Scientists Say Claims of HIV Cure "Within Months" Misleading

It has been nearly half a year since news sources inaccurately reported that Danish scientists were "within months" of finding a cure for HIV for their ongoing, and as-yet-unpublished, research of histone deacetylase (HDAC) inhibitors. Although a cure is not on the immediate horizon, the Danish vaccine trial continues to look at HDAC inhibitors -- and even a cancer drug -- as a means to flush HIV from the viral reservoir, where it hides from antiretrovirals even during successful therapy.

"I am almost certain that we will be successful in releasing the reservoirs of HIV," said Dr. Ole S�gaard, a senior researcher at the Aarhus University Hospital in Denmark, who is leading the study. "The challenge will be getting the patients' immune system to recognize the virus and destroy it. This depends on the strength and sensitivity of individual immune systems."

With antiretroviral drugs, people can live a long life with HIV. But if medications are stopped, HIV reservoirs become active and start to produce the virus. Doctors are now trying to find ways to destroy the HIV virus that is hiding in this reservoir.

In their attempt at a cure, the Danish researchers and other non-Danish collaborators are in the middle of a Phase I human trial involving 15 participants. S�gaard warned that a cure was not the same as a preventative vaccine, and noted the importance of continuing education of safer sex and injection drug use risks.

But researchers are still doing damage control from an inaccurate April 17 article from the U.K.'s The Telegraph that read, "Scientists on the brink of HIV cure." The article goes on to qualify this statement through a quote from S�gaard, who said that he felt confident about HDAC inhibitors' abilities to activate HIV from the reservoir, but that questions remain about the body's ability to kill flushed virus.

The clinical trials are testing a "novel strategy" in which the HIV virus is stripped from human DNA and destroyed permanently by the immune system. After discovering that the strategy works in laboratory tests, the Danish Research Council awarded the team 12 million Danish kroner to pursue their findings. Scientists are conducting human trials using their treatment, in the hope of proving that it is effective.

The technique involves releasing the HIV virus from "reservoirs" it forms in DNA cells, and bringing it to the surface of the cells. Once it comes to the surface, the body's natural immune being boosted by a vaccine.

S�gaard's confidence about HDAC inhibitors' abilities to active HIV from the reservoir may have prompted the Telegraph's inaccurate story. But numerous news outlets ran with the story, some touting claims that scientists were "within months" of a find a cure for HIV.

The researchers were quick to correct the misconception, with S�gaard calling his team's work "a very interesting trial, which I hope will help inform HIV researchers how to get closer to a cure for HIV. The trial is still ongoing."

As the story ignited hope across the world, other scientists were quick to correct the misconception. Dr. Dennis Sifrisvand and Dr. James Myhre told The Inquisitr said that while Danish scientists made "a good first step," a cure could be a bit further off. They note that the human trials could take "on average 5-8 years from the start of research to final FDA approval. And that's if nothing goes wrong."

S�gaard said in an email to POZ, "No, I would not say that we are on the brink of an HIV cure, and I can say for sure that I never said that we were. It would have been great if the story had been angled in a less sensational way." Regardless, S�gaard and his team of Danish researchers continue to look for new ways to drive HIV out of the viral reservoir.

Danish Scientists Use Cancer Drug to Drive HIV Out of Hiding

In their attempt to target the viral reservoir, Danish scientists have been looking at potential ways of curing HIV infection with the experimental cancer drug panobinostat. Interim results of their clinical trial were presented in June at the [International AIDS Society] pre-symposium meeting in Kuala Lumpur, Malaysia, in late June.

"The journey toward a cure will not be easy and many challenges lie ahead. Some of the challenges are known, others may only become known as experiments proceed," said Sean R. Hosein in CATIE, Canada's source for HIV and hepatitis C information. "As with any great scientific endeavor, there will be setbacks. The initial wave of cure research experiments over the next five to 10 years should be viewed as exploratory and their results highly preliminary. This research will seek to answer important scientific questions that can then be used to build a foundation toward a cure."

In collaboration with other scientists in Australia, Sweden and the United States, they are testing a drug that will hopefully help to drive HIV out of hiding. This approach has the potential to reduce the burden of HIV-infected cells in the body and make future attempts at a cure perhaps easier. The drug being tested is an experimental cancer therapy called panobinostat, made by the pharmaceutical company Novartis. Panobinostat belongs to a class of drugs called HDAC inhibitors.

Several years ago, a team of researchers at Aarhus University in Denmark conducted a randomized, placebo-controlled study to compare the effect of a pneumonia vaccine with or without CpG 7909 in 97 HIV-positive people who were taking combination anti-HIV therapy (commonly called ART or HAART). In this study, repeated injections of 1 mg of CpG 7909 at the start and in the third and ninth months of the trial significantly increased the immune response to the vaccine.

But the Danish team did some additional research. After the study was completed they reanalyzed stored blood samples from a subset of participants. The purpose of this reanalysis was to assess the impact that exposure to CpG 7909 may have had on the proportion of HIV-infected cells in the blood.

The team found that the proportion of HIV-infected cells fell by 12 percent after each injection of CpG. This finding suggests that regular exposure to CpG 7909 can reduce the burden of HIV-infected cells in the body. This burden is called the "reservoir" by scientists and, in theory, a smaller reservoir should make curing HIV ultimately easier over the long term. But separate clinical trials will be needed to assess this possibility, as none of the participants who received CpG injections were cured.

In contrast, among participants who received placebo, the proportion of HIV-infected cells remained about the same. Furthermore, participants who received injections of CpG appeared to have killer T-cells (called CD8+ cells) with increased anti-HIV activity. There was no detectable increase in HIV antibodies in participants.

According to the researchers, CpG 7909 was "generally well tolerated," with mild side effects at the injection site. In some cases there were also temporary flu-like symptoms and in 76 percent of participants, these were judged to be of "moderate to severe" intensity. Exposure to CpG did not reduce CD4+ cell counts.

In some cases, there were very small and temporary increases in HIV viral load. But no participant had their viral load become detectable (that is, rise above the 50 copies/ml mark) for more than two consecutive blood tests. Further analyses found that CpG 7909 did not cause any toxicity to major organ-systems such as the bone marrow, liver or kidneys.

"What is clear is that no one has yet been cured of HIV by repeated exposure to CpG 7909 over a period of 10 months," reported Hosein. "Also, such a cure -- with this or any other therapy -- is not imminent. Rather, much more study is required of this exciting compound, perhaps in combination with other experimental drugs in HIV-positive people who are taking ART."