The cost of antiretroviral drug resistance in HIV-positive patients

US cost-utility model of lenacapavir plus optimized background regimen (OBR) vs fostemsavir plus OBR and ibalizumab plus OBR for people with HIV with multidrug resistance

BACKGROUND

Heavily treatment-experienced (HTE) people with HIV (PWH) have limited treatment options owing to multidrug resistance (MDR). Lenacapavir (LEN) is indicated, in combination with other antiretrovirals, for the treatment of adults with MDR HIV-1 experiencing failure of their current antiretroviral regimen because of resistance, intolerance, or safety considerations.

OBJECTIVE

To evaluate the cost-utility of LEN in combination with an optimized background regimen (OBR) vs alternative recently approved treatments for HTE PWH, fostemsavir (FTR)+OBR and ibalizumab (IBA)+OBR, for the treatment of PWH with MDR, from a mixed US health care payer perspective.

METHODS

A Markov state-transition model with a lifetime time horizon was developed. Transition probabilities between viral load categories were based on individual participant data from the CAPELLA trial for LEN+OBR and on relative efficacy parameters obtained from indirect treatment comparisons for comparators. Health state utilities were sourced from the literature. Costs included drug acquisition costs, drug administration costs, disease management costs, adverse event costs, AIDS-related event costs, and treatment switching costs and were sourced from red book costs, Medicare and Medicaid fees, and the literature. Costs and outcomes were discounted at 3% annually. The model was used to estimate total and incremental costs, life-years (LYs), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. A deterministic and a probabilistic sensitivity analysis, as well as scenario analyses, were performed to address elements of uncertainty in the model and to explore the robustness of the results.

RESULTS

Over a lifetime time horizon, LEN+OBR was associated with the highest absolute QALYs (9.41) and the greatest number of LYs (12.09) compared with FTR+OBR (QALYs: 8.75; LYs: 11.26) and IBA+OBR (QALYs: 8.36; LYs: 10.78). LEN+OBR was also associated with the lowest total lifetime costs of the 3 interventions (LEN+OBR: $1,441,122 [US dollars]; FTR+OBR: $1,504,986; IBA+OBR: $1,524,396) and therefore was dominant over both comparators in the base case. LEN+OBR remained dominant vs FTR+OBR and IBA+OBR across the range of scenarios tested and LEN+OBR had a 99% probability of being cost-effective compared with FTR+OBR and IBA+OBR in the probabilistic sensitivity analysis at a willingness-to-pay threshold of $50,000/QALY.

CONCLUSIONS

This economic evaluation demonstrated that LEN+OBR provides meaningful increases in QALYs and LYs, and is dominant over a lifetime time horizon, compared with FTR+OBR and IBA+OBR for the treatment of PWH with MDR in the United States.

Estimating the cost due to resistance against antiretroviral therapies in individuals with HIV: Perspective of the Kingdom of Saudi Arabia

Objectives

The emergence of resistance to antiretroviral therapy (ART) has an impact on the cost of HIV care. This study aimed to estimate the direct and indirect costs associated with the first episode of drug resistance in individuals with HIV receiving first-line ART.

Methods

We developed a cost calculator to estimate the cost of drug resistance over a period of 12 months in the Kingdom of Saudi Arabia. The model inputs (estimated using expert opinion and publicly available sources) included costs associated with testing for resistance, adverse events of a new regimen, and indirect costs.

Results

The direct and indirect medical expenses for the year resistance developed were 6980 Saudi Arabian riyal (SAR) and SAR 2862, respectively. The addition of the cost of new ARTs would increase the total annual costs (between SAR 5174 and SAR 34,265 per patient). One-way sensitivity analysis also reported significant impact of initial and switching therapies used after resistance develops on the total costs of resistance per year.

Conclusions

There is a significant cost burden associated with drug resistance, which emphasizes the need to select an appropriate initial ART regimen that has a strong genetic barrier and conduct pre-treatment resistance tests (if possible).

Outcome Impacts Due to Pathogen-Specific Antimicrobial Resistance: A Narrative Review of Published Literature

Antimicrobial resistance (AMR) has become a global threat to not only public health impacts but also clinical and economic outcomes. During the past decades, there have been many studies focusing on surveillance, mechanisms, and diagnostics of AMR in infectious diseases but the impacts on public health, clinical and economic outcomes due to emergence of these AMRs are rarely studied and reported. This review was aimed to summarize the findings from published studies to report the outcome impacts due to AMR of malaria, tuberculosis and HIV and briefly discuss the implications for application to other infectious diseases. PubMed/Medline and Google Scholar databases were used for search of empirical and peer-reviewed papers reporting public health, clinical and economic outcomes due to AMR of malaria, tuberculosis and HIV. Papers published through 1 December 2019 were included in this review. A total of 76 studies were included for this review, including 16, 49 and 11 on public health, clinical and economic outcomes, respectively. The synthesized data indicated that the emergence and spread of AMR of malaria, tuberculosis and HIV have resulted in adverse public health, clinical and economic outcomes. AMR of malaria, tuberculosis and HIV results in significant adverse impacts on public health, clinical and economic outcomes. Evidence from this review suggests the needs to consider the similar studies for other infectious diseases.

The impact of drug coverage on viral suppression among people living with HIV in Ontario, Canada

OBJECTIVES

We investigated the effect of drug coverage on viral suppression (sVL) in Ontario, Canada, where there is no universal coverage of prescription drugs, including antiretroviral therapy (ART).

METHODS

Ontarians without employment coverage may be eligible for varying degrees of coverage through government-sponsored programs. Remaining individuals pay all expenses entirely out of pocket. Among participants on ART enrolled in the Ontario HIV Treatment Network Cohort Study (OCS) who were interviewed in 2008-2013 with known or imputable drug coverage, we estimated the prevalence with sVL (< 200 copies/mL) as of their last viral load each year. We calculated prevalence ratios (PR) according to time-updated socio-economic and behavioural factors using multivariable generalized estimating equations with a log-link function. Multiple imputation was used to assess the sensitivity of these findings to different assumed missing data models.

RESULTS

One thousand two hundred forty-seven participants were included (3463 person-years). Compared to study participants with employer coverage, individuals covered through the Ontario Drug Benefit (ODB) were less likely to be suppressed (PR, 95% confidence interval (CI) 0.96, 0.93-0.98). After multivariable adjustment, ODB remained independently associated with less success in achieving sVL (adjusted PR, 95% CI 0.98, 0.95-0.99). These findings were robust to different assumptions about the missing data.

CONCLUSION

Our findings suggest that drug coverage can affect viral suppression in our setting. Further research is needed to identify the mechanisms by which coverage interacts with individual patient factors to affect viral suppression. Mechanisms to improve access and coverage for ART are needed.

Risk Factors, Health Care Resource Utilization, and Costs Associated with Nonadherence to Antiretrovirals in Medicaid-Insured Patients with HIV

BACKGROUND

Adherence to antiretrovirals (ARVs) is critical to achieving durable virologic suppression.

OBJECTIVE

To investigate risk factors of poor adherence and the effect of suboptimal adherence on health care resource utilization (HCRU) and costs in Medicaid patients.

METHODS

A retrospective longitudinal study was conducted using Medicaid data. Adults (aged ≥ 18 years) with human immunodeficiency virus (HIV)-1 initiating selected ARVs (index date) were identified. Adherence was measured using medication possession ratio (MPR) and proportion of days covered (PDC) at 6 and 12 months post-index. Risk factors of poor adherence (PDC < 80%) were assessed using a logistic regression. HCRU and costs were compared between suboptimal (80% ≤ PDC < 95%) and optimal (PDC ≥ 95%) adherence groups using Poisson and ordinary least square models, respectively.

RESULTS

In total, 3,477 patients were identified. Using MPR, 1,282 (39.0%) of the evaluable patients had poor adherence; 667 (20.2%) had suboptimal adherence; and 1,342 (40.8%) had optimal adherence versus 1,342 (51.1%), 509 (19.0%), and 804 (30.0%), respectively, using PDC at 6 months. PDC at 12 months was even lower. Younger age (OR = 1.58; 95% CI = 1.18-2.11; P = 0.002), noncapitated coverage (OR = 1.40; 95% CI = 1.16-1.69; P < 0.001), dual Medicaid/Medicare coverage (OR = 5.98; 95% CI = 4.39-8.16; P < 0.001), no baseline ARV treatment (OR = 1.98; 95% CI = 1.62-2.41; P < 0.001), and baseline asymptomatic HIV (OR = 1.37; 95% CI = 1.13-1.68; P = 0.002) were associated with higher risk of poor adherence. Suboptimal adherence patients had higher total number of days spent in a hospital (incidence rate ratio [IRR] = 1.62; 95% CI = 1.13-2.19; P = 0.008), total number of long-term care admissions (IRR = 3.11; 95% CI = 1.26-7.39; P = 0.008), total medical costs (mean monthly cost difference = $339; 95% CI = $153-$536; P < 0.001), and inpatient costs (mean monthly cost difference = $259; 95% CI = $122-$418; P < 0.001) compared with patients with optimal adherence.

CONCLUSIONS

Nonadherence to ARVs was observed in 60%-80% of Medicaid patients, depending on the adherence measure used, and was associated with incremental HCRU and costs. Age, insurance type and coverage, previous ARV treatment, and HIV symptoms were predictors of adherence. Treatment options that enhance adherence and prevent developing virologic failure with drug resistance should be considered for HIV patients.

DISCLOSURES

This study was supported by Janssen Scientific Affairs, which was involved in the study design, data collection, data analysis, manuscript preparation, and publication decisions. Emond, Lafeuille, Romdhani, and Lefebvre are employees of Analysis Group, a consulting company that received research grants from Janssen Scientific Affairs to conduct this study. Dunn, Woodruff, Pesa, and Tandon are current employees and stockholders of Johnson & Johnson, owner of Janssen Scientific Affairs. Jiao was an employee of Janssen at the time of the study. Emond has received grants from Novartis, Regeneron, Aegerion, Lundbeck, Bristol-Myers Squibb, Bayer, Millennium, Allergan, AbbVie, and GlaxoSmithKline unrelated to this study. Part of the material in this study was presented at the Academy of Managed Care Pharmacy 2017 Annual Meeting; March 27-30, 2017; Denver, CO, and at the 9th International AIDS Society Conference; July 23-26, 2017; Paris, France.

Reporting on the prevalence of antiretroviral drug resistance in a regional HIV population over 20 years: a word of caution

BACKGROUND

Failure to achieve complete viral suppression with antiretroviral drugs (ARV) may lead to uncontrolled HIV replication, ARV resistance and negative outcomes. Monitoring and reporting of HIV resistance trends is important but problematic. We examined prevalent resistance rates in an HIV population over 20 years and document how rates may appear to vary greatly based solely on which parameters are utilized.

METHODS

We determined the annual use of genotypic antiretroviral resistance testing (GART) from 1995 to 2014 for all patients receiving HIV care in southern Alberta, Canada, and the presence of resistance mutations in those tested. The impact on prevalent resistance rates of using cumulative or latest GART was also determined.

RESULTS

Between 1995 and 2014, the number of patients with GART increased from <1% to 71%. Prevalent resistance in patients with GART decreased from a high of 52% in 2003 to 25.8% in 2014. However, if prevalence rates were reported using all active patients as denominator, including those without GART, prevalence increased from 0.7% to 18.5%. Prevalence rates were 7% to 9% higher in any given year if cumulative GART rather than latest GART results were used.

CONCLUSIONS

While prevalence resistance rates are decreasing, the precise rates being reported may vary due to increasing number of patients tested annually, using either the entire population as denominator or only patients with GART, and using either last or cumulative GART. Defining these parameters is critical if prevalence is to be compared over time or between HIV populations.

Maintaining the continuity of HIV-care records for patients transferring care between centers: challenges, workloads, needs and risks

With improved life expectancy, the medical records of HIV-infected patients are likely to be transferred repeatedly between HIV caregivers. The challenges, and risk for introducing medical error from incomplete record transfers are poorly understood. We measured number of requests for record transfer, the workload incurred, and explore, using genotypic antiretroviral resistance testing results (GART), the potential risk of incomplete records. Using retrospective database and chart review, we examined all patients followed at the Southern Alberta Clinic between 1 January 2004 and 1 January 2015, and determined how many patients transferred care into and out our program, the associated requests and the workload for record transfer. Using a complete record of all GART tests, the potential importance of absent historic records in current treatment decisions was analyzed. The annual churn rate was 22 ± 3.4%. We received requests for only 70% of patient records who had left our care. Median time for receipt of incoming medical records was 28 days; average clerical time for processing data was 2 hours/record. Of all GART results, 25% exhibited resistance. Of 111 patients with potentially misleading GART results (i.e., documented historical resistance not visible on more recent GART), 34 (30.6%) had moved in from elsewhere. Rigorous maintenance of the continuity of the HIV record is not universally practiced. Resources, costs and logistic challenges as well as a lack of appreciation of risks clearly shown by GART testing, may be relevant barriers. Addressing such issues is pressing as aging and transfers of care are increasingly common.

High Drop-off Along the HIV Care Continuum and ART Interruption Among Female Sex Workers in the Dominican Republic

BACKGROUND

Engagement in HIV care offers clear individual and societal benefits, but little evidence exists on the care experiences of key populations.

METHODS

A cross-sectional survey was conducted with 268 female sex workers (FSWs) living with HIV in Santo Domingo, Dominican Republic, to describe the HIV care continuum and to determine factors associated with antiretroviral therapy (ART) interruption.

RESULTS

FSWs disengaged throughout the care continuum with the highest drop-off after ART initiation. Most participants were linked to care (92%), retained in care (85%), and initiated onto ART (78%), but ART discontinuation and irregular adherence were frequent. Only 48% of participants had an undetectable HIV viral load. Overall, 36% of participants ever initiated onto ART reported lifetime experience with ART interruption. The odds of ART interruption were 3.24 times higher among women who experienced FSW-related discrimination [95% confidence interval (CI): 1.28 to 8.20], 2.41 times higher among women who used any drug (95% CI: 1.09 to 5.34), and 2.35 times higher among women who worked in an FSW establishment (95% CI: 1.20 to 4.60). Internalized stigma related to FSW was associated with higher odds of interruption (adjusted odds ratio: 1.09; 95% CI: 1.02 to 1.16), and positive perceptions of HIV providers were protective (adjusted odds ratio: 0.91; 95% CI: 0.85 to 0.98).

CONCLUSIONS

FSWs living with HIV confront multiple barriers throughout the HIV care continuum, many of which are related to the social context and stigmatization of sex work. Given the clear importance of maximizing the potential benefits of engagement in HIV care, there is an urgent need for interventions to support FSWs throughout the HIV care continuum.