Achilles heels found for promising HIV prophylaxis

Injectables, which were praised for preventing HIV a year ago, do not seem perfect today in the light of new analysis.

Researchers examined blood samples collected during the study, revisited 4,570 clinical trials of the drug, and four people who were infected with HIV despite receiving an injection of a drug called cabotegravir are usually infected. I found that I had been infected for more than a month before my HIV test. I detected a virus. During this time, they developed resistance to cabotegravir and closely related treatments used to treat HIV infection. Alternatives to these common medications can treat HIV infections, but they can be expensive or difficult to obtain in some countries.

The team believes that Cabotegravir has adequately suppressed the virus, preventing HIV testing from detecting the virus in the early stages of infection.

The news comes just as some other powerful drugs that prevent HIV are in clinical trials. Raphael Landovitz, an HIV prevention researcher at the University of California, Los Angeles, who presented the results of Cabotegravir at a conference on retroviruses and opportunistic infections on March 9, said scientists leading these studies were more sensitive tests than usual. Suggests that participants need to be monitored. Avoid similar situations.

Still, this type of HIV prophylaxis, called pre-exposure prophylaxis (PrEP) by Landovitz and other scientists, is one of the most promising tools for controlling the virus, which infects about 1.7 million additional people each year. It states that it is one. It is available. Despite the news, PrEP remains a powerful tool, said Quarraisha Abdool Karim, an HIV researcher at the Durban-based South African AIDS Research Program Center. He is not involved in the exam, but is part of network development. These treatments. “When people are using PrEP, they may need to enhance the game with the tests they use,” she adds, adding that this is even more costly.

Improved compliance

2012, US Food and Drug Administration Gave green light Daily tablets of an HIV drug called Tolbada, manufactured by Gilead Sciences in Foster City, California, have proven to be more than 85% effective when taken on schedule. But soon after, studies showed that most people who weren’t infected with HIV didn’t take protective medications daily. For example, clinical trials in Kenya, Tanzania, and South Africa were stopped early because the pill was not functioning.Drug level analysis revealed that many women are not taking them¹..

That’s why researchers have developed longer-lasting treatments like Cabotegravir Shot. The drug stays in the human system for weeks or months, thus requiring less dose, and hopes for improved compliance.I was excited last year When Landovitz reports Bimonthly shots of Cabotegravir have been shown in clinical trials to be three times more effective than daily tolvadapills. The study directly compared drugs between men and transgender women who had sex with men in seven countries, including the United States, South Africa, and Brazil. The trial was so successful with Cabotegravir that an independent oversight committee recommended “blinding” and participants knew if they were receiving torbada and placebo injections or Cabotegravir and placebo tablets, and more. I was able to switch to an effective drug.

However, the research team wanted to better understand why some people were still infected. Researchers have found that some did not stick to the daily tolbada regimen, while others picked up the virus after treatment was stopped.

However, researchers were surprised when they analyzed blood samples of four people infected while taking Cabotegravir. A sensitive test measuring RNA from HIV revealed that participants had been infected for 6 to 16 weeks before the infection was detected by regular monthly HIV diagnosis. Landovitz suggests that cabotegravir is so powerful that it keeps these individuals’ virus levels too low to be detected by standardized tests. However, when the virus evolved resistance to the drug and replicated, it changed and its levels soared.

“The message of take-out here is that we need a better diagnosis, and as soon as we diagnose the infection, we need to be ready to put people in suppressive treatment,” says Landovitz. He states that participants responded well to HIV therapy, which is an alternative to Cabotegravir and such drugs.

Possibility of backlash

Michael Robertson, executive director of Merck Research Laboratories in Boston, Massachusetts, said scientists will evaluate signs of resistance in blood samples in two recent clinical trials launched by Merck to test long-acting PrEP treatment. It states that. One study tests how well the monthly pill of islatravir, a new HIV drug, can prevent HIV. The other is to examine the performance of islatravir-filled matchstick-sized implants (embedded in the human upper arm). He says he remains enthusiastic about treatment despite the consequences of cabotegravir and that monthly pills or implants may appeal to people who are stigmatized for taking daily medications to prevent HIV. I did.

Landovitz agrees. “I remember taking a step back and seeing amazing results,” he says. “This may be unbelievable, so think about ways to minimize the risk to an individual.”

However, some communities that these researchers are struggling to reach due to high HIV prevalence are not so optimistic about the news. Levi Maxwell, a black transgender community activist in San Francisco, warns that news about Cabotegraville could cause a backlash. “The answer is not to tell people that this is better than nothing,” they say. Maxwell explains that many blacks and transgender people are wary of government officials and scientists because of their history of harm and discrimination. Therefore, the negative (albeit rare) effects of taking medications to superficially prevent HIV may appear to support and exacerbate existing distrust of health care providers.

Maxwell recommends that HIV scientists focus on developing new forms of PrEP that do not cause drug resistance. And they suggest that HIV prevention researchers are pushing for policy changes to improve conditions that put blacks and transgender people at risk of HIV transmission in the first place, such as affordable housing and mass imprisonment. There is. “Scientists may have good intentions, but if you want to reach your goals, you need to understand that you don’t have tunnel vision,” says Maxwell. “This is not just a medical problem.”