A One-Time Triple Regimen Just Cleared HIV in Newborn Primates

More than 120,000 babies are born with HIV every year. New research from Oregon Health & Science University shows that a short course of three existing therapies — antiretrovirals, neutralizing antibodies, and the experimental drug leronlimab — permanently cleared the virus in newborn macaques when started within three days of birth. Each treatment had failed alone; together, they worked. Published in Nature Microbiology, the finding could move rapidly toward clinical trials.

Key Takeaways

More than 120,000 babies are born with HIV every year.
New research from Oregon Health & Science University shows that a short course of three existing therapies — antiretrovirals, neutralizing antibodies, and the experimental drug leronlimab — permanently cleared the virus in newborn macaques when started within three days of birth.
Each treatment had failed alone; together, they worked.
Published in Nature Microbiology, the finding could move rapidly toward clinical trials.

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Every year, more than 120,000 newborns around the world contract HIV — a diagnosis that normally means lifelong antiretroviral treatment, for those who can access and afford it. A team led by Oregon Health & Science University now reports a striking alternative: a single short course of three therapies, started within three days of birth, permanently cleared the virus in infant macaques.

The research, published in Nature Microbiology on August 10, combined three distinct treatments given for a few weeks: broadly neutralizing antibodies, standard antiretroviral therapy, and leronlimab, an experimental monoclonal antibody that blocks HIV from entering immune cells through the CCR5 surface protein.

Each of the three had previously failed to clear the virus on its own — which is why co-lead author Jonah Sacha said he wasn't convinced combining them would help. His longtime colleague Nancy Haigwood believed the combination was worth testing. "We were astounded and overjoyed, actually," Haigwood said. "It's a remarkable result."

The team likens the triple approach to three layers of defense: antiretrovirals turn off the faucet by minimizing viral replication, antibodies mop up virus circulating in the blood, and leronlimab seals off the route into immune cells — "like you've kept fuel away from the fire," as Sacha puts it.

Exactly why the combination works remains unclear, but researchers suspect the first week of infection is a far more dynamic window than previously appreciated. The next question is how wide that window is: the team only tested the regimen out to three days. Could it still purge the virus a week — or two — after infection?

"There was no reason to think this would completely clear the virus," Sacha said. "It's one of those things where you test it and, holy cow, it works and you've discovered something new."

Because antiretrovirals are already approved in humans and both antibodies and leronlimab are already in separate clinical trials, the researchers say the triple regimen could advance to human trials quickly — most likely first in newly exposed adults. HIV still kills roughly 600,000 people a year worldwide.