Cost effectiveness of 'on demand' HIV pre-exposure prophylaxis for non-injection drug-using men who have sex with men in Canada

Costs and Cost-Effectiveness of Biomedical, Non-Surgical HIV Prevention Interventions: A Systematic Literature Review

BACKGROUND

Considerable evidence on the costs and cost-effectiveness of biomedical, non-surgical interventions to prevent human immunodeficiency virus (HIV) transmission has been generated over the last decade. This study aims to synthesize findings and identify remaining knowledge gaps to suggest future research priorities.

METHODS

A systematic literature review was carried out in August 2020 using the MEDLINE, Embase, Global Health and EconLit databases to retrieve economic evaluations and costing studies of oral pre-exposure prophylaxis (PrEP), injectable long-acting PrEP, vaginal microbicide rings and gels, HIV vaccines and broadly neutralizing antibodies. Studies reporting costs from the provider or societal perspective were included in the analysis. Those reporting on behavioural methods of prevention, condoms and surgical approaches (voluntary medical male circumcision) were excluded. The quality of reporting of the included studies was assessed using published checklists.

RESULTS

We identified 3007 citations, of which 87 studies were retained. Most were set in low- and middle-income countries (LMICs; n = 53) and focused on the costs and/or cost-effectiveness of oral PrEP regimens (n = 70). Model-based economic evaluations were the most frequent study design; only two trial-based cost-effectiveness analyses and nine costing studies were found. Less than half of the studies provided practical details on how the intervention would be delivered by the health system, and only three of these, all in LMICs, explicitly focused on service integration and its implication for delivery costs. 'Real-world' programme delivery mechanisms and costs of intervention delivery were rarely considered. PrEP technologies were generally found to be cost-effective only when targeting high-risk subpopulations. Single-dose HIV vaccines are expected to be cost-effective for all groups despite substantial uncertainty around pricing.

CONCLUSIONS

A lack of primary, detailed and updated cost data, including above-service level costs, from a variety of settings makes it difficult to evaluate the cost-effectiveness of specific delivery modes at scale, or to evaluate strategies for services integration. Closing this evidence gap around real-world implementation is vital, not least because the strategies targeting high-risk groups that are recommended by PrEP models may incur substantially higher costs and be of limited practical feasibility in some settings.

Out-of-pocket Expenses and Time Spent on Clinic Visits Among HIV Pre-exposure Prophylaxis Users and Other Clinic Attendees in Eswatini

User costs constitute a barrier to the uptake of HIV pre-exposure prophylaxis (PrEP), but their magnitude appears rarely assessed. In this prospective observational study, we assessed self-reported out-of-pocket expenses (OOPE) and time spent on clinic visits during a PrEP demonstration project in Eswatini. At six public primary care clinics, 240 PrEP users and other clinic attendees were interviewed after a clinic visit. Among the 79.2% of clinic attendees reporting any medical OOPE (e.g., expenses for consultations or drugs) and/or non-medical OOPE (e.g., expenses for transport, food, or phone use), the median total OOPE was $1.36 (IQR 0.91-1.96). Non-medical OOPE occurred mostly due to transport expenses. The median travel time for a clinic visit was 1.0 h (IQR 0.67-2.0). The median time spent in the clinic was 2.0 h (IQR 1.15-3.0). The median opportunity cost of a clinic visit was $7.54 (IQR 5.42-11) when valuing time spent on a clinic visit with Eswatini's per-capita gross domestic product. Our findings can guide measures to reduce the user costs of PrEP in Eswatini and other contexts in which oral PrEP is provided through health care facilities.

Cost-effectiveness analysis of the daily HIV pre-exposure prophylaxis in men who have sex with men in Barcelona

INTRODUCTION

Pre-Exposure Prophylaxis (PrEP) for HIV prevention has been implemented in several countries. Previous literature has shown that its cost-effectiveness (and, under some specifications, cost-saving character) is dependent on the reduction in price due to generics, the time-horizon and its effectiveness. The intervention has never been studied in Catalonia after the approval of the PrEP, a territory with extensive implementation.

METHODS

Economic evaluation of the implementation of HIV pre-exposition prophylaxis using administrative data from Men who have Sex with Men (MSM) who receive the treatment (at the generic price) compared with non-implementation. A deterministic compartmental model and a social perspective with a micro-costing approach over the time horizon 2022-2062 are used. A baseline 86% effectiveness of PrEP is assumed.

RESULTS

Daily oral PrEP is found to be cost-saving: discounted savings in costs are attained after 16 years, and after 40 years they reach 81 million euros. In terms of health indicators, 10,322 additional discounted QALYs are generated by the intervention. Results are sensitive to sexual behavioral patterns among MSM, the price of PrEP (reduced if offered on-demand), its effectiveness and the discount rate.

CONCLUSIONS

The use and promotion of PrEP in Catalonia is predicted to result in substantial health and monetary benefits because of reductions in HIV infections. Short-term investments in the promotion of PrEP will result in important cost-savings in the long term.

Are intersectoral costs considered in economic evaluations of interventions relating to sexually transmitted infections (STIs)? A systematic review

BACKGROUND/OBJECTIVE

Sexually transmitted infections (STIs) not only have an impact on the health sector but also the private resources of those affected, their families and other sectors of society (i.e. labour, education). This study aimed to i) review and identify economic evaluations of interventions relating to STIs, which aimed to include a societal perspective; ii) analyse the intersectoral costs (i.e. costs broader than healthcare) included; iii) categorise these costs by sector; and iv) assess the impact of intersectoral costs on the overall study results.

METHODS

Seven databases were searched: MEDLINE (PubMed), EMBASE (Ovid), Web of Science, CINAHL, PsycINFO, EconLit and NHS EED. Key search terms included terms for economic evaluation, STIs and specific infections. This review considered trial- and model-based economic evaluations conducted in an OECD member country. Studies were included that assessed intersectoral costs. Intersectoral costs were extracted and categorised by sector using Drummond's cost classification scheme (i.e. patient/family, productivity, costs in other sectors). A narrative synthesis was performed.

RESULTS

Twenty-nine studies qualified for data extraction and narrative synthesis. Twenty-eight studies applied a societal perspective of which 8 additionally adopted a healthcare or payer perspective, or both. One study used a modified payer perspective. The following sectors were identified: patient/family, informal care, paid labour (productivity), non-paid opportunity costs, education, and consumption. Patient/family costs were captured in 11 studies and included patient time, travel expenses, out-of-pocket costs and premature burial costs. Informal caregiver support (non-family) and unpaid help by family/friends was captured in three studies. Paid labour losses were assessed in all but three studies. Three studies also captured the costs and inability to perform non-paid work. Educational costs and future non-health consumption costs were each captured in one study. The inclusion of intersectoral costs resulted in more favourable cost estimates.

CONCLUSIONS

This systematic review suggests that economic evaluations of interventions relating to STIs that adopt a societal perspective tend to be limited in scope. There is an urgent need for economic evaluations to be more comprehensive in order to allow policy/decision-makers to make better-informed decisions.

Who is using PrEP on-demand? Factors associated with PrEP use modality among Black and Hispanic/Latino emerging adults

Pre-exposure prophylaxis (PrEP) is a highly efficacious HIV prevention medication, yet Black and Hispanic/Latino sexual minority men's and gender diverse individuals' (SMMGD) PrEP use is limited due to factors such as PrEP barriers and anticipated PrEP stigma. Although most individuals who use PrEP take it as a daily regimen, there is evidence that many SMMGD are interested in using "on-demand" (also known as event-driven or intermittent or 2-1-1) PrEP. We used stepwise multinomial logistic regression to explore factors associated with on-demand, daily, and no PrEP use among 820 Black and Hispanic/Latino SMMGD ages 18-29 in the United States. We found that greater reported PrEP barriers were associated with higher odds of using PrEP on-demand or not using PrEP compared to daily PrEP use. More past 3-month sex partners and greater comfort telling others about PrEP use were associated with lower odds of on-demand compared to daily PrEP use. In addition, compared to daily PrEP use, more past 3-month sex partners, greater comfort telling others about PrEP use, and higher anticipated PrEP stigma were associated with lower odds of no current PrEP use compared to daily PrEP use. Findings may inform clinical practices and interventions to promote PrEP uptake and adherence.

Clinical Considerations in the Selection of Preexposure Prophylaxis for HIV Prevention in Canada

According to the Public Health Agency of Canada, approximately 62,050 people were living with HIV in Canada in 2018, and of those, 13% were undiagnosed. Currently, no single strategy provides complete protection or is universally effective across all demographic groups at risk for HIV. However, HIV preexposure prophylaxis (PrEP) is the newest HIV prevention strategy that shows promise. To date, two products have received an indication for PrEP by Health Canada: emtricitabine/tenofovir disoproxil fumarate (Truvada®; FTC/TDF) and emtricitabine/tenofovir alafenamide (Descovy®; FTC/TAF). Despite the high efficacy of these PrEP intervention methods, access to PrEP in Canada remains low. Identifying and addressing barriers to PrEP access, especially in high-risk groups, are necessary to reduce HIV transmission in Canada. While guidelines published by the Center for Disease Control and Prevention (CDC) include FTC/TAF information, the efficacy of FTC/TAF for PrEP has not yet been considered in Canada's clinical practice guidelines. Thus, the current paper reviews data regarding the use of FTC/TDF and FTC/TAF for PrEP, which may be useful for Canadian healthcare providers when counseling and implementing HIV prevention methods. The authors highlight these data in relation to various at-risk populations and review ongoing clinical trials investigating novel PrEP agents. Overall, FTC/TDF PrEP is effective for many populations, including men who have sex with men, transgender women, heterosexuals with partners living with HIV, and people who use drugs. While there is fewer data reported on the efficacy of FTC/TAF to date, recent clinical trials have demonstrated noninferiority of FTC/TAF in comparison to FTC/TDF. Notably, as studies have shown that FTC/TAF maintains renal function and bone mineral density to a greater extent than FTC/TDF, FTC/TAF may be a safer option for patients experiencing renal and/or bone dysfunction, for those at risk of renal and bone complications, and for those who develop FTC/TDF-related adverse events.

The Cost-Effectiveness of HIV/STI Prevention in High-Income Countries with Concentrated Epidemic Settings: A Scoping Review

The purpose of this scoping review is to establish the state of the art on economic evaluations in the field of HIV/STI prevention in high-income countries with concentrated epidemic settings and to assess what we know about the cost-effectiveness of different measures. We reviewed economic evaluations of HIV/STI prevention measures published in the Web of Science and Cost-Effectiveness Registry databases. We included a total of 157 studies focusing on structural, behavioural, and biomedical interventions, covering a variety of contexts, target populations and approaches. The majority of studies are based on mathematical modelling and demonstrate that the preventive measures under scrutiny are cost-effective. Interventions targeted at high-risk populations yield the most favourable results. The generalisability and transferability of the study results are limited due to the heterogeneity of the populations, settings and methods involved. Furthermore, the results depend heavily on modelling assumptions. Since evidence is unequally distributed, we discuss implications for future research.

Pre-exposure prophylaxis and its implications in Mexico: notions of men who have sex with men

Background The aim of this study was to analyse ideas regarding pre-exposure prophylaxis (PrEP) for the prevention of HIV among groups of men who have sex with men in Mexico for future implementation in health services.

METHODS

During 2015, 54 people participated in four focus groups in three Mexican cities. Issues related to challenges for uses and limitations of PrEP were explored.

RESULTS

In contrast with other qualitative studies, which emphasised problems with relationships with other people for PrEP use or access to key populations, Mexican participants focused their concerns around the public health services organisation: PrEP is too expensive and the health services have no resources, which will affect services and result in discrimination. Participants identified possible stigmatisation related to prejudices of medical providers who do not approve the decreased use of condoms. As a potential solution, participants suggested that the Mexican Government could negotiate a lower cost for PrEP and public health services could provide the medication, with periodical review of the arrangements by civil organisations.

CONCLUSION

In the current context of the new Mexican government, it is necessary to propose public politics focused on negotiating with pharmaceutical companies on the costs of the PrEP, coordinating public services with groups within civil society and strengthening policies and actions to reduce stigma and discrimination.

Offering a choice of daily and event-driven preexposure prophylaxis for men who have sex with men in the Netherlands: a cost-effectiveness analysis

OBJECTIVES

To assess the cost-effectiveness of a preexposure prophylaxis (PrEP) programme offering a choice of daily and event-driven PrEP for men who have sex with men (MSM) in the Netherlands.

METHODS

We used an agent-based transmission model and an economic model to simulate a programme offering only daily PrEP and a programme offering daily and event-driven PrEP. Use of PrEP medication and preference for daily versus event-driven PrEP were estimated from the Amsterdam PrEP Demonstration Project (AMPrEP). We calculated costs, quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios (ICER), over 2018-2027. An ICER less than €20 000 per QALY gained was considered cost-effective.

RESULTS

Using AMPrEP data, we estimated that 27% of PrEP users chose event-driven PrEP with a median of 12 pills per month; daily PrEP users used a median of 30 pills per month. With PrEP, 3740 HIV infections were averted and 1482 QALYs were gained over 2018-2027, compared to the scenario without PrEP. The probability of the PrEP programme being cost-effective (compared to not having a PrEP programme) increased from 91% with daily PrEP to 94% with a choice of daily and event-driven PrEP. The probability of being cost-saving increased from 42% with only daily PrEP to 48% with choice of daily and event-driven PrEP.

CONCLUSIONS

A daily PrEP programme for MSM would be cost-effective. Providing a choice of daily and event-driven PrEP can result in savings and is more likely to be cost-effective and cost-saving, compared to a programme offering only daily PrEP.

Choosing event-driven and daily HIV pre-exposure prophylaxis - data from two European PrEP demonstration projects among men who have sex with men

INTRODUCTION

Daily and event-driven PrEP are both efficacious in reducing the risk for HIV infection. However, the practice of event-driven PrEP (edPrEP) is less well studied, in particular when provided as an alternative to daily PrEP. We studied regimen preferences and switches, and sexually transmitted infection (STI) incidence.

METHODS

We analysed pooled data from two prospective cohort studies among MSM: Be-PrEP-ared, Belgium and AMPrEP, the Netherlands. In both projects, participants could choose between daily and edPrEP at three-monthly study visits, when they were also screened for sexually transmitted infections including hepatitis C (HCV). We assessed the proportion choosing each regimen, and the determinants of choosing edPrEP at baseline. Additionally, we compared the incidence rates (IRs) of HCV, syphilis and chlamydia or gonorrhoea between regimens using Poisson regression. The study period was from 3 August 2015 until 24 September 2018.

RESULTS AND DISCUSSION

We included 571 MSM, of whom 148 (25.9%) chose edPrEP at baseline. 31.7% of participants switched regimen at least once. After 28 months, 23.5% used edPrEP. Older participants (adjusted odds ratio (aOR) = 1.38 per 10 years, 95% confidence interval (CI) = 1.15 to 1.64) and those unemployed (aOR = 1.68, 95% CI = 1.03 to 1.75) were more likely to initially choose edPrEP. IR of HCV and syphilis did not differ between regimens, but the IR of chlamydia/gonorrhoea was higher among daily users (adjusted incidence rate ratio = 1.61, 95% CI = 1.35 to 1.94).

CONCLUSIONS

A quarter of participants chose edPrEP at baseline and at 28 months this proportion was similar. Although the IR of HCV and syphilis were similar in the two regimens, the lower incidence of chlamydia and gonorrhoea among edPrEP users may suggest that less frequent STI testing of this group could be considered.

Adherence to event-driven HIV PrEP among men who have sex with men in Amsterdam, the Netherlands: analysis based on online diary data, 3-monthly questionnaires and intracellular TFV-DP

INTRODUCTION

Event-driven pre-exposure prophylaxis (edPrEP) with oral tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) is highly effective for preventing HIV acquisition in men who have sex with men (MSM) and is preferred over daily PrEP by some MSM. However, it is largely unknown how well MSM adhere to edPrEP. We then aimed to assess PrEP protection during CAS among MSM using edPrEP and participating in the Amsterdam PrEP demonstration project (AMPrEP).

METHODS

We analysed data from participants enrolled in AMPrEP who were taking edPrEP. We measured adherence through (1) a mobile application in which sexual behaviour and PrEP-use were recorded daily, (2) three-monthly self-completed questionnaires and (3) dried blood spot (DBS) samples collected around six, twelve and twenty-four months after PrEP initiation. We assessed the proportion of days with condomless anal sex (CAS) acts that were protected by PrEP, per partner type (i.e. steady partners, known casual partners, unknown casual partners), and the proportion of three-month periods during which PrEP was correctly used. Intracellular TFV-diphosphate (TFV-DP) concentrations were determined from DBS. Good adherence was defined as at least one tablet before and one tablet within 48 hours after a CAS act.

RESULTS

Between 11 September 2015 and 6 October 2019, 182 of 376 MSM (48.4%) used edPrEP for at least one three-month period. Of the 8224 CAS days that were reported in the app during edPrEP-use, we observed good protection for most CAS days involving steady partners (n = 1625/2455, 66.9%), known casual partners (n = 3216/3472, 92.6%) and unknown casual partners (n = 2074/2297, 90.3%). Men reported consistently correct PrEP-use in 851 (81.4%) of the 1046 three-month periods of edPrEP-use. The median TFV-DP concentration was 591 fmol/sample (interquartile range = 270 to 896).

CONCLUSIONS

Adherence to edPrEP was high as determined from the online app and questionnaire. DBS measurements were consistent with two to three tablets per week on average.

Perspectives on and preferences for on-demand and long-acting PrEP among sexual and gender minority adolescents assigned male at birth

INTRODUCTION

Sexual and gender minority (SGM) adolescents assigned male at birth who have sex with male partners are at increased risk for HIV. Daily oral pre-exposure prophylaxis (PrEP) is available for minor adolescents in the United States, who may have difficulty with adherence. Adolescents' perspectives toward emerging PrEP delivery methods that would not require daily pill-taking have not been well-explored.

METHODS

We conducted online surveys and focus groups in November 2018-February 2019 with 59 SGM adolescents assigned male at birth who reported sex with or attraction to male partners. Questions assessed their perspectives on and preferences for biomedical (on-demand, injection, implant) and non-biomedical HIV prevention options (condoms). Data were analyzed thematically.

RESULTS

Of all prevention options, the implant and condoms were rated highest, and participants preferred the implant over other biomedical options. Convenience, duration, and ease of access played important roles in adolescents' preferences. Parents were viewed as a barrier to taking PrEP regardless of delivery method due to their role in adolescents' ability to access healthcare.

CONCLUSIONS

SGM adolescents are interested in long-acting PrEP, yet also perceive substantial obstacles to using biomedical prevention that reflect adolescents' developmental contexts.

POLICY IMPLICATIONS

State laws expanding adolescents' access to HIV preventive services, sex education inclusive of PrEP information, and parent- and provider-initiated PrEP conversations can reduce barriers regardless of PrEP delivery method. Research to accelerate the availability of long-acting implants for adolescents is needed.

Cost-effectiveness of the long-acting regimen cabotegravir plus rilpivirine for the treatment of HIV-1 and its potential impact on adherence and viral transmission: A modelling study

Introduction

Combination antiretroviral therapy (cART) improves outcomes for people living with HIV (PLWH) but requires adherence to daily dosing. Suboptimal adherence results in reduced treatment effectiveness, increased costs, and greater risk of resistance and onwards transmission. Treatment with long-acting (LA), injection-based ART administered by healthcare professionals (directly observed therapy (DOT)) eliminates the need for adherence to daily dosing and may improve clinical outcomes. This study reports the cost-effectiveness of the cabotegravir plus rilpivirine LA regimen (CAB+RPV LA) and models the potential impact of LA DOT therapies.

Methods

Parameterisation was performed using pooled data from recent CAB+RPV LA Phase III trials. The analysis was conducted using a cohort-level hybrid decision-tree and state-transition model, with states defined by viral load and CD4 cell count. The efficacy of oral cART was adjusted to reflect adherence to daily regimens from published data. A Canadian health service perspective was adopted.

Results

CAB+RPV LA is predicted to be the dominant intervention when compared to oral cART, generating, per 1,000 patients treated, lifetime cost-savings of $1.5 million, QALY and life-year gains of 107 and 138 respectively with three new HIV cases averted.

Conclusions

Economic evaluations of LA DOTs need to account for the impact of adherence and HIV transmission. This study adds to the existing literature by incorporating transmission and using clinical data from the first LA DOT regimen. Providing PLWH and healthcare providers with novel modes of ART administration, enhancing individualisation of treatment, may facilitate the achievement of UNAIDS 95-95-95 objectives.

Cost utility analysis of HIV pre exposure prophylaxis among men who have sex with men in Israel

Background

Between 2011 and 2015, Men who have sex with men (MSM) accounted for nearly half of new HIV cases among men in Israel. This study carries out a cost-utility analysis of PrEP (HIV Pre Exposure Prophylaxis), an antiretroviral medication that can protect against the acquisition of HIV infection, whose incidence rate in Israel is around 1.74 per 1000 MSM.

Method

Epidemiological, demographic, health service utilisation and economic data were integrated into a spread-sheet model in order to calculate the cost per averted disability-adjusted life year (DALY) of the intervention from a societal perspective, in mid-2018 US$ using a 3% discount rate. Cost utility analyses were performed for both types of PrEP delivery (continuous regimen and on-demand), together with sensitivity analyses on numbers of condom users who take up PrEP (baseline 25%) and subsequently abandon condom use (baseline 75%), PrEP efficacy (baseline 86%), PrEP prices and monitoring costs.

Results

Around 21.3% of MSM are high risk (as defined by having unprotected anal intercourse). Offering PrEP to this group would have a ten year net cost of around 1563 million USD, preventing 493 persons from becoming HIV-positive, averting around 1616 DALYs at a cost per averted DALY of around 967,744 USD. This will render the intervention to be not cost-effective. PrEP drug prices would have to fall dramatically (by 90.7%) for the intervention to become cost-effective (i.e. having a cost per averted DALY less than thrice GNP per capita) in Israel. PrEP remains not cost-effective (at 475,673 USD per averted DALY) even if intervention costs were reduced by using an “on demand” instead of a daily schedule. Even if there were no changes in condom use, the resultant 411,694 USD cost-utility ratio is still not cost-effective.

Conclusions

Despite PrEPs high effectiveness against HIV, PrEP was found not to be cost-effective in the Israeli context because of a combination of relatively low HIV incidence, high PrEP costs, with a likelyhood that some low-risk MSM (ie: who use condoms) may well begin taking PrEP and as a consequence many of these will abandon condom use. Therefore, ways of minimizing these last two phenomena need to be found.

Study on Pre-Exposure Prophylaxis Regimens among Men Who Have Sex with Men: A Prospective Cohort Study

Background: There are limited studies on the medication regimen of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in China. This study compared the effectiveness of and adherence to two prophylactic HIV medication regimens, which provided evidence and guidance for the application and promotion of the PrEP strategy in the MSM population in China. Methods: We conducted an open, non-randomized, multicenter, parallel, controlled clinical intervention study in western China. Subjects were recruited by convenience sampling at research centers in Chongqing, Guangxi, Xinjiang and Sichuan, China from April 2013 to March 2015, and they were categorized into the daily PrEP, event-driven and blank control groups. Tenofovir disoproxil fumarate (TDF; 300 mg/dose) was administered to subjects in the daily PrEP and event-driven groups, and all subjects were followed up every 12 weeks for 96 weeks. Demographic, behavioral, psychological characteristics and AIDS-related attitudes were assessed using self-completed questionnaires. TDF serum concentrations in subjects in Chongqing and Sichuan were quantified after systematic sampling. Results: Of the 2422 enrolled MSM, 856 were eligible for statistical analysis (PrEP group: 385 and event-driven group: 471); 30 and 32 subjects in daily PrEP and event-driven groups, respectively, were HIV-positive; the incidence of HIV infection was as follows: daily PrEP group, 6.60 cases/100 person-years and event-driven group, 5.57 cases/100 person-years (relative risk (RR) 95% confidence interval (CI) was 0.844 (0.492-1.449)); HIV incidence did not differ significantly when stratified by medication adherence or sites. When the medication adherence rate was ≥80%, the median TDF serum concentrations were 0.458 mg/L, and 0.429 mg/L in the daily PrEP, and event-driven groups, respectively (not significant; p > 0.05); Subjects who were in the event-driven PrEP group (OR = 2.152, 95% CI: 1.566-2.957), had fewer male sexual partners in the last two weeks (OR = 0.685, 95% CI: 0.563-0.834), were one year older on average (OR = 1.022, 95% CI: 1.002-1.043), considered that medication kept them safe, were less worried about others knowing they took medicine and were more likely to have high adherence. Conclusions: The efficacies of daily TDF and event-driven TDF use were not significantly different in preventing new infections among HIV-negative MSM. Event-driven TDF use is economical and effective and is worth popularizing. Our results provide evidence for the application and promotion of the PrEP strategy in the MSM population in China.

Motives for choosing, switching and stopping daily or event-driven pre-exposure prophylaxis - a qualitative analysis

INTRODUCTION

In settings where both daily and event-driven pre-exposure prophylaxis (PrEP) are offered to men who have sex with men (MSM), a clear understanding of the motives to choose between the different dosing-regimens can facilitate more effective PrEP implementation. We therefore studied the motives for choosing for, switching between, and stopping daily or event-driven PrEP.

METHODS

We used data (August 2015-June 2017) from the prospective, longitudinal, open-label Amsterdam PrEP demonstration study, in which daily (dPrEP) and event-driven PrEP (edPrEP) were offered to 374 HIV-negative MSM and two transgender persons. Participants self-selected the preferred PrEP-regimen at baseline and could switch regimens at three-monthly follow-up visits. We measured motives for choosing PrEP-regimen at baseline and for switching and stopping PrEP at follow-up visits. Open- and closed-end items were combined and qualitatively analysed.

RESULTS

Choices of PrEP-regimens were determined by personal and contextual factors, involving the perceived self-efficacy concerning adherence, the risk-context, and the anticipated impact of PrEP on physical and sexual wellbeing. dPrEP was preferred because of the anticipated better adherence and the fear of side-effects relating to edPrEP re-initiations. Moreover, dPrEP was perceived to be more effective than edPrEP. Motives to choose edPrEP were the expected physical burden of dPrEP, anticipated side-effects of dPrEP, and fear to forget daily doses. Regarding the risk-context: dPrEP was preferred for unplanned and/or frequent sex, while edPrEP was chosen when risk was predictable and/or less frequent. While some chose for dPrEP to gain more sexual freedom, others chose for edPrEP to minimize sexual risk episodes. Changes in the above factors, such as changing risk patterns, changing relationships or changing physical conditions, resulted in switching regimens. Choices to stop PrEP were related to lower sexual risk, adherence issues and side-effects.

CONCLUSIONS

The great diversity of motives illustrates the importance of offering a choice of PrEP-regimens. In counselling of MSM starting PrEP, choices for PrEP-regimens may be addressed as a continuum of flexible and changeable options over time. This may help individuals choose the PrEP-regimen that best fits their current sexual context, priorities and personal capabilities and therefore will be more easily adhered to.

Taiwan guideline on oral pre-exposure prophylaxis for HIV prevention - 2018 update

Pre-exposure prophylaxis (PrEP) for prevention of human immunodeficiency virus infection is proved to be effective and has been implemented worldwide. This article introduces the guideline development and revised recommendations and guidance on PrEP provision in the updated Taiwan PrEP guideline. The Taiwan PrEP guideline writing group searched randomized controlled trials and guidelines published before October 2017 through Medline/PubMed, Cochrane Database, Embase and ClinicalTrials.gov database. Keywords included pre(-)exposure prophylaxis, PrEP, Truvada, tenofovir, HIV, and AIDS. Each selected article was assessed by two authors using the Grading of Recommendations Assessment, Development and Evaluation. External reviewers were invited to independently evaluate the revised manuscript per the Appraisal of Guidelines for Research and Evaluation II. Before publication, a public consultation was held to reach consensus on the updated guideline among providers, civil society, and Taiwan Centers for Disease Control. Four systematic reviews and 28 original articles were reviewed by Taiwan PrEP writing group. The second version of the Taiwan PrEP guideline was released in March 2018. We recommended daily PrEP use for the following populations: strong recommendation and high quality of evidence for men who have sex with men (MSM) and transgender women (TGW), as well as heterosexual serodiscordant couples; weak recommendation and high quality of evidence for people who inject drugs, while weak recommendation and moderate quality of evidence for at-risk heterosexual men and women. There is high-quality evidence for event-driven PrEP in MSM and likely TGW, and we additionally recognized these key populations could benefit from such dosing regimen.

[The role of biomedical interventions in HIV prevention: Pre-exposure Prophylaxis (PrEP)]

HIV infection remains an important public health problem worldwide. The traditional preventive measures, such as sexual education, screening, and early antiretroviral treatment initiation, despite having shown their effectiveness, are not enough to control new infections. In this context, Pre-Exposure Prophylaxis (PrEP) has been investigated as a preventive measure. Currently, it has been extensively documented that the administration of antiretroviral treatment in an HIV exposed, but not infected population, could reduce the risk of transmission without significant drawbacks. Despite its high efficacy for HIV prevention, the use of PrEP remains a controversial measure, particularly its cost-effectiveness. For this reason, the access to PrEP is not available for all the HIV risk groups. Therefore, and based on the evidence found, the current approach must be the repercussions of not to implement PrEP, more than its cost or its effectiveness.

Competing biomedical HIV prevention strategies: potential cost-effectiveness of HIV vaccines and PrEP in Seattle, WA

INTRODUCTION

Promising HIV vaccine candidates are steadily progressing through the clinical trial pipeline. Once available, HIV vaccines will be an important complement but also potential competitor to other biomedical prevention tools such as pre-exposure prophylaxis (PrEP). Accordingly, the value of HIV vaccines and the policies for rollout may depend on that interplay and tradeoffs with utilization of existing products. In this economic modelling analysis, we estimate the cost-effectiveness of HIV vaccines considering their potential interaction with PrEP and condom use.

METHODS

We developed a dynamic model of HIV transmission among the men who have sex with men population (MSM), aged 15-64 years, in Seattle, WA offered PrEP and HIV vaccine over a time horizon of 2025-2045. A healthcare sector perspective with annual discount rate of 3% for costs (2017 USD) and quality-adjusted life years (QALYs) was used. The primary economic endpoint is the incremental cost-effectiveness ratio (ICER) when compared to no HIV vaccine availability.

RESULTS

HIV vaccines improved population health and increased healthcare costs. Vaccination campaigns achieving 90% coverage of high-risk men and 60% coverage of other men within five years of introduction are projected to avoid 40% of new HIV infections between 2025 and 2045. This increased total healthcare costs by $30 million, with some PrEP costs shifted to HIV vaccine spending. HIV vaccines are estimated to have an ICER of $42,473/QALY, considered cost-effective using a threshold of $150,000/QALY. Results were most sensitive to HIV vaccine efficacy and future changes in the cost of PrEP drugs. Sensitivity analysis found ranges of 30-70% HIV vaccine efficacy remained cost-effective. Results were also sensitive to reductions in condom use among PrEP and vaccine users.

CONCLUSIONS

Access to an HIV vaccine is desirable as it could increase the overall effectiveness of combination HIV prevention efforts and improve population health. Planning for the rollout and scale-up of HIV vaccines should carefully consider the design of policies that guide interactions between vaccine and PrEP utilization and potential competition.

Men who have sex with men more often chose daily than event-driven use of pre-exposure prophylaxis: baseline analysis of a demonstration study in Amsterdam

INTRODUCTION

The Amsterdam PrEP project is a prospective, open-label demonstration study at a large sexually transmitted infection (STI) clinic. We examined the uptake of PrEP; the baseline characteristics of men who have sex with men (MSM) and transgender persons initiating PrEP; their choices of daily versus event-driven PrEP and the determinants of these choices.

METHODS

From August 2015 through May 2016, enrolment took place at the STI clinic of the Public Health Service of Amsterdam, the Netherlands. MSM or transgender persons were eligible if they had at least one risk factor for HIV infection within the preceding six months. Participants were offered a choice between daily or event-driven use of tenofovir/emtricitabine. Baseline data were analysed using descriptive statistics and multivariable analysis was employed to determine variables associated with daily versus event-driven PrEP.

RESULTS

Online applications were submitted by 870 persons, of whom 587 were invited for a screening visit. Of them, 415 were screened for eligibility and 376 initiated PrEP. One quarter (103/376, 27%) chose event-driven PrEP. Prevalence of bacterial STI was 19.0% and mean condomless anal sex (CAS) episodes in the preceding three months were 11. In multivariable analysis, older age (≥45 vs. ≤34, aOR 2.1, 95% CI 1.2 to 3.9), being involved in a steady relationship (aOR 1.7, 95% CI 1.0 to 2.7), no other daily medication use (aOR 0.6, 95% CI 0.3 to 0.9), and fewer episodes of CAS (per log increase aOR 0.7, 95% CI 0.6 to 0.9) were determinants for choosing event-driven PrEP.

DISCUSSION

PrEP programmes are becoming one of the more important intervention strategies with the goal of reducing incident HIV-infection and we were unable to accommodate many of the persons applying for this study. Offering a choice of dosing regimen to PrEP users may enable further personalization of HIV prevention strategies and enhance up-take, adherence and cost-effectiveness.

CONCLUSIONS

The majority of participants preferred daily versus event-driven use. Within this majority, a high number of CAS episodes before PrEP initiation was reported and we observed a high prevalence of STI. Determinants of choosing event-driven PrEP were older age, fewer CAS episodes, no other daily medication use, and involved in a steady relationship.

Antiretroviral agents in pre-exposure prophylaxis: emerging and advanced trends in HIV prevention

OBJECTIVES

Antiretroviral agents (ARVs) have been the most promising line of therapy in the management of human immunodeficiency virus (HIV) infections. Some of these ARVs are used in the pre-exposure prophylaxis (PrEP) to suppress the transmission of HIV. Prophylaxis is primarily used in uninfected people, before exposure, to effectively prevent HIV infection. Several studies have shown that ART PrEP prevents HIV acquisition from sexual, blood and mother-to-child transmissions. However, there are also several challenges and limitations to PrEP. This review focuses on the current antiretroviral therapies used in PrEP.

KEY FINDINGS

Among ARVs, the most common drugs employed from the class of entry inhibitors are maraviroc (MVC), which is a CCR5 receptor antagonist. Other entry inhibitors like emtricitabine (FTC) and tenofovir (TFV) are also used. Rilpivirine (RPV) and dapivirine (DPV) are the most common drugs employed from the Non-nucleoside reverse transcriptase inhibitor (NNRTIs) class, whereas, tenofovir disoproxil fumarate (TDF) is primarily used in the Nucleoside Reverse Transcriptase Inhibitor (NRTIs) class. Cabotegravir (CAB) is an analog of dolutegravir, and it is an integrase inhibitor. Some of these drugs are also used in combination with other drugs from the same class.

SUMMARY

Some of the most common pre-exposure prophylactic strategies employed currently are the use of inhibitors, namely entry inhibitors, non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, integrase and protease inhibitors. In addition, we have also discussed on the adverse effects caused by ART in PrEP, pharmacoeconomics factors and the use of antiretroviral prophylaxis in serodiscordant couples.

Genetic Strategies for HIV Treatment and Prevention

Conventional HIV gene therapy approaches are based on engineering HIV target cells that are non-permissive to viral replication. However, expansion of gene-modified HIV target cells has been limited in patients. Alternative genetic strategies focus on generating gene-modified producer cells that secrete antiviral proteins (AVPs). The secreted AVPs interfere with HIV entry, and, therefore, they extend the protection against infection to unmodified HIV target cells. Since any cell type can potentially secrete AVPs, hematopoietic and non-hematopoietic cell lineages can function as producer cells. Secretion of AVPs from non-hematopoietic cells opens the possibility of using a genetic approach for HIV prevention. Another strategy aims at modifying cytotoxic T cells to selectively target and eliminate infected cells. This review provides an overview of the different genetic approaches for HIV treatment and prevention.

In what circumstances could nondaily preexposure prophylaxis for HIV substantially reduce program costs?

Supplemental Digital Content is available in the text

Objectives:

To review the main factors influencing the costs of nondaily oral preexposure prophylaxis (PrEP) with tenofovir (±emtricitabine). To estimate the cost reductions possible with nondaily PrEP compared with daily PrEP for different populations (MSM and heterosexual populations).

Design:

Systematic review and data triangulation.

Methods:

We estimated the required number of tablets/person/week for dosing regimens used in the HPTN 067/ADAPT (daily/time-driven/event-driven) and IPERGAY (on-demand) trials for different patterns of sexual intercourse. Using trial data, and behavioural and cost data obtained through systematic literature reviews, we estimated cost savings resulting from tablet reductions for nondaily versus daily oral PrEP, assuming 100% adherence.

Results:

Among different populations being prioritized for PrEP, the median reported number of days of sexual activity varied between 0 and 2 days/week (0–1.5 days/week for MSM, 1–2 days/week for heterosexual populations). With 100% adherence and two or fewer sex-days/week, HPTN 067/ADAPT nondaily regimens reduced the number of tablets/week by more than 40% compared with daily PrEP. PrEP program costs were reduced the most in settings with high drug costs, for example, by 66–69% with event-driven PrEP for French/US populations reporting on average one sex-day/week.

Conclusion:

Nondaily oral PrEP could lower costs substantially (>50%) compared with daily PrEP, particularly in high-income countries. Adherence and efficacy data are needed to determine cost-effectiveness.

Costs and benefits of on-demand HIV preexposure prophylaxis in MSM

OBJECTIVES

We undertook the economic evaluation of the double-blind randomized ANRS-IPERGAY trial, which showed the efficacy of on-demand preexposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF)-emtricitabine (FTC) in preventing HIV infection among high-risk MSM.

DESIGN AND METHODS

The economic evaluation was prospective. Counseling, drugs (TDF-FTC at &OV0556;500.88 for 30 tablets), tests, visits, and hospital admissions were valued based on in-trial use. The cost of on-demand PrEP/HIV infection averted was compared with the yearly and lifetime costs of HIV infection in France in a cost and benefits analysis.

RESULTS

The yearly number of participants needed to treat to prevent one HIV infection was 17.6 (95% confidence interval = 10.7-49.9). The annual cost of counseling was &OV0556;690/participant. The total 1-year costs of PrEP were &OV0556;4271/participant, of which &OV0556;3129 (73%) were drug costs corresponding to 15 tablets of TDF-FTC/month. The yearly cost of on-demand PrEP to avoid one infection was &OV0556;75 258. Using TDF-FTC generic (&OV0556;179.9/30 tablets) reduced the 1-year costs of on-demand PrEP to &OV0556;2271/participant and &OV0556;39 970/infection averted, respectively. Using TDF-FTC at international market discounted prices (&OV0556;60/30 tablets) reduced the costs to &OV0556;1517/participant and the cost to &OV0556;26 787/infection averted, comparable with the yearly treatment cost of HIV infection in France. On-demand PrEP was found to be cost saving in France if the duration of exposure was less than 7.5 years at current drug price and 13 years at generic price.

CONCLUSION

On-demand PrEP in high-risk MSM with TDF-FTC can be considered cost saving. Other benefits include the treatments of other diseases and reductions in secondary infections.

Can we afford to offer pre-exposure prophylaxis to MSM in Catalonia? Cost-effectiveness analysis and budget impact assessment

Pre-exposure prophylaxis (PrEP) effectiveness has been well established. This study aims to assess the cost-effectiveness of providing PrEP, estimate the number of eligible MSM, and its budget impact in Catalonia. Cost-effectiveness analysis compared costs of on daily basis and "on demand" PrEP to prevent one infection with lifetime costs of one HIV infection. We estimated the total cost of providing PrEP by estimating number of eligible MSM, and included in the budget impact assessment antiretroviral and laboratory costs. Costs were lower for the on-demand PrEP group by €64015.1 and the incremental benefit was nearly 15 life-years and 17 quality-adjusted life-years gained. The incremental cost-effectiveness ratio (ICER) was cost-effective at €6281.62 when undiscounted PrEP was given daily. On-demand PrEP can be considered cost-saving in 20 years if the price is reduced by 90%. The number of eligible MSM in Catalonia ranges from 5,989 to 10,972. At current antiretroviral costs, the annual cost would range between €25.3-46.7 million/year (on demand PrEP), and €42.9-78.7 million/year (daily basis PrEP). PrEP is most cost-effective if targeted towards groups with high incidence rates of over 3%/year. Beneficial ICER depends on reducing the current price of Truvada® and ensuring that effectiveness is maintained at high levels.

Recent advances in pre-exposure prophylaxis for HIV

Although pre-exposure prophylaxis (PrEP)-the use of antiretroviral drugs by non-infected people to prevent the acquisition of HIV-is a promising preventive option, important public health questions remain. Daily oral emtricitabine (FTC)-tenofovir disoproxil fumarate (TDF) is highly efficacious in preventing the acquisition of HIV in people at risk as a result of a range of different types of sexual exposure. There is good evidence of efficacy in women and men, and when men who have sex with men use event based dosing. Studies have been conducted in several countries and epidemics. Because adherence to this treatment varies greatly there are questions about its public health benefit. Oral FTC-TDF is extremely safe, with minimal impact on kidney, bone, or pregnancy outcomes, and there is no evidence that its effectiveness has been reduced by risk compensation during open label and programmatic follow-up. It is too early to assess the impact of this treatment on the incidence of sexually transmitted infections (STIs) at a population level. Many challenges remain. Access to pre-exposure prophylaxis is limited and disparities exist, including those governed by race and sex. Different pricing and access models need to be explored to avoid further widening inequalities. The optimal combination prevention program needs to be defined, and this will depend on local epidemiology, service provision, and cost effectiveness. This review updates the evidence base for pre-exposure prophylaxis regarding its effectiveness, safety, and risk compensation.

Cost-effectiveness of pre-exposure prophylaxis for HIV prevention in men who have sex with men in the UK: a modelling study and health economic evaluation

BACKGROUND

In the UK, HIV incidence among men who have sex with men (MSM) has remained high for several years, despite widespread use of antiretroviral therapy and high rates of virological suppression. Pre-exposure prophylaxis (PrEP) has been shown to be highly effective in preventing further infections in MSM, but its cost-effectiveness is uncertain.

METHODS

In this modelling study and economic evaluation, we calibrated a dynamic, individual-based stochastic model, the HIV Synthesis Model, to multiple data sources (surveillance data provided by Public Health England and data from a large, nationally representative survey, Natsal-3) on HIV among MSM in the UK. We did a probabilistic sensitivity analysis (sampling 22 key parameters) along with a range of univariate sensitivity analyses to evaluate the introduction of a PrEP programme with sexual event-based use of emtricitabine and tenofovir for MSM who had condomless anal sexual intercourse in the previous 3 months, a negative HIV test at baseline, and a negative HIV test in the preceding year. The main model outcomes were the number of HIV infections, quality-adjusted life-years (QALYs), and costs.

FINDINGS

Introduction of such a PrEP programme, with around 4000 MSM initiated on PrEP by the end of the first year and almost 40 000 by the end of the 15th year, would result in a total cost saving (£1·0 billion discounted), avert 25% of HIV infections (42% of which would be directly because of PrEP), and lead to a gain of 40 000 discounted QALYs over an 80-year time horizon. This result was particularly sensitive to the time horizon chosen, the cost of antiretroviral drugs (for treatment and PrEP), and the underlying trend in condomless sex.

INTERPRETATION

This analysis suggests that the introduction of a PrEP programme for MSM in the UK is cost-effective and possibly cost-saving in the long term. A reduction in the cost of antiretroviral drugs (including the drugs used for PrEP) would substantially shorten the time for cost savings to be realised.

FUNDING

National Institute for Health Research.

Economic evaluation of HIV pre-exposure prophylaxis among men-who-have-sex-with-men in England in 2016

Clinical effectiveness of pre-exposure prophylaxis (PrEP) for preventing HIV acquisition in men who have sex with men (MSM) at high HIV risk is established. A static decision analytical model was constructed to inform policy prioritisation in England around cost-effectiveness and budgetary impact of a PrEP programme covering 5,000 MSM during an initial high-risk period. National genitourinary medicine clinic surveillance data informed key HIV risk assumptions. Pragmatic large-scale implementation scenarios were explored. At 86% effectiveness, PrEP given to 5,000 MSM at 3.3 per 100 person-years annual HIV incidence, assuming risk compensation (20% HIV incidence increase), averted 118 HIV infections over remaining lifetimes and was cost saving. Lower effectiveness (64%) gave an incremental cost-effectiveness ratio of + GBP 23,500 (EUR 32,000) per quality-adjusted life year (QALY) gained. Investment of GBP 26.9 million (EUR 36.6 million) in year-1 breaks even anywhere from year-23 (86% effectiveness) to year-33 (64% effectiveness). PrEP cost-effectiveness was highly sensitive to year-1 HIV incidence, PrEP adherence/effectiveness, and antiretroviral drug costs. There is much uncertainty around HIV incidence in those given PrEP and adherence/effectiveness, especially under programme scale-up. Substantially reduced PrEP drug costs are needed to give the necessary assurance of cost-effectiveness, and for an affordable public health programme of sufficient size.

Cost-effectiveness of screening for HIV in primary care: a health economics modelling analysis

Background

Early HIV diagnosis reduces morbidity, mortality, the probability of onward transmission, and their associated costs, but might increase cost because of earlier initiation of antiretroviral treatment (ART). We investigated this trade-off by estimating the cost-effectiveness of HIV screening in primary care.

Methods

We modelled the effect of the four-times higher diagnosis rate observed in the intervention arm of the RHIVA2 randomised controlled trial done in Hackney, London (UK), a borough with high HIV prevalence (≥0·2% adult prevalence). We constructed a dynamic, compartmental model representing incidence of infection and the effect of screening for HIV in general practices in Hackney. We assessed cost-effectiveness of the RHIVA2 trial by fitting model diagnosis rates to the trial data, parameterising with epidemiological and behavioural data from the literature when required, using trial testing costs and projecting future costs of treatment.

Findings

Over a 40 year time horizon, incremental cost-effectiveness ratios were £22 201 (95% credible interval 12 662–132 452) per quality-adjusted life-year (QALY) gained, £372 207 (268 162–1 903 385) per death averted, and £628 874 (434 902–4 740 724) per HIV transmission averted. Under this model scenario, with UK cost data, RHIVA2 would reach the upper National Institute for Health and Care Excellence cost-effectiveness threshold (about £30 000 per QALY gained) after 33 years. Scenarios using cost data from Canada (which indicate prolonged and even higher health-care costs for patients diagnosed late) suggest this threshold could be reached in as little as 13 years.

Interpretation

Screening for HIV in primary care has important public health benefits as well as clinical benefits. We predict it to be cost-effective in the UK in the medium term. However, this intervention might be cost-effective far sooner, and even cost-saving, in settings where long-term health-care costs of late-diagnosed patients in high-prevalence regions are much higher (≥60%) than those of patients diagnosed earlier. Screening for HIV in primary care is cost-effective and should be promoted.

Funding

NHS City and Hackney, UK Department of Health, National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care.

PrEP in Italy: The time may be ripe but who's paying the bill? A nationwide survey on physicians' attitudes towards using antiretrovirals to prevent HIV infection

Several studies have demonstrated the efficacy of the oral pre-exposure prophylaxis (PrEP) with tenofovir (with or without emtricitabine) on preventing HIV-negative partners of HIV infected patients to become infected through sexual contacts. PrEP is already available in the United States and now is approved by European Medicine Agency. In this setting we would like to gauge physicians' knowledge, acquaintance with and attitude to include PrEP in their clinical practice. A cross sectional survey was conducted among Italian physicians expert on antiretroviral therapy. Out of 146 physicians, 35% of participants declared to be familiar with PrEP but only 46% of them believed that, currently, there are not enough reasons to make it available in Italy. 51% of physicians have already been attracted to prescribe it and 63.4% have been openly asked about PrEP. The main concerns noticed were: the risk of acquire other sexual transmitted diseases (STDs) (70% of physicians feared that PrEP could favor STDs spread), the potential harmful of PrEP if not adequately implemented and, especially the risk of possible side effects if not properly used. Nevertheless, 55.9% of participants believed that Health Authorities face an ethical obligation to make PrEP available as part of the strategies to protect from HIV transmission and half of the respondents asked for further researches to better define the role for PrEP. Attitudes regarding PrEP impact on Italian National Health Organization were also very interesting: 57.5% of participants did not believe that investing in PrEP would be an appropriate use of healthcare resources, while 70.6% affirmed that PrEP's financial coverage should not be funded by the Italian National System of Health (SSN). This survey showed a high awareness of PrEP potential among Italian physicians coupled with a great deal of skepticism about how and if implementing it in clinical practice.

The Potential Cost-Effectiveness of Pre-Exposure Prophylaxis Combined with HIV Vaccines in the United States

This economic evaluation aims to support policy-making on the combined use of pre-exposure prophylaxis (PrEP) with HIV vaccines in development by evaluating the potential cost-effectiveness of implementation that would support the design of clinical trials for the assessment of combined product safety and efficacy. The target study population is a cohort of men who have sex with men (MSM) in the United States. Policy strategies considered include standard HIV prevention, daily oral PrEP, HIV vaccine, and their combination. We constructed a Markov model based on clinical trial data and the published literature. We used a payer perspective, monthly cycle length, a lifetime horizon, and a 3% discount rate. We assumed a price of $500 per HIV vaccine series in the base case. HIV vaccines dominated standard care and PrEP. At current prices, PrEP was not cost-effective alone or in combination. A combination strategy had the greatest health benefit but was not cost-effective (ICER = $463,448/QALY) as compared to vaccination alone. Sensitivity analyses suggest a combination may be valuable for higher-risk men with good adherence. Vaccine durability and PrEP drug prices were key drivers of cost-effectiveness. The results suggest that boosting potential may be key to HIV vaccine value.

Implementation of pre-exposure prophylaxis for human immunodeficiency virus infection: progress and emerging issues in research and policy

BACKGROUND

In this article, we present recent evidence from studies focused on the implementation, effectiveness and cost-effectiveness of pre-exposure prophylaxis (PrEP) for HIV infection; discuss PrEP scale-up to date, including the observed levels of access and policy development; and elaborate on key emerging policy and research issues to consider for further scale-up, with a special focus on lower-middle income countries.

DISCUSSION

The 2015 WHO Early Release Guidelines for HIV Treatment and Prevention reflect both scientific evidence and new policy perspectives. Those guidelines present a timely challenge to health systems for the scaling up of not only treatment for every person living with HIV infection but also the offer of PrEP to those at substantial risk. Delivery and uptake of both universal antiretroviral therapy (ART) and PrEP will require nation-wide commitment and could reinvigorate health systems to develop more comprehensive "combination prevention" programmes and support wider testing linked to both treatments and other prevention options for populations at highest risk who are currently not accessing services. Various gaps in current health systems will need to be addressed to achieve strategic scale-up of PrEP, including developing prioritization strategies, strengthening drug regulations, determining cost and funding sources, training health providers, supporting user adherence and creating demand.

CONCLUSIONS

The initial steps in the scale-up of PrEP globally suggest feasibility, acceptability and likely impact. However, to prevent setbacks in less well-resourced settings, countries will need to anticipate and address challenges such as operational and health systems barriers, drug cost and regulatory policies, health providers' openness to prescribing PrEP to populations at substantial risk, demand and legal and human rights issues. Emerging problems will require creative solutions and will continue to illustrate the complexity of PrEP implementation.

What do we know about the cost-effectiveness of HIV preexposure prophylaxis, and is it affordable?

PURPOSE OF REVIEW

The WHO recommends preexposure prophylaxis (PrEP) in populations at substantial risk of HIV. Despite a number of randomized controlled trials demonstrating its efficacy, and several ongoing implementation projects, PrEP is currently only available in a few countries. Modelling studies can provide useful insights into the long-term impact of introducing PrEP in different subgroups of the population. The review summarizes studies that either evaluated the cost-effectiveness or the cost of introducing PrEP, focusing on seven published in the last year.

RECENT FINDINGS

These studies used a number of different types of models and investigated the introduction of PrEP in different settings. Among men having sex with men (MSM) in North America, PrEP ranged from being cost-saving (while benefiting population health) to costing US $160,000/quality-adjusted life-year gained. Among heterosexual sero-different couples, it varied from around US $5000 to US $10,000/disability-adjusted life-year averted, when PrEP was used until 6 or 12 months after the HIV-positive partner had initiated antiretroviral therapy (ART) in, respectively, Uganda and South Africa.

SUMMARY

Future cost-effectiveness studies of PrEP should consider the HIV incidence, the level of uptake, the effect of its introduction on alternative prevention approaches, and the budget impact of rolling it out.

The European preexposure prophylaxis revolution

Purpose of review

The review describes the European epidemic and the challenges in moving from clinical trials of preexposure prophylaxis (PrEP) to routine practice.

Recent findings

Two European trials conducted in gay and other MSM and transgender women reported a high and consistent reduction in HIV incidence using oral PrEP with tenofovir/emtricitabine (TDF/FTC). The incidence of HIV infection in the control group was much higher than anticipated, based on routine surveillance data in MSM, in spite of the highest standard of HIV prevention available.

Summary

Recent results have highlighted the urgent need to make PrEP available to key populations in Europe as an additional prevention tool. Gilead has not yet submitted an application to use TDF/FTC as PrEP in Europe. Although regulatory approval would accelerate implementation, countries are already dispensing TDF/FTC as postexposure prophylaxis without this. Services for prevention are diverse across countries ranging from free, walk-in services for the diagnosis and treatment of HIV and other sexually transmitted infections, to insurance-dependent reimbursement of private clinical services. Momentum is gathering in Europe with PrEP demonstration projects in MSM and a growing demand from community organizations. Each Member State urgently needs to identify their key populations and determine the service best placed to provide this new prevention strategy within a comprehensive prevention package.

Impact of the Centers for Disease Control's HIV Preexposure Prophylaxis Guidelines for Men Who Have Sex With Men in the United States

BACKGROUND

 Preexposure prophylaxis (PrEP) is effective for preventing human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) within trial settings. Population impact will depend on clinical indications for PrEP initiation, coverage levels, and drug adherence. No modeling studies have estimated the impact of clinical practice guidelines for PrEP issued by the Centers for Disease Control and Prevention (CDC).

METHODS

 Mathematical models of HIV transmission among MSM were used to estimate the percentage of infections averted (PIA) and the number needed to treat (NNT) under behavioral indications of the CDC's PrEP guidelines. We modeled the contribution of these indications while varying treatment coverage and adherence.

RESULTS

 At 40% coverage of indicated MSM over the next decade, application of CDC guidelines would avert 1162 infections per 100 000 person-years, 33.0% of expected infections. The predicted NNT for the guidelines would be 25. Increasing coverage and adherence jointly raise the PIA, but reductions to the NNT were associated with better adherence only.

CONCLUSIONS

 Implementation of CDC PrEP guidelines would result in strong and sustained reductions in HIV incidence among MSM in the United States. The guidelines strike a good balance between epidemiological impact (PIA) and efficiency (NNT) at plausible scale-up levels. Adherence counseling could maximize public health investment in PrEP by decreasing the NNT.