International AIDS Society

Systematic Review Outlines Limits, Benefits of PrEP in Africa, US, Peru

Author: Mark Mascolini

30 April 2013

Systematic review of literature published through January 2013 determined that preexposure prophylaxis (PrEP) with antiretrovirals may be cost-effective in certain circumstances. But the cost of antiretrovirals often proved a limiting factor.

Four randomized trials found that oral or vaginal gel tenofovir-based PrEP can protect people from HIV infection, while two trials did not. In an attempt to understand the cost and expected impact of PrEP in various populations, researchers conducted a systematic review of modeling studies analyzing the epidemiologic impact and cost-effectiveness of PrEP.

The researchers identified 13 studies involving heterosexual couples, men who have sex with men (MSM), or injection drug users in southern Africa, Ukraine, the United States, and Peru. In general, they found that “the extent of the impact of PrEP depended upon assumptions made concerning cost, epidemic context, programme coverage, prioritisation strategies, and individual-level adherence.”

Seven studies focusing on PrEP in generalized HIV epidemics in southern Africa suggested that PrEP may be cost-effective in preventing heterosexual transmission. But the authors noted that funding PrEP raises concerns if other cost-effective HIV prevention strategies remain underfunded.

Five studies assessing PrEP for concentrated epidemics in MSM in the United States and Peru suggested PrEP could have a large impact on the HIV epidemic among these men but may not be affordable at current drug prices.

One study evaluating PrEP among injection drug users in Ukraine determined that PrEP would not be cost-effective in that context.

Antiretroviral costs proved a limiting factor in all settings analyzed. The studies reviewed indicated that behavior change and adherence to PrEP could have substantial impacts on the effectiveness of this prevention strategy. But emergence of virus resistant to antiretrovirals during PrEP use and PrEP-related toxicity did not have a significant impact on cost-effectiveness.

The authors believe their review “identifies the main considerations to address in assessing cost-effectiveness analyses of a PrEP intervention—cost, epidemic context, individual adherence level, PrEP programme coverage, and prioritisation strategy.”

Source: Gabriela B. Gomez, Annick Borquez, Kelsey K. Case, Ana Wheelock, Anna Vassall, Catherine Hankins. The cost and impact of scaling up pre-exposure prophylaxis for HIV prevention: a systematic review of cost-effectiveness modelling studies. PLoS Medicine. 2013; 10: e1001401.

Complete article provided by PLoS Medicine, an open-access journal