Since the early 2000s, the advent of powerful new anti-retroviral medicines has greatly reduced mortality among people infected with HIV. Cocktails of these medicines can, in fact, essentially cause the virus to go into hibernation if taken on a regular basis, allowing patients to live otherwise normal lives.
Source: Gilead Sciences,
Efforts to cure infected patients, however, have largely failed, despite some high-profile success stories such as the so-called "Berlin cancer patient".
Numerous attempts to replicate these unexpected and surprising results have proven utterly unsuccessful. The biggest holdup for a functional cure for HIV is something known as "viral reservoir" problem.
In a nutshell, some cells carry the virus but can remain hidden because they rarely express any viral gene products. When a patient undergoes pharmaceutical intervention, these cells are believed able to reinfect patients post-treatment.
Given the tricky problem viral reservoirs present, researchers are trying to figure out a way to get latent HIV-carrying cells to express proviral DNA, allowing them to be targeted by pharmaceutical compounds. This strategy is known as "Kick and Kill" or "Shock and Kill."
The nature of the viral reservoir problem is multifactorial in nature, meaning few compounds are believed to be potent enough to cause all latent virus-containing cells to be activated simultaneously.
Source: Gilead Sciences.
A game changer in the fight against HIV?
Gilead Sciences (NASDAQ: GILD) might have hit upon a compound, by accident, that appears potent enough to do the trick. GS-9620 is an oral toll-like receptor-7 agonist being studied as a treatment for chronic hepatitis B infections.
However, the compound's unique ability to activate multiple aspects of the immune system (B and T cells, for example) got the biotech thinking about how it could be applied toward the viral reservoir problem in HIV.
In two preclinical studies using human cells and nonhuman primates, Gilead found that GS-9620 significantly increased the amount of detectable virus, meaning it appears to have the ability to activate latent carriers of the disease.
But the really exciting finding was that viral load also dropped, presumably because of the therapeutic action of the various anti-retroviral drugs being administered along with GS-9620.
Source: Wikimedia.
Going forward, the hope is that GS-9620 can essentially "shock" a person's cells into expressing the virus, allowing a cocktail of antiviral drugs to eradicate the virus from the system. If this strategy works, it would be the first functional cure of HIV.
What's next?
Gilead found the preclinical data promising enough to begin a small safety and proof-of-concept trial in humans. Given that infectious disease studies such as this one are fairly quick by clinical trial standards, the top-line results could be released before year's end.
While there is no guarantee that this exploratory study will be successful, keep in mind that Gilead has a knack for hitting on revolutionary new treatments in the area of infectious diseases.
Its various combo HIV pills have become the standard of care throughout much of the world. And the biotech recently brought us one of the most effective treatments for nearly all forms of hepatitis C (Sovaldi). So if Gilead were to develop a functional cure for HIV, I personally wouldn't be surprised.
All told, this potential HIV cure is yet another reason to dig deeper into Gilead Sciences' amazing pipeline, which I believe is woefully underappreciated on Wall Street.
