CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

1056 Scale-up of Antiretroviral Therapy and Preexposure Prophylaxis in Swaziland Eugene T. Richardson 1 ; Futhi Dennis 2 ; Nokwazi Mathabela 2 ; Khanya Mabuza 2 ; AllenWaligo 2 ; Eran Bendavid 1 ; Sabina Alistar 1 ; Marelize Gorgens 3 ; FrancoisVenter 4 1 Stanford Univ, Stanford, CA, USA; 2 Natl Emergency Response Council on HIV and AIDS (NERCHA), Mbabane, Swaziland; 3 The World Bank, Washington, DC, USA; 4 Wits Reproductive Hlth and HIV Inst, Johannesburg, South Africa Background: With an adult prevalence of 31%, Swaziland has a severe, generalized HIV epidemic. Despite behavior change and other prevention programs, including scale-up of antiretroviral therapy (ART), new infections continue to be a problem, especially in young women (where incidence is 4.2%). The importance of population-specific combination prevention approaches to HIV has made mathematical modeling a necessary tool for planning efforts. As part of the evaluation of policy measures to end Swaziland’s HIV epidemic by 2030, we modeled the efficacy and cost effectiveness of various treatment and prevention strategies. Methods: Using demographic and epidemiological data from Swaziland, we constructed dynamic compartmental models as well as network models to assess the impact of ART scale-up as well as PrEP offered to 10% of the highest risk population over the next 15 years.

Results: Continuing the status quo—where ~$110 million is spent yearly on HIV programs and the median CD4 at initiation is 234—will yield 10.5 million quality-adjusted life years (QALYs) between 2015-30. For an added $110 million over 15 years, another 300,000 QALYs can be gained by offering PrEP to 10% of the highest risk population. This represents a cost of $366 per QALY gained. Compared to status quo, scale up of ART to CD4 < 350 yields an additional 800,000 QALYs at $288 per QALY gained, while universal ART coverage yields an additional 1.5 million QALYs at $327 per QALY gained. Figure 1 shows the potential benefit of PrEP delivered to one high-risk group in particular—young women—over the next 15 years. Conclusions: In the current setting of lowmedian CD4 at ART initiation, immediate role-out of PrEP to 10% of the highest risk population is very cost- effective at $366 per QALY gained. As the country gets to 100% test and treat, however, PREP is no longer cost effective. Since scale up of ART to universal coverage will take many years, there is impetus to roll out PREP to populations where both risk and PREP adherence are deemed to be highest. This strategy is also supported by the most recent WHO guidelines, which recommend offering PrEP “to people at substantial risk of HIV infection,” specified as >3% incidence. Given the significant preventive benefit of ART scale-up, however, an important caveat for PrEP programs is that they should be rolled out only if they do not detract from existing ART programs or future ART scale-up.

1057 Dapivirine Vaginal Ring Preexposure Prophylaxis for HIV Prevention in South Africa Robert Glaubius 1 ; Kerri J. Penrose 2 ; Greg Hood 3 ; Urvi M. Parikh 2 ; Ume Abbas 4

1 Cleveland Clinic, Cleveland, OH, USA; 2 Univ of Pittsburgh, Pittsburgh, PA, USA; 3 Pittsburgh Supercomputing Cntr, Pittsburgh, PA, USA; 4 Baylor Coll of Med, Houston, TX, USA Background: A vaginal ring (VR) containing dapivirine (DPV) is under evaluation for pre-exposure prophylaxis (PrEP) for HIV prevention among women. However, the potential impact and cost-effectiveness of DPV PrEP scale-up is unknown. Further, cross-resistance is common between DPV and first-line antiretroviral therapy (ART) in resource-limited settings. Methods: We modeled the HIV epidemic in KwaZulu-Natal, South Africa and compared the combined scale-up of ART, male medical circumcision (MMC) and DPV VR PrEP to a baseline scenario of just ART and MMC. We simulated four strategies of PrEP scale-up among women during 2017–2027: unprioritized (to 15–54 year-olds) or age-prioritized (to 15–24 or 20–29 year-olds) reaching 15% overall population-level coverage; or prioritized to female sex workers (FSWs) (~0.1% overall coverage). We examined scenarios of low (50%) or high (95%) average adherence, assuming 90% PrEP efficacy against wild-type and drug-resistant HIV, and 80% cross-resistance between ART and PrEP, and modeled HIV drug resistance dynamics in genital and blood compartments. We examined health outcomes and drug resistance consequences relative to baseline and calculated cost- effectiveness ratios while discounting healthcare and intervention costs (PrEP costs: $95/person-year) and health outcomes by 3% annually. Results: At low (50%) adherence, unprioritized DPV VR PrEP scale-up prevented 8.8% of (undiscounted) new infections over ten years at $8,678 per infection prevented. Impact and costs improved modestly with scale-up among women aged 15–24 (9.4% infections prevented, $8,059 per infection prevented) but more substantially when focused to women aged 20–29 (14.1%, $5,052). Scale-up among FSWs prevented the fewest infections overall (4.6%; given their small group size), but at lower cost, reducing the cumulative total costs by $21.4 million. At high (95%) compared to low adherence, HIV prevention increased by 86%–106% and cost-effectiveness ratios decreased by 52%–57% (Table). PrEP scale-up decreased prevalent drug-resistant cases at 2027 by 1.6%–7.4% and 4.4%–14.8% in the low and high adherence scenarios respectively; however, these decreases diminished by relative 2%–12%when in addition to blood, resistance was also tracked in the genital compartment. Conclusions: DPV VR PrEP could have considerable impact on HIV prevention at compelling economic value when prioritized to women by age and could decrease drug resistance, even if adherence is modest.

Poster Abstracts

453

CROI 2016