SUPPRESSING THE VIRUS

New therapy keeps HIV at bay without daily drug regimen.

BY VICTOR MELAMED

The hunt for an HIV treatment that roots the virus out of its hiding places and kills it just got more interesting, reports the LA Times.

A human antibody that already has shown promise in protecting people against HIV infection has demonstrated the ability to suppress the resurgence of the infection for as long as 19 weeks in infected people who stopped taking their anti-retroviral medications.

Infusions of a neutralizing antibody called 3BNC117 staved off the human immunodeficiency virus for more than a month.”

In a letter published in the journal Nature, scientists report that in 13 HIV-infected people who discontinued their cocktail of retroviral drugs, infusions of a neutralizing antibody called 3BNC117 staved off the expected rebound of the human immunodeficiency virus for more than a month.

Typically, when an HIV-infected patient stops taking his or her anti-retroviral medications, the virus bounces back to dangerous levels within 18 days, reports the LA Times. But in findings reported last month, scientists wrote that all of the 13 participants saw their viral loads suppressed to very low levels for at least five weeks after their last treatment—delaying resurgence of the virus twice as long as normal.

Six of the 13 participants saw their viral loads suppressed to very low levels for at least nine weeks after their last treatment—three times the normal span.

The new finding emerged from a clinical trial designed to assess the safety of an experimental therapy that aims to harness the immune system to battle HIV infection. Trial participants who discontinued their anti-retroviral medications were monitored closely and returned to their drug regimen as soon as the rebound of the virus was detected.

None of the patients experienced acute retroviral syndrome—a powerful resurgence of the virus that makes it harder to regain control of HIV following a medication lapse. And genetic sequencing of eight participants’ rebounding viruses suggested that the antibody infusions had not, in most cases, flushed different or more-resistant strains of HIV from their hiding places.

In fact, reports the LA Times, the authors of the new report said, the antibody therapy “appears to restrict the outgrowth of viral genotypes from the latent reservoir.”

The experimental therapy is part of a broad effort to find new ways to control HIV infection, and possibly to drive it out altogether.