Heather Boerner

February 07, 2017

SEATTLE — When controversies arise, researchers return to the science. So at the Conference on Retroviruses and Opportunistic Infections (CROI) 2017, which will convene next week amid funding concerns and boycotts, researchers will be diving deep into the evidence.

"Now is not the time to take our foot off the gas," said Susan Buchbinder, MD, from the University of California, San Francisco, who is chair of the CROI conference committee. "We're at a critical juncture. We need to increase our efforts to realize the benefits of new testing technology, better therapies, and dissemination of treatment," she told Medscape Medical News.

To that end, presentations at the meeting will address the challenges that remain in the field of HIV, including how to reach vulnerable populations.

The meeting will convene under a cloud of controversy over US President Donald Trump's executive order on immigration and uncertainty about the future of funding for HIV and microbicide research, much of which currently comes from the National Institutes of Health (NIH) and the President's Emergency Plan for AIDS Relief.

Convening Amid Controversy

This is nothing new for CROI, which was established amid controversy. In 1992, the International AIDS Conference, set to convene in Boston, was canceled as researchers and activists protested another travel ban — a 1987 ban against people with HIV traveling to the United States without disclosing their status.

The inaugural CROI conference was held the next year.

A CROI statement issued this year in response to an international boycott signed by more than 6000 academics states that the conference "strongly opposes arbitrary travel restrictions based solely on religion or national origin" and will assist travelers affected by the order.

The meeting will tackle one of the thorniest challenges in HIV: how to improve prevention and treatment for the most vulnerable people in the United States and in other regions.

Although many Americans have access to HIV pre-exposure prophylaxis (PrEP), the majority are white, middle-class men with private insurance. Access to PrEP needs to be improved in other populations, Dr Buchbinder pointed out.

Reaching Vulnerable Populations

In one presentation, researchers from the Centers for Disease Control and Prevention will address the expansion of viral suppression in young people and in people of color. And in one of the plenary sessions, the model being used in New York City to end the HIV epidemic will be highlighted.

In sub-Saharan Africa, the risk for a renewed HIV epidemic among young people, related to a population bulge, has highlighted the need for wider access to prophylaxis. "A number of studies will show what it looks like on the ground — in terms of testing, treatment, PrEP, voluntary medical male circumcision, and innovative strategies — at a relatively low cost," Dr Buchbinder explained.

"We're going to see, side by side, how the United States and resource-limited settings are doing, and what we can learn from both settings," she said.

Several studies — looking at the role of the vaginal microbiome, contraceptives, and risk factors in HIV prevention — will address a core question: "What's protective and what's actually bad?" said Sharon Hillier, MD, from Magee–Womens Hospital at the University of Pittsburgh Medical Center, who is a member of the scientific program committee.

Results on the impact of vaginal microflora diversity on topical HIV prevention, presented last year at the International AIDS Conference, will be updated by the team from the Centre for the AIDS Programme of Research in South Africa.

In another session, researchers will look at whether the vaginal microbiome has an impact on the protective effect of oral PrEP in women. The nuance of vaginal bacteria and HIV susceptibility will be addressed by Scott McClelland, MD, from the University of Toronto, who will look at "the complexity of understanding of which micro-organisms are driving enhanced HIV risk," Dr Hillier reported.

The potential impact of the "long tail" problem related to injectable cabotegravir (ViiV Healthcare), a novel HIV prevention therapy, will be discussed, and animal data will be presented on whether long-lived subclinical levels of cabotegravir can lead to drug resistance.

"Everyone wants a magic bullet," said Dr Hillier, "but we should never be too wide-eyed. We have to look at the risk factors, including the induction of resistance."

Potential Practice-Changing Presentations

A number of presentations — in HIV, tuberculosis, and the Zika virus — could provide practice-changing data.

The SWORD-1 and SWORD-2 studies will look at whether a simplified two-drug antiretroviral regimen — dolutegravir and rilpivirine — is as effective as the standard three-drug regimen for viral suppression.

There will also be presentations on multidrug-resistant tuberculosis, which "could be very important clinically," Dr Buchbinder pointed out.

Other presentations will address key clinical questions about the Zika virus, including how long the virus survives in different bodily fluids and the neurologic effects of the virus on newborns.

Back to Basic Science

During a late-breaker session, NIH researchers will build on the durable-suppression data presented at HIV Research for Prevention (HIVR4P) 2016 by Anthony Fauci, MD, director of the National Institute for Allergy and Infectious Disease.

During that presentation, Dr Fauci unveiled data showing that standard antiretroviral therapy followed by infusion with an antibody against the cell receptor alpha4beta7 integrin leads to durable viral suppression without cure in monkeys. The update presented this year by a member of Dr Fauci's team might help explain the mechanism of action.

It's a step in the direction of suppression without daily antiretroviral therapy, Dr Fauci told Medscape Medical News. "We don't know if it's the mechanism, but it's a potential mechanism. We're going to try it in humans."

Dr Buchbinder reports receiving funding from the NIH and conducting studies for which Gilead Science provided the study drug. Dr Hillier and Dr Fauci have disclosed no relevant financial relationships.


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