Track C report by Adaora A. Adimora
Nancy Padian focused on implementation science issues related to use of ART for prevention. Use of ART for prevention will require increased human resources, structural resources, and commodities, such as test kits and drugs. Substantial increases in HIV testing will be required. There is a particular need for an acute infection incidence assay, given the marked risk of transmission during this phase of infection. Adherence remains a major challenge. Innovative strategies are needed for monitoring adherence in real time. Products are needed that require lower adherence (rings, implants, patches) and are better tolerated. We will need to resolve how distribution of ART is prioritized. Ensuring equity will be a challenge, as treatment is not yet available to all who need it.
Ian McGowan reviewed oral and topical antiretroviral prophylaxis. One benefit of topical antiretroviral administration is attainment of high drug levels at the site of administration. Several animal studies have demonstrated proof of concept of the potential efficacy of rectal microbicides’ potential efficacy in preventing HIV infection. Phase 1 studies in human are underway. Studies are also currently evaluating viral resistance, differences between oral and topical PrEP in safety and efficacy, and use of topical PrEP during adolescence and pregnancy. Use of ART for PrEP involves several challenges: increasing adherence, obtaining licensure for tenofovir 1% gel, bridging between the end of PrEP effectiveness trials and community availability of PrEP agents, and reducing the cost of delivering PrEP. Future research priorities include development of rectal microbicides, evaluation of extended release PrEP agents, combination HIV prevention strategies, and implementation of research findings.
Mitchell Warren discussed the future of treatment and prevention. He stressed the need for prevention that combines all available intervention modes: behavioral interventions, HIV counseling and testing, male and female condom use, STI treatment, male circumcision, effective topical microbicides, treatment for prevention, positive behavioral prevention, pre-exposure prophylaxis, post-exposure prophylaxis, and vaccines and presented a time line for rolling out interventions available, noting that scientific data do not change the world – programs and policies backed by civil society, donors, implementer, and governments do.
Tim Farley discussed regulatory issues related to licensing of ART for new indications. Discussions concerning regulatory approval for new indications are underway between US and European drug regulating agencies and pharmaceutical companies that hold marketing authorization, patents, and/or licenses for oral and topical antiretrovirals with demonstrated efficacy in preventing HIV infection. The daily cost of Viread in the US is about $23, the price for low/middle income countries is $1.00, compared to $0.21 for the generic drug (tenofovir). This price differential is reportedly required for intellectual property return on investment and incentive for innovation. An audience member, noting the substantial proportions of HIV-infected adults in the US who cannot afford ART, expressed concerns about the high cost of drugs in that country. He asked how the pharmaceutical company had managed not to recoup its investments already, given the huge number of patients in the US who had been treated with Viread and Truvada.