May 6, 2013
Danish researchers have begun testing panobinostat, an HDAC inhibitor, in 15 patients, in an attempt to find an HIV cure. HDAC inhibitors, which are traditionally used to treat cancer, are now being studied for their potential to flush HIV out of the latent reservoir.
The current phase of the study is set to be completed in September, but the researchers, led by Ole Sogaard, M.D., hope to have initial results within a few months.
"I am almost certain that we will be successful in activating HIV from the reservoirs," [Sogaard] said.
"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, as well as how large a proportion of the hidden HIV is unmasked."
[...] Dr Sogaard stressed that a cure is not the same as a preventative vaccine, and that raising awareness of unsafe behavior, including unprotected sex and sharing needles, remains of paramount importance in combating HIV.
However, the original Telegraph piece may have been overly optimistic when it reported that the researchers were on the brink of a cure, as David Evans of Project Inform explained:
Last week the London Daily Telegraph ran a story on this new compound, but claimed that a cure was just around the corner. The reporter apparently misquoted the researcher and overly hyped what he'd been told. The reporter has since toned down his piece and changed the headline due to pressure from a prominent activist in England and likely due in part to a piece the researchers themselves felt compelled to post to refute the article's claims. Unfortunately, the press outside of London grabbed hold and has been retreading the original uncorrected story since then.
While this is another promising study that should yield informative results, expectations should be tempered. We've heard about HDAC inhibitors before, particularly studies testing vorinostat, which Joseph Eron, M.D., talked about during his HIV cure overview presentation at ID Week 2012. In a small pilot study following eight patients, vorinostat was able to get latently infected cells to express HIV. However, as Eron noted, "We didn't show that you could actually reduce the reservoir. We didn't show that these cells died. We did show that there were no adverse events, which was good, but these were only single doses." Still, Eron said, this study marked the first successful in vivo demonstration of an HDAC inhibitor disrupting latency.
Then earlier this March at CROI 2013, Sharon Lewin, M.D., presented her findings testing multiple doses of vorinistat in 20 patients. The results were similar to the pilot study, in that vorinostat was able to awaken the reservoir but did not reduce its size. Lewin noted that the results indicated that future studies needed to include additional strategies.
Warren Tong is the research editor for TheBody.com and TheBodyPRO.com.
Follow Warren on Twitter: @WarrenAtTheBody.
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