Triple therapy clears HIV in newborn primates, suggesting path to cure

Researchers at Oregon Health & Science University have shown that a three-drug regimen given to newborn primates within 72 hours of HIV exposure can permanently clear the infection. The study, published in Nature Microbiology, tested a combination of standard antiretroviral therapy, broadly neutralizing antibodies, and the experimental monoclonal antibody leronlimab, which blocks the CCR5 receptor that HIV uses to enter immune cells.

Each of the three treatments had previously failed to eradicate the virus when used alone. The research team, led by Jonah Sacha and Nancy Haigwood, said they were surprised that the combination succeeded in eliminating detectable virus and preventing the establishment of a long-term viral reservoir in the infant macaque model.

Antiretroviral therapy suppresses viral replication, broadly neutralizing antibodies reduce circulating virus, and leronlimab blocks residual virus from infecting new cells. Haigwood described the interaction as a dynamic process during the first week of infection that appears more complex than previously understood.

All three components have either been approved for human use or are already in separate clinical trials, which the authors say could accelerate testing of the combined regimen in people. The researchers plan to evaluate the therapy first in newly exposed adults before moving to newborns.

The study only tested treatment initiated within three days of exposure. Sacha said it remains unknown whether the regimen would work if started a week or two weeks after infection, and further experiments are needed to define the therapeutic window.

More than 120,000 newborns acquire HIV globally each year, and the virus continues to kill approximately 600,000 people annually. A short-course curative regimen could reduce the need for lifelong treatment, though clinical trials are required to confirm safety and efficacy in humans.