Epidemiological impact and cost-effectiveness of providing long-acting pre-exposure prophylaxis to injectable contraceptive users for HIV prevention in South Africa: a modelling study.
ABSTRACT: INTRODUCTION:Although pre-exposure prophylaxis (PrEP.) is an efficacious HIV prevention strategy, its preventive benefit has not been shown among young women in sub-Saharan Africa, likely due to non-adherence. Adherence may be improved with the use of injectable long-acting PrEP methods currently being developed. We hypothesize that providing long-acting PrEP to women using injectable contraceptives, the most frequently used contraceptive method in South Africa, could improve adherence to PrEP, result in a reduction of new HIV infections, and be a relatively easy-to-reach target population. In this modelling study, we assessed the epidemiological impact and cost-effectiveness of providing long-acting PrEP to injectable contraceptive users in Limpopo, South Africa. METHODS:We developed a deterministic mathematical model calibrated to the HIV epidemic in Limpopo. Long-acting PrEP was provided to 50% of HIV negative injectable contraceptive users in 2018 and scaled-up over two years. We estimated the number of HIV infections that could be averted by 2030 and the drug price of long-acting PrEP for which this intervention would be cost-effective over a time horizon of 40 years, from a healthcare payer perspective. In the base-case scenario we assumed long-acting PrEP is 75% effective in preventing HIV infections and 85% of infected individuals are on antiretroviral drug therapy (ART) by 2030. In sensitivity analyses we adjusted PrEP effectiveness and ART coverage. Costs between $519 and $1119 per disability-adjusted life-year (DALY) averted were considered potentially cost-effective, and <$519 as cost-effective. RESULTS:Without long-acting injectable PrEP, 224,000 (interquartile range 176,000 to 271,000) new infections will occur by 2030; use of long-acting injectable PrEP could prevent 21,000 (17,000 to 26,000) or 9.8% (8.9% to 10.6%) new HIV infections by 2030 (including 6000 (4000 to 7000) in men). Long-acting PrEP would prevent 34,000 (29,000 to 39,000) or 12,000 (8000 to 15,000) at 75% and 95% ART coverage by 2030 respectively. To be considered potentially cost-effective the annual long-acting PrEP drug price should be <$16, and/or ART coverage remains at <85% in 2030. CONCLUSIONS:Providing long-acting PrEP to injectable contraceptive users in Limpopo is only potentially cost-effective when long-acting PrEP drug prices are low. If low prices are not feasible, providing long-acting PrEP only to women at high risk of HIV infection will become important.
Project description:BACKGROUND:For young South African women at risk for human immunodeficiency virus (HIV) infection, preexposure prophylaxis (PrEP) is one of the few effective prevention options available. Long-acting injectable PrEP, which is in development, may be associated with greater adherence, compared with that for existing standard oral PrEP formulations, but its likely clinical benefits and additional costs are unknown. METHODS:Using a computer simulation, we compared the following 3 PrEP strategies: no PrEP, standard PrEP (effectiveness, 62%; cost per patient, $150/year), and long-acting PrEP (effectiveness, 75%; cost per patient, $220/year) in South African women at high risk for HIV infection (incidence of HIV infection, 5%/year). We examined the sensitivity of the strategies to changes in key input parameters among several outcome measures, including deaths averted and program cost over a 5-year period; lifetime HIV infection risk, survival rate, and program cost and cost-effectiveness; and budget impact. RESULTS:Compared with no PrEP, standard PrEP and long-acting PrEP cost $580 and $870 more per woman, respectively, and averted 15 and 16 deaths per 1000 women at high risk for infection, respectively, over 5 years. Measured on a lifetime basis, both standard PrEP and long-acting PrEP were cost saving, compared with no PrEP. Compared with standard PrEP, long-acting PrEP was very cost-effective ($150/life-year saved) except under the most pessimistic assumptions. Over 5 years, long-acting PrEP cost $1.6 billion when provided to 50% of eligible women. CONCLUSIONS:Currently available standard PrEP is a cost-saving intervention whose delivery should be expanded and optimized. Long-acting PrEP will likely be a very cost-effective improvement over standard PrEP but may require novel financing mechanisms that bring short-term fiscal planning efforts into closer alignment with longer-term societal objectives.
Project description:BACKGROUND:Oral pre-exposure prophylaxis (PrEP) prevents HIV infection in men who have sex with men (MSM); however, adherence is an ongoing concern. Long-acting injectable PrEP is being tested in phase 3 trials and could address challenges associated with adherence. We examined the potential effectiveness of long-acting injectable PrEP compared with oral PrEP in MSM. METHODS:We used an agent-based model to simulate HIV transmission in a dynamic network of 11?245 MSM in Atlanta, GA, USA. We used raw data from studies in macaque models and pharmacokinetic data from safety trials to estimate the time-varying efficacy of long-acting injectable PrEP. The effect of long-acting injectable PrEP on the cumulative number of new HIV infections over 10 years (2015-24) was compared with no PrEP and daily oral PrEP across a range of coverage levels. Sensitivity analyses were done with varying maximum efficacy and drug half-life values. FINDINGS:In the absence of PrEP, the model predicted 2374 new HIV infections (95% simulation interval [SI] 2345-2412) between 2015 and 2024. The cumulative number of new HIV infections was reduced in all scenarios in which MSM received long-acting injectable PrEP compared with oral PrEP. At a coverage level of 35%, compared with no PrEP, long-acting injectable PrEP led to a 44% reduction in new HIV infections (1044 new infections averted [95% SI 1018-1077]) versus 33% (792 infections averted [763-821]) for oral PrEP. The relative benefit of long-acting injectable PrEP was sensitive to the assumed efficacy of injections received every 8 weeks, discontinuation rates, and terminal drug half-life. INTERPRETATION:Long-acting injectable PrEP has the potential to produce larger reductions in HIV transmission in MSM than oral PrEP. However, the real-world, population-level impact of this approach will depend on uptake of this prevention method and its effectiveness, as well as retention of patients in clinical care. FUNDING:National Institute on Drug Abuse and National Institute of Mental Health.
Project description:Background. ?A long-acting injectable formulation of rilpivirine (RPV), under investigation as antiretroviral pre-exposure prophylaxis (PrEP), may facilitate PrEP adherence. In contrast, cross-resistance between RPV and nonnucleoside reverse-transcriptase inhibitors comprising first-line antiretroviral therapy (ART) could promote human immunodeficiency virus (HIV) drug resistance and reduce PrEP's effectiveness. Methods. ?We use novel mathematical modeling of different RPV PrEP scale-up strategies in KwaZulu-Natal, South Africa, to investigate their effects on HIV prevention and drug resistance, compared with a reference scenario without PrEP. Results. ?Pre-exposure prophylaxis scale-up modestly increases the proportion of prevalent drug-resistant infections, from 33% to ?37%. The change in the number of prevalent drug-resistant infections depends on the interplay between PrEP factors (coverage, efficacy, delivery reliability, and scale-up strategy) and the level of cross-resistance between PrEP and ART. An optimistic scenario of 70% effective RPV PrEP (90% efficacious and 80% reliable delivery), among women aged 20-29 years, prevents 17% of cumulative infections over 10 years while decreasing prevalent resistance; however, prevention decreases and resistance increases with more conservative assumptions. Uncertainty analysis assuming 40%-70% cross-resistance prevalence predicts an increase in prevalent resistance unless PrEP's effectiveness exceeds 90%. Conclusions. ?Prioritized scale-up of injectable PrEP among women in KwaZulu-Natal could reduce HIV infections, but suboptimal effectiveness could promote the spread of drug resistance.
Project description:<label>BACKGROUND</label>Long-acting injectable antiretrovirals such as rilpivirine (RPV) could promote adherence to preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) prevention. However, the cost-effectiveness of injectable PrEP is unclear.<label>METHODS</label>We constructed a dynamic model of the heterosexual HIV epidemic in KwaZulu-Natal, South Africa, and analyzed scenarios of RPV PrEP scale-up for combination HIV prevention in comparison with a reference scenario without PrEP. We estimated new HIV infections, life-years and costs, and incremental cost-effectiveness ratios (ICERs), over 10-year and lifetime horizons, assuming a societal perspective.<label>RESULTS</label>Compared with no PrEP, unprioritized scale-up of RVP PrEP covering 2.5%-15% of adults prevented up to 9% of new infections over 10 years. HIV prevention doubled (17%) when the same coverage was prioritized to 20- to 29-year-old women, costing $10 880-$19 213 per infection prevented. Prioritization of PrEP to 80% of individuals at highest behavioral risk achieved comparable prevention (4%-8%) at <1% overall coverage, costing $298-$1242 per infection prevented. Over lifetime, PrEP scale-up among 20- to 29-year-old women was very cost-effective (<$1600 per life-year gained), dominating unprioritized PrEP, while risk prioritization was cost-saving. PrEP's 10-year impact decreased by almost 50% with increases in ICERs (up to 4.2-fold) in conservative base-case analysis. Sensitivity analysis identified PrEP's costs, efficacy, and reliability of delivery as the principal drivers of uncertainty in PrEP's cost-effectiveness, and PrEP remained cost-effective under the assumption of universal access to second-line antiretroviral therapy.<label>CONCLUSIONS</label>Compared with no PrEP, prioritized scale-up of RPV PrEP in KwaZulu-Natal could be very cost-effective or cost-saving, but suboptimal PrEP would erode benefits and increase costs.
Project description:INTRODUCTION:High HIV incidence and low adherence to daily oral PrEP among women underscore the need for more acceptable and easier to use HIV prevention products. Global demand for injectable contraception suggests that new, long-acting, injectable formulations could meet this need. We examine acceptability of a long-acting injectable PrEP among HIV-uninfected women in Zimbabwe, South Africa and two United States phase 2 trial sites. METHODS:Quantitative surveys were administered at the first, fourth and sixth injection visits. Focus group discussions (FGD) were conducted after the sixth injection visit. We compared the acceptability of injectable product attributes, prevention preferences and future interest in injectable PrEP by site and arm and ran longitudinal ordinal logistic regression models to identify determinants of future interest in injectable PrEP. RESULTS:Between April 2015 and February 2017, the trial enrolled 136 (100 African, 36 US) women with a median age of 31 years. Most participants (>75%) rated injectable attributes as very acceptable. While few reported rash or other side effects, 56% to 67% reported injection pain, with nonsignificant differences over time and between arms. During FGDs, participants described initial fear of the injectable and variable experiences with pain. Most US and African participants preferred injectable PrEP to daily oral pills (56% to 96% vs. 4% to 25%). Future interest in using injectable PrEP was associated with acceptability of product attributes and was higher in African than US sites. In FGDs, participants described multiple reasons for trial participation, including a combination of monetary, health-related and altruistic motivations. While associated with future interest in use in univariate models, neither altruistic nor personal motivations remained significant in the multivariate model. CONCLUSIONS:This study found that long-acting injectable PrEP is acceptable among African and US women experiencing product use. Acceptability of product attributes better predicted future interest in injectable use than experience of pain. This is reassuring as a single-dose regimen of a different product has advanced to phase 3 trials. Finally, the study suggests that future demand for an injectable PrEP by women may be greater in African than US settings, where the risk of HIV is highest.
Project description:Background:Despite high efficacy of oral antiretroviral therapy (ART), viral suppression among adolescents and young adults (AYA) living with HIV in sub-Saharan Africa (SSA) remains low. Compared to daily oral ART, bimonthly long-acting injectable ART (LA-ART) may simplify adherence, improve clinical outcomes, and decrease HIV transmission in this priority population. However, LA-ART will likely cost more than oral ART and the cost threshold at which LA-ART will be cost effective in SSA has not been evaluated. Methods:We adapted a mathematical model of HIV transmission and progression in Kenya to include HIV acquisition and viral suppression among AYA (age 10-24). We projected the population-level health and economic impact of providing LA-ART to AYA over a 10-year time horizon assuming oral ART costs of US$233 annually and a two-month duration of viral suppression per LA-ART injection. We calculated the maximum cost at which switching from oral to LA-ART would be considered cost-effective, using thresholds of $500 and $1,508 per disability-adjusted life year averted (WHO's threshold of HIV treatment interventions and Kenya's gross domestic product per capita). Findings:Assuming 85% of AYA switch from oral to injectable formulations, LA-ART is estimated to prevent 40,540 infections and 20,480 deaths over 10 years. The maximum increase in the annual per-person cost of receiving LA-ART is estimated to be $89 and $236 for LA-ART to be cost-effective under the thresholds of $500 and $1,508 per DALY averted, respectively. The cost threshold was lower when non-adherent oral ART AYA users were assumed to be less likely to switch to LA-ART. Interpretation:Providing LA-ART to AYA can be cost-effective in Kenya if it is less than twice the cost of oral ART. Long-acting injectable ART for priority populations with low viral suppression has the potential to cost-effectively avert disability and death. Funding:National Institutes of Health (R01 HD085807; PI: Kohler).
Project description:Importance:The 2019 federal Ending the HIV Epidemic initiative requires a vast expansion of access to antiretroviral therapy (ART) and preexposure prophylaxis (PrEP) for HIV treatment and prevention. However, high prices for ART and PrEP can reduce their affordability and use. Medicare covers 1 in 4 persons living with HIV, and the Medicare Part D drug benefit imposes complicated cost-sharing between patients and other stakeholders. Objective:To determine how the Medicare Part D design distributes the cost burden for ART and PrEP between patients, insurance plans, manufacturers, and Medicare. Design and Setting:Nationwide cross-sectional analyses of first quarter 2019 Medicare formulary and pricing files for 3326 Part D plans were performed. These files contain drug benefit data, including prices and cost-sharing requirements. Main Outcomes and Measures:For 18 ART and 2 PrEP regimens, the out-of-pocket costs for patients and the cost borne by plans, manufacturers, and Medicare were projected for 1 year of treatment or prevention under a 2019 standard Medicare Part D insurance plan. Analyses assumed that patients used the ART or PrEP regimen and no other medications. Results:In 2019, ART prices ranged from $24?010 to $46?770 annually (median price, $35?780), with patients projected to pay 9% to 14% of the cost ($3270-$4350), insurance plans 18% to 24% ($5340-$8450), manufacturers 6% to 11% ($2370-$2750), and Medicare 53% to 67% ($12?770-$31?270). The price of PrEP was $20?570 annually, with patients contributing 15% ($2990), insurance plans 22% ($4570), manufacturers 13% ($2750), and Medicare 50% ($10?260). For beneficiaries with low-income subsidies that cover all patient cost-sharing, Medicare would assume 67% to 76% of ART costs and 65% of PrEP costs. Conclusions and Relevance:Medicare Part D mandates universal ART and PrEP coverage, but high prices (>$35?000 annually for ART and>$20?000 annually for PrEP) and the design of Part D can jeopardize affordability for patients and place most of the cost burden on taxpayers. Under a standard Medicare Part D benefit, patients pay $3000 to $4000 out-of-pocket yearly, unless they qualify for low-income subsidies, and half to two-thirds of the cost of ART and PrEP is borne by Medicare rather than insurance plans or manufacturers. To end the HIV epidemic by 2030, it appears that policies must address both high drug prices and revamp Medicare Part D cost-sharing.
Project description:<h4>Background</h4>Antiretrovirals have substantial promise for HIV-1 prevention, either as antiretroviral treatment (ART) for HIV-1-infected persons to reduce infectiousness, or as pre-exposure prophylaxis (PrEP) for HIV-1-uninfected persons to reduce the possibility of infection with HIV-1. HIV-1 serodiscordant couples in long-term partnerships (one member is infected and the other is uninfected) are a priority for prevention interventions. Earlier ART and PrEP might both reduce HIV-1 transmission in this group, but the merits and synergies of these different approaches have not been analyzed.<h4>Methods and findings</h4>We constructed a mathematical model to examine the impact and cost-effectiveness of different strategies, including earlier initiation of ART and/or PrEP, for HIV-1 prevention for serodiscordant couples. Although the cost of PrEP is high, the cost per infection averted is significantly offset by future savings in lifelong treatment, especially among couples with multiple partners, low condom use, and a high risk of transmission. In some situations, highly effective PrEP could be cost-saving overall. To keep couples alive and without a new infection, providing PrEP to the uninfected partner could be at least as cost-effective as initiating ART earlier in the infected partner, if the annual cost of PrEP is <40% of the annual cost of ART and PrEP is >70% effective.<h4>Conclusions</h4>Strategic use of PrEP and ART could substantially and cost-effectively reduce HIV-1 transmission in HIV-1 serodiscordant couples. New and forthcoming data on the efficacy of PrEP, the cost of delivery of ART and PrEP, and couples behaviours and preferences will be critical for optimizing the use of antiretrovirals for HIV-1 prevention. Please see later in the article for the Editors' Summary.
Project description:Pre-exposure prophylaxis (PrEP) is effective in preventing HIV infections among men who have sex with men (MSM). PrEP uptake and adherence remain low and product preferences are unknown, especially among young African American MSM who are most at-risk. We conducted 26 qualitative interviews from 2014-2016 among young adult HIV-negative African American MSM regarding PrEP product preferences in Missouri. While the pill and injectable were most liked of all modalities, about a quarter preferred rectal products or patches. Most participants preferred a long-acting injectable (LAI) to daily oral pills due to better medication adherence and a dislike for taking pills. Many participants preferred daily oral pills to on-demand oral PrEP due to the inability to predict sex and the perception that insufficient time or medication would not achieve HIV protection with on-demand. A fear of needles and the perception that there would not be therapeutic levels for a long duration were concerns with injectable PrEP. Study findings highlight the need for a range of prevention options for African American MSM and can inform PrEP product development as well as dissemination and implementation efforts.
Project description:Many ways of preventing HIV infection have been proposed and more are being developed. We sought to construct a strategic approach to HIV prevention that would use limited resources to achieve the greatest possible prevention impact through the use of interventions available today and in the coming years.We developed a deterministic compartmental model of heterosexual HIV transmission in South Africa and formed assumptions about the costs and effects of a range of interventions, encompassing the further scale-up of existing interventions (promoting condom use, male circumcision, early antiretroviral therapy [ART] initiation for all [including increased HIV testing and counselling activities], and oral pre-exposure prophylaxis [PrEP]), the introduction of new interventions in the medium term (offering intravaginal rings, long-acting injectable antiretroviral drugs) and long term (vaccine, broadly neutralising antibodies [bNAbs]). We examined how available resources could be allocated across these interventions to achieve maximum impact, and assessed how this would be affected by the failure of the interventions to be developed or scaled up.If all interventions are available, the optimum mix would place great emphasis on the following: scale-up of male circumcision and early ART initiation with outreach testing, as these are available immediately and assumed to be low cost and highly efficacious; intravaginal rings targeted to sex workers; and vaccines, as these can achieve a large effect if scaled up even if imperfectly efficacious. The optimum mix would rely less on longer term developments, such as long-acting antiretroviral drugs and bNAbs, unless the costs of these reduced. However, if impossible to scale up existing interventions to the extent assumed, emphasis on oral PrEP, intravaginal rings, and long-acting antiretroviral drugs would increase. The long-term effect on the epidemic is most affected by scale-up of existing interventions and the successful development of a vaccine.With current information, a strategic approach in which limited resources are used to maximise prevention impact would focus on strengthening the scale-up of existing interventions, while pursuing a workable vaccine and developing other approaches that can be used if further scale-up of existing interventions is limited.Bill & Melinda Gates Foundation.