and life expectancy.

HIV drug resistance surveillance for prioritizing treatment in resource-limited settings

BACKGROUND

Sentinel testing programs for HIV drug resistance in resource-limited settings can inform policy on antiretroviral therapy (ART) and drug sequencing.

OBJECTIVE

: To examine the value of resistance surveillance in influencing recommendations toward effective and cost-effective sequencing of ART regimens.

METHODS

A state-transition model of HIV infection was adapted to simulate clinical care in Côte d'Ivoire and evaluate the incremental cost-effectiveness of (1) no ART; (2) ART beginning with a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen followed by a boosted protease inhibitor (PI)-based regimen; and (3) ART beginning with a boosted PI-based regimen followed by an NNRTI-based regimen.

RESULTS

At a 5% prevalence of NNRTI resistance, a strategy that started with a PI-based regimen had a smaller health benefit and higher cost-effectiveness ratio than a strategy that started with an NNRTI-based regimen (cost-effectiveness ratio $910/year of life saved). Results consistently favored initiation with an NNRTI-based regimen, regardless of the population prevalence of NNRTI resistance (up to 76%) and the efficacy of an NNRTI-based regimen in the setting of resistance. The most influential parameters on the cost-effectiveness of sequencing strategies were boosted PI-based regimen costs and the efficacy of this regimen when used as second-line therapy.

CONCLUSIONS

Drug costs and treatment efficacies, but not NNRTI resistance levels, were most influential in determining optimal HIV drug sequencing in Côte d'Ivoire. Results of surveillance for NNRTI resistance should not be used as a major guide to treatment policy in resource-limited settings.

[Pharmacoeconomic analysis of a maintenance strategy with lopinavir/ritonavir monotherapy in HIV-infected patients]

AIMS

To conduct a cost-efficacy analysis of lopinavir/ritonavir (LPV/r) monotherapy as a maintenance regimen following induction of virological response with triple therapy including LPV/r. The pharmacoeconomic analysis was performed from the perspective of the Spanish public health system.

METHODS

A cost-efficacy analysis was performed in a phase IV-II, comparative, randomized, multicenter, open-label clinical trial evaluating the efficacy and safety of maintenance therapy with LPV/r monotherapy versus continuation of triple therapy in HIV-infected patients with a persistently undetectable viral load for 6 months. For the pharmacoeconomic analysis, efficacy was defined as the proportion of patients with plasma HIV RNA concentrations < 50 copies/mL at 48 weeks from the start of the study. An intent-to-treat analysis was performed. Only direct costs were considered. Cost, efficacy and the cost-efficacy ratio were calculated for each treatment option.

RESULTS

The cost-efficacy ratio of LPV/r maintenance monotherapy was 5186 euros per unit of achieved effect (patient with plasma HIV RNA concentrations < 50 copies/mL at 48 weeks), whereas maintenance with triple therapy had a cost-efficacy ratio of 8688 euros per unit of achieved effect.

CONCLUSION

The option of LPV/r monotherapy as maintenance therapy in HIV-infected patients following induction of virological response with triple therapy including LPV/r might be a more efficient alternative than maintaining triple therapy, as evidenced by a more favorable cost-efficacy ratio.

Effects of the ritonavir price increase on the cost of protease inhibitor regimens in United States

In late 2003, one manufacturer effected a fivefold increase in the price of its protease inhibitor (PI) ritonavir. Using the average wholesale price of each treatment regimen, IMS Health marketshare data, and epidemiologic data, the authors analyzed the effect of this price increase on the direct cost of ritonavir-boosted PI regimens. If 75% of individuals living with acquired immunodeficiency syndrome and 50% of those with human immunodeficiency virus infection in 2003 were receiving PI regimens, the total direct cost after the price rise was dollar 4 billion, an increase approaching dollar 1 billion. Moreover, the estimates of increased costs obtained in this study are assumed to be conservative.

Economic impact of antiretroviral therapy prescription decisions in the context of rapid scaling-up of access to treatment: lessons from Mexico

BACKGROUND

Mexico started scaling-up access to antiretroviral treatment in the late 1990s. Even though the Mexican Health System enrolled patients at impressive speed, in the initial years important aspects of the quality of care were overlooked.

OBJECTIVE

To describe antiretroviral prescribing and adherence practices in Mexico during initial scaling-up of antiretroviral treatment in comparison to national treatment guidelines and to estimate the associated economic cost.

METHODS

Eleven public sector hospitals provided detailed patient chart data. Monthly observations formed the basis of scenarios aligned by calendar month and by month before and after initiation of triple therapy. The scenarios varied by extent of prescription refill, adherence levels, and compliance with national treatment guidelines.

RESULTS

Antiretroviral therapy prescription practices were largely inconsistent with published guidelines. Non-recommended combinations were prescribed to between 54 and 79% patients-months per year. Additionally, more than 50% of patients experienced four to 13 changes in treatment. Modeling of the economic impact of treatment practices showed that it would have been possible to effectively treat the same number of patients at the same or lower cost per patient.

CONCLUSIONS

In addition to dispensing drugs, countries scaling-up antiretroviral therapy must find ways to ensure consistent drug supply, appropriate prescription practices and effective levels of adherence. Failing to do so will seriously reduce treatment effectiveness, greatly increasing the cost per unit of health benefit. With very low levels of effective adherence patients may even be harmed and the spread of multi-drug resistant virus facilitated.

Prezista (darunavir, TMC-114) approved; may be important treatment advance

A major new antiretroviral has been approved, for patients resistant to more than one protease inhibitor. There is no information yet on risk/benefit compared to standard treatments for first-line use. Tibotec, which developed the drug and is now part of Johnson & Johnson, showed price restraint and avoided setting a new record high price, which other companies have done.

Patient characteristics and costs associated with dyslipidaemia and related conditions in HIV-infected patients: a retrospective cohort study

BACKGROUND

Metabolic abnormalities are common in HIV-infected individuals and, although multifactorial in origin, have been strongly associated with antiretroviral therapy.

METHODS

Using automated claims and clinical databases, combined with medical record data, we evaluated the burden of dyslipidaemia (DYS) and associated metabolic abnormalities among a cohort of 900 HIV-infected patients aged 18 years and older who received their care from a large multispecialty medical group between 1 January 1996 and 30 June 2002. A Cox proportional hazards model for DYS was developed. Resource use was compiled and subsequently costed with stratification to account for variable length of follow-up.

RESULTS

Mean follow-up time was 3.3 years. DYS was present in 54% of the cohort and 3.4% experienced a cardiovascular (CV) event. Both unadjusted and adjusted results found patients with dyslipidaemia and cardiovascular events significantly more likely to have received protease inhibitor (PI) treatment for longer periods of time. In the Cox proportional hazards model the following factors were significantly associated with an increased risk for DYS: older age, white race, PI use and male sex. Diagnoses of hypertension, hepatitis C virus infection, depression or opportunistic infections were all negatively associated with a DYS diagnosis. When controlled for length of follow up, patients with DYS (and no CV-related events) incurred greater median and mean total average costs than patients without DYS or CV-related events. For patients with more than 2 years of follow up, these total cost differences were statistically significant (P<0.05).

CONCLUSIONS

These findings indicate that DYS is common among patients with HIV infection and is associated with increased use of medical resources.