Scientists Have Submitted A New Drug To Treat HIV

Scientists Have Submitted A New Drug To Treat HIV.
Scientists are reporting beforehand but heartening results from a new drug that blocks HIV as it attempts to invade hominid cells. The approach differs from most current antiretroviral therapy, which tries to confine the virus only after it has gained entry to cells. The medication, called VIR-576 for now, is still in the cock's-crow phases of development.

But researchers say that if it is successful, it might also circumvent the drug resistance that can drain standard therapy, according to a report published Dec 22 2010 in Science Translational Medicine. The novel approach is an attractive one for a number of reasons, said Dr Michael Horberg, kingpin of HIV/AIDS for Kaiser Permanente in Santa Clara, California. "Theoretically it should have fewer secondary effects and indeed had minimal adverse events in this study and there's probably less of a chance of evolution in developing resistance to medication," said Horberg, who was not involved in the study.

Viruses replicate inside cells and scientists have large known that this is when they tend to mutate - potentially developing new ways to stem drugs. "It's generally accepted that it's harder for a virus to mutate outdoor cell walls".

The new drug focuses on HIV at this pre-invasion stage. "VIR-576 targets a duty of the virus that is different from that targeted by all other HIV-1 inhibitors," explained study co-author Frank Kirchhoff, a professor at the Institute of Molecular Virology, University Hospital of Ulm in Ulm, Germany, who, along with several other researchers, holds a blatant on the young medication. The target is the gp41 fusion peptide of HIV, the "sticky" end of the virus's outer membrane, which "shoots be fond of a 'harpoon'" into the body's cells, the authors said.

The originate of this peptide is a first step in the virus's bid to reside in host cells. Although there are two other drugs on the market, maraviroc and T-20, which also prevent the virus from entering cells, they don't butt fusion peptides. That makes this trial the essential time that scientists have seen that fusion peptides are a worthwhile target in the fight against HIV/AIDS.

And given that fusion peptides also outfit a point of entry for many other viruses, from measles to Ebola and hepatitis B and C, scientists guess that the strategy could be turned against these illnesses as well. The 18 patients with HIV in this tight phase I/II trial took either 0,5 or 1,5 or 5 grams of VIR-576 a time for 10 days via injection. Those taking the highest dose saw a 95 percent reduction in their commonplace viral load, the amount of HIV in the blood, without developing severe adverse effects.

And "They were getting results that are comparable to maraviroc and T-20 and certainly comparable to what's seen with intracellular drugs". But the same factors that have restricted the use of maraviroc and T-20 are also likely to get in the way here as well, specifically the cost and the fact that they must be given by injection (because of the large size of the molecule), he warned.

The needle-vs-pill snag is something patients and doctors have to contend with in many settings, not just HIV. For example, "we all certain that insulin works great in diabetic patients but the hard part is convincing patients to actually turn to it". Hoping to get around the problem, the researchers are now searching for a smaller molecule to do the same job.

So "The next big out of step is to use the structure of VIR-576 and its viral target (the fusion peptide) to generate small molecule inhibitors that feigning by the same mechanism but are orally available. We will start to test the first compounds next year, but how elongate it will take such drugs make it to the market is impossible to say. The bottom pitch is, yes, any time that you can find a new mechanism to attack the virus - and certainly if you can inhibit the virus from getting into the host cells - that's a really good thing neuchtel. But this isn't near prime-time," Horberg concluded.