It was going to be a quick trip to the supermarket. I didn’t even want to go in the first place but I had visitors from Cape Town and they wanted breakfast. Luckily it was early and I got parking right by the entrance of the mall. I zipped through the aisles grabbing the necessary and as I swept a two-litre bottle of milk off the shelf an Adonis checking out the nutritional info on the side of a milk carton stopped me in my tracks.
Today, HIV infections are completely treatable thanks to antiretroviral medication. Only problem is these drugs must be taken on a regular basis for them to remain effective, and for many HIV-positive individuals throughout the world, this simply isn’t possible. A new antiretroviral drug called cabotegravir, however, may solve this widespread problem, since it only requires injection once every three months.
HIV, like all viruses, thrives by replicating itself, thus turning our body’s cells into little HIV-making factories. Antiretrovirals interfere with HIV’s ability to replicate. The drugs are used not only on HIV patients to keep the virus at bay, but also as a preventive measure on individuals who are at an increased chance of catching the virus. There are currently more than 20 approved antiretroviral drugs approved for use in the U.S. and Europe, and once a patient starts an antiretroviral regimen, it's best he adheres to it. Unfortunately, this is difficult for many, but researchers believe that cabotegravir may change this.
According to a recent study, cabotegravir targets the enzyme the HIV virus uses to integrate itself into the cell’s genome. As reported in the press release, it is chemically similar to the already used integrase inhibitor dolutegravir, but with the added bonus of working for months before needing to be replenished.
"Long-acting cabotegravir has the potential to create an option that could improve adherence by making it possible to receive the drug by injection once every three months," Dr. Martin Markowitz, a professor at Rockefeller University and ADARC and researcher on the study, explained in the press release.
At the moment, a phase 2 trial on low-risk humans is underway. Once this is completed and proved to be effective, the drug will be tested on more high-risk human subjects.
While treating HIV is a high priority for the development of cabotegravir, the team’s main objective is to offer protection against the virus for individuals who are at increased risk. Tests have shown that cabotegravir injections were 90 percent effective in protecting monkeys from the vaginal transmission of a virus similar to HIV even after repeated high-dose exposures.
"While we are still a long way off from showing that this drug works for HIV prevention in humans, our hope is that it may one day offer high risk women, as well as men, an additional option for HIV prevention," Markowitz said.
Source: Andrews CD, Yueh YL, Spreen WR, et al. A long-acting integrase inhibitor protects female macaques from repeated high-dose intravaginal SHIV challenge. Science. 2015.