Infectious Disease

For the primary time, researchers say infusions of antibodies can forestall HIV an infection

January 26, 2021

3 min read

Source / information

Source:

Corey L et al. Abstract 1480. Presented at: HIV Research for Prevention; 27.-28. January and 3-4. February 2021 (virtual meeting).

Disclosure:
Fauci does not report any relevant financial information. Healio was unable to confirm any financial information for Corey or Mgodi at the time of publication.

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The researchers showed for the first time that antibodies can prevent HIV infection.

According to clinical trial results presented at the HIV Research for Prevention virtual meeting, infusions of a largely neutralizing antibody (bNAb) called VRC01 were effective in preventing infection with strains of HIV susceptible to the antibody, even though the infusions did not provide protection against non-susceptible strains.

Paul antibody quote

“The study as a concept test was wonderfully successful and sets the milestone that we can use largely neutralizing antibodies to prevent HIV.” Lawrence Corey, MD, President and director emeritus of the Fred Hutchinson Cancer Research Center said during a news conference.

“This will be a new modality and toolbox that will open the field for antibody cocktails and monoclonal antibody development,” said Corey, protocol director of Antibody-Mediated Prevention (AMP) studies and principal researcher for the HIV Vaccine Trials Network (HVTN ).

Seventy-five percent effective

In a study, Corey and colleagues included around 2,700 transgender and cisgender men who have sex with men in Brazil, Peru, Switzerland, and the United States. Another study included more than 1,900 HIV-negative cisgender women in seven African countries – Botswana, Kenya, Malawi, Mozambique, South Africa, Tanzania and Zimbabwe. Participants received an intravenous infusion of VRC01 at a dose of either 10 mg / kg or 30 mg / kg or a placebo every 8 weeks for 80 weeks. They were screened for HIV acquisition at 4 week intervals.

VRC01 was calculated to be 75% effective in preventing HIV infection from isolates sensitive to the antibody. However, since only 30% of the isolates were sensitive to the antibody, overall protection from VRC01 was not statistically significant compared to placebo, the researchers reported.

Komfort M. Mgodi, MBChB, MMed, a researcher in the VRC01 studies, At a web concert before the conference, they told journalists that they wanted to answer four questions: “Is VRC01 safe for people? Can people tolerate the antibody without feeling too uncomfortable? Does the antibody reduce the chance of getting HIV? And if so, what is the optimal dose? “

Mgodi said there are no plans to apply for a license for VRC01. Instead, the proof-of-concept study is used to design future studies evaluating antibodies and antibody combinations for HIV prevention.

Corey noted that the cost of antibodies is gradually decreasing and that treatment with bNAb may be economically feasible in the future.

“HIV is always a huge pathogen – what hopefully happens doesn’t always have to happen,” he said. “We are not disappointed with this study because we got what we really wanted – to have a success marker that leads the field forward and shows that we can demonstrate the proof of concept.”

“Foundation” for future research

In a statement by the National Institute of Allergy and Infectious Diseases Director Anthony S. Fauci, MD, The results “establish the concept that passive administration of a largely neutralizing antibody can prevent the acquisition of susceptible strains of HIV.”

“The lessons learned from the AMP studies form the basis for the future development of long-acting antibody-based HIV prevention tools and ultimately a vaccine,” said Fauci.

As stated on the study website, giving antibody infusions skips the vaccination step and directly gives them the antibodies they may produce after vaccination.

Scientists have long searched for a vaccine against HIV.

According to Pontiano Kaleebu, MD, PhD, Kaleebu, who directs the Uganda Virus Research Institute, has completed more than 250 Phase 1 or Phase 2 HIV vaccine trials and 10 Phase 2b or Phase 3 trials since 1987. Kaleebu recorded a presentation on the subject for journalists covering the conference.

Early last year, Fauci’s NIAID halted a Phase 2b / 3 study, HVTN 702, after an independent data and safety monitoring body found the vaccine was not working – a finding that caused great disappointment in the scientific community.

The study enrolled more than 5,400 participants in 14 locations in South Africa to test a vaccine based on a regimen that, according to a vaccine study published in Thailand in 2009, was around 31% effective in a vaccine study.

Following the cancellation, there were three ongoing studies on the effectiveness of HIV vaccines, including the HVTN 705 Phase 2b study, nicknamed Imbokodo, which is being conducted in five South African countries. and the Phase 3 HVTN-706 study called Mosaico, which is being conducted in eight North American, South American, and European countries including the United States. Both are evaluating investigational vaccines that use “mosaic” immunogens to ensure maximum coverage against circulating HIV strains. Said Kaleebu.

There is also keen interest in using messenger RNA vaccine technology – the same technology used in the two US-approved COVID-19 vaccines – for HIV and other infections, including malaria and tuberculosis, Fauci said.

Moderna, which developed one of the COVID-19 vaccines, has already expanded its mRNA program to develop vaccines against HIV, influenza and the Nipah virus.

“HIV research has absolutely helped COVID-19. Now that we have a successful vaccine with mRNA, it will return, ”Fauci told journalists before the conference. “Everything that goes around comes around. Hopefully we will get more insight into HIV vaccines. “

References:

Mkhize NN et al. Abstract 1188. Presented at: HIV Research for Prevention; 27.-28. January and 3-4. February 2021 (virtual meeting).

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Paul A. Volberding, MD)

Paul A. Volberding, MD

We have known for years that circulating antibodies play a role in HIV control. While this report is not the simple “home run” we once believed in, it offers vital insight into its potential role in preventing HIV infection. We know that HIV mutates in response to immunological pressures as well as the presence of less effective antiretroviral drugs. This study used an antibody chosen for its ability to neutralize a fairly wide range of HIV isolates and infused that into people at risk of HIV infection and tracked participants to see how many HIV infections were acquired. The researchers report that the antibody infusions were very effective (around 75%) when the HIV they were exposed to was sensitive to the antibody in the study. However, the treatment did not prevent infection by HIV variants that were less sensitive to this antibody. While this approach is unlikely to play a common role in population-level HIV prevention strategies, it will nonetheless be very valuable to better design recent efforts to use antibodies or combinations with a broader neutralization and possibly use them as therapeutics in attempts at healing to investigate HIV infection. It’s great to see uses of antibodies in treatment and prevention for both HIV and COVID-19.

Paul A. Volberding, MD

Editor-in-Chief, Infectious Disease News

Professor of Medicine

Director of the AIDS Research Institute

University of California, San Francisco

Disclosure: Volberding reports on advising Gilead and chairing a Merck Data Safety Monitoring Board.

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