Pgt 121 Monoclonal Antibody May Lead to Reduction of Non-HAART Viral Load

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In Search of Cure Viral Load HIV infection What is CD4

Viral Load, why is it so important? Many people seek me, no longer for Whats AppThat's true, because I didn't close myself to the diode. The high viral load "accelerates the tremor down the mountain and the low viral load slows this train down to the fallen bridge at the end of the mountain."

We have downloaded the viral load and kept it low since the end of 1996, beginning of 1997, and from there, nothing has changed. Best Remedies?


More light side effects? (…)

But it all depends, or has depended on antiretroviral therapy and its adherence, when a person living with HIV or “case of AIDS".

Since then, as I said on an ESPM show, little or almost nothing has changed!

The virus can only be controlled with antiretroviral therapy, but that may be to change!


Monoclonal antibody
Kathryn_Stephenson Photo credit is the same as the author of the story

A monoclonal antibody named Monoclonal Antibody PGT 121 viral suppression that lasted up to six months in seropositive individuals started with a low viral load, according to the results of a small study Conference on Retroviruses and Opportunistic Infections (CROI 2019) last month in Seattle.

This is the longest term that someone has kept HIV undetectable after a single infusion of largely neutralizing antibodies. And, initial data suggest that PGT121 Monoclonal Antibody has potential for use as pre-exposure prophylaxis (PrEP), said Dr. Kathryn Stephenson of Beth Israel Deaconess Medical Center in Boston.


Broadly neutralizing antibodies (bNAbs) that act against a wide range of HIV strains are one of many approaches that are being explored in an effort to cure HIV or, most likely, cause long-term remission that will allow people with HIV to maintain viral suppression. daily antiretroviral therapy (ART) throughout life.

Monoclonal Antibodies would hunt for this "entity", HIV
Digital illustration of HIV virus in color background

Although previous studies have shown that the bNAbs have activity against HIV replication, it is less clear that they can attack the virus in latently infected cells, known as viral reservoirs.

Most experts expect a combination of different approaches to achieve a lasting remission or a cure to be needed.

PGN 121 Monoclonal Antibody is a recombinant monoclonal antibody targeting the V3 glycan site in the outer envelope of HIV, SIV (a related virus that infects monkeys) and SHIV (a human-simian hybrid virus) and demonstrated activity against 60% or more of the HIV strains found worldwide.

The PGT121 is being developed by a collaboration that includes the International AIDS Vaccine Initiative, the Bill & Melinda Gates Foundation, the Scripps Institute and the Theraclone Sciences.

Previous studies in rhesus monkeys have shown that Monoclonal PGT 121 could decrease viral load, help slow the viral reaction and protect against SHIV infection, suggesting that it could be used for both treatment and HIV prevention.

At CROI last year, Dr. Dan Barouch, also from Beth Israel, reported that most monkeys who received PGT121 experienced a viral rebound not long after stopping antiretrovirals, but some animals maintained viral suppression longer than expected. Adding GS-9620, a TLR7 agonist that stimulates Toll-like receptors to activate the cells of the immune system, has led to further delay before viral rebound. In fact, five of the eleven monkeys treated with the combination maintained undetectable viral load for at least six months after ART discontinuation.

At this year's conference, Stephenson reported the findings of a 1 phase clinical trial of the PGT 121 Monoclonal Antibody - the first study in humans.

The first part of the study was a dose escalation trial involving 20 HIV-negative volunteers and 15 HIV-positive people in ART suppressor. Participants received 3, 10 or 30 mg / kg PGT121 administered as a single intravenous infusion or 3 mg as a subcutaneous injection. In each group of five people, one person received a placebo.

The second part was an open study of PGT121 using the intravenous dose of 30 mg / kg in 13 HIV-positive people who were not taking ART, of whom nine had high viral load (above about 2000 to 100.000 copies / ml) and four had low viral load (about 200 to 500 copies / ml). Seropositive participants were mostly white males, with a median age of 44 years for those on ART and 31 years for those who did not have ART.


The half-life of Monoclonal PGT 121 (a measure of how long it lasts in the body) was up to 23 days, but lower in HIV-positive people who are not on ART (13 days). The most common side effects were pain, redness and swelling at the injection site, generally classified as mild.

One participant experienced a moderate adverse event that is believed to be related to the drug. There was no evidence that PGT 121 Monoclonal Antibody led to increased cellular immune responses and cell count CD4 remained stable.

Looking at non-HIV positive people five of nine participants in the high viral load group showed evidence of antiviral activity on the 10 day, with a mean viral load decline of 1.7log10 (about 60 copies / ml); four were considered non-responders.

Although HIV was sensitive early in the study, on day 21-28 all five had viral repercussions and resistant viruses were found.

In the low HIV-positive viral load group, viral levels fell below the level of quantification in two participants on day 7.

They maintained prolonged viral suppression ART, which in one case lasted more than five months and the other was still in progress six months. In these participants, viral remission continued after PGN 121 antibodies dropped to a low or undetectable level, suggesting long-term activity. The follow-up continues to see how long this remission will last.

“Long-term virological suppression is probably due to the excellent potency of the PGT 121 Monoclonal, even at levels below the limit of quantification.”, the researchers concluded.

Stephenson suggested that PGN 121 would probably have to be combined with different antibodies or other agents in people with higher viral loads. She also suggested that Monoclonal Antibody PGT 121 could have potential as PrEP long-lasting.

Translated and republished in Portuguese by Cláudio Souza do origial in Monoclonal antibody may lead to long-term viral load reduction Posted: 11 April 2019 DO NOT Aidsmap


Stephenson KE et al. Therapeutic activity of PGT121 monoclonal antibody in HIV infected adults. Conference on Retroviruses and Opportunistic Infections, Seattle, abstract 145, 2019.

I myself do not like PreP within the context in which they are inserted

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