A week in review: CROI 2019

A week in review: CROI 2019

The 26th Conference on Retroviruses and Opportunistic Infections (CROI 2019) has just concluded in Seattle, Washington, United States. International AIDS Society (IAS) Members made dozens of presentations at the meeting. Here are a few of the stories that had attendees and the media talking.

Second HIV “cure” reported
Until now, researchers have not been able to duplicate the cure for HIV infection that Timothy Ray Brown (the “Berlin Patient”) experienced after receiving a bone marrow transplant from a donor with a rare genetic mutation on CCR5 leading to HIV resistance in 2007. At CROI 2019, however, Dr Ravindra Gupta of University College London presented the case of the “London Patient”, a formerly HIV-positive man who received a bone marrow transplant from a similarly immune donor as treatment for Hodgkin’s lymphoma and who has since remained without detectable HIV infection off antiretroviral therapy (ART) for 18 months.

The transplant that the London Patient underwent was less complex than the one that Brown experienced, but is still much too difficult to be used as an HIV treatment. Still, scientists were encouraged by the potential insights into HIV cure approaches that this discovery could lead to.

“These new findings reaffirm our belief that there exists a proof of concept that HIV is curable,” IAS President Anton Pozniak said in a statement. “The hope is that this will eventually lead to a safe, cost-effective and easy strategy to achieve these results using gene technology or antibody techniques.”

Proving the benefits of intensive testing and treatment
The long-awaited results of the PopART study (“Population Effects of Antiretroviral Therapy to Reduce HIV Transmission”), released at CROI, showed that a package of services, including house-to-house voluntary testing, rapid access to treatment and enhanced prevention for people who test HIV negative, led to a 30% drop in new infections. The study, which involved nearly 50,000 people in 21 cities and towns across South Africa and Zambia, gives new scientific weight to the idea that population-wide home-based testing and enhanced access to treatment and prevention services can lead to sharp declines in the epidemic.

In another CROI presentation, researcher Emily Zielinski-Gutierez from the United States Centers for Disease Control and Prevention outlined the dramatic declines in HIV mortality that accompanied widespread access to treatment in Kenya, and offered recommendations for enhanced tracking systems to track the population-wide benefits of expanding access to ART.

The extraordinary promise of broadly neutralizing antibodies (bNAbs)
Researchers were excited about the HIV prevention and treatment potential of bNAbs. These very potent antibodies, which are developed naturally by a small number of people living with HIV and can be cloned by researchers, are being studied for their potential use in HIV vaccines, treatment and pre-exposure prophylaxis (PrEP). In the CROI keynote presentation, “Discovery and Development of HIV Broadly Neutralizing Antibodies”, Michel Nussenzweig, of New York’s Rockefeller University, presented an overview of strategies to deploy these powerful antibodies in a variety of ways against the epidemic.

Other highlights of new bNAbs research included: studies looking at engineered “trispecific” antibodies that use three separate approaches to block HIV; strategies to overcome viral evasion of bNAbs and enhance their effectiveness; and the first evidence that a bNAb can protect against penile infection in macaques, which, building on previous evidence of their effectiveness against rectal and vaginal infection in macaques, raises the prospect that bNAbs could also be used in the development of long-acting PrEP.

TB treatments improve, even for the hardest to treat cases
Tuberculosis is the leading global cause of death for people living with HIV, and drug-resistant TB has made the challenges of TB treatment even greater. For the second year in a row, however, attendees at CROI heard encouraging news about emerging treatment approaches that could help reduce the global burden of TB.

Research from the Tshepiso Cohort offered encouraging evidence that isoniazid preventive therapy (IPT) can safely prevent TB disease in HIV-positive pregnant women, a group at very high risk for TB in many settings. A South African study showed that the HIV antiretroviral, dolutegravir, can be safely used alongside 3HP, a short-course preventive therapy for TB consisting of rifapentine and isoniazid weekly for 3 months for both adults and children in countries with a high TB incidence. And data from the DELIBERATE trial showed that bedaquiline and delamanid, the first drugs of new classes approved for TB treatment in 40 years, passed an important safety test for use in individuals with multidrug-resistant forms of TB.

Together, these reports important steps forward in efforts to untangle the impact of the interconnected epidemics of HIV and TB.

New results in HIV prevention and treatment
“We’re entering a brave new world in HIV prevention,” meeting Co-Chair Sharon Hillier said while moderating a CROI press conference panel that included results from the largest HIV prevention study to date. The DISCOVER study, which compared two forms of oral PrEP (FTC/TDF vs FTC/TAF), involved more than 5,300 participants at high risk for HIV infection, but recorded only 22 new HIV infections, and only two in individuals who achieved intermediate or expected levels of PrEP drugs in their systems. Attendees also heard about significant remaining challenges in getting PrEP to those who need it most and in supporting those who start PrEP to continue its use.

Other HIV prevention advances at CROI included promising new data from non-human primates on vaginal inserts for prevention.

On the treatment side, results from two Phase 3 studies of long-acting treatment with cabotegravir and rilpivirine, ATLAS and FLAIR, support the development of monthly injections as an alternative to daily oral treatment for people living with HIV. And early data on a sustained delivery implant approach to therapy offered the prospect of new approaches in HIV treatment.

Looking ahead, we are excited to build upon the research and science from this week at the 10th IAS Conference on HIV Science in Mexico City (IAS 2019). Register today and join us this July.