Weekly HIV Treatment Is on The Horizon

Changes abound for HIV treatment options around the world. With the approval of a 2-drug regimen, and studies showing that 4-day antiretroviral therapy (ART) regimens are just as effective as 7-day regimens, patients living with HIV will soon be able to leave behind the mountains of pills they are required to consume every day. Indeed, investigators from the Massachusetts Institute of Technology (MIT), Brigham and Women's Hospital (BWH), and Lyndra, have developed a drug capsule that could drastically pare down ART to an easier-to-adhere-to weekly regimen.

When the Centers for Disease Control and Prevention (CDC) released its “Dear Colleague” letter in September 2017, stating that, “when ART results in viral suppression, defined as less than 200 copies/ml or undetectable levels, it prevents sexual HIV transmission,” it spurred the launch of the “Undetectable=Untransmissable” campaign, which champions adherence to an appropriate ART regimen to hit and maintain viral suppression to stop the spread of the disease to others. Help for adherence may soon come in the form a weekly drug delivery capsule.

According to a press release on the MITBWH research, “The new capsule is designed so that patients can take it just once a week, and the drug will release gradually throughout the week. This type of delivery system could not only improve patients' adherence to their treatment schedule but also be used by people at risk of HIV exposure to help prevent them from becoming infected.”

The invention has been dubbed a “pillbox in a capsule.” Originally developed in 2016, the device “consists of a star-shaped structure with 6 arms that can be loaded with drugs, folded inward, and encased in a smooth coating. After the capsule is swallowed, the arms unfold and gradually release their cargo,” according to the press release. A previous study of the capsule using the malaria drug ivermectin proved that it could remain in the stomach up to 2 weeks, gradually releasing the drug during this time. Armed with this knowledge, the researchers set their sights on adapting the capsule to be able to deliver HIV medications.

They found that they could enable each of the 6 arms of the capsule to be able to be filled with “a different drug-loaded polymer, [making] it easier to design a capsule that releases drugs at different rates,” according to the release. Tests on pigs revealed that the capsule could stay in the stomach and release 3 different HIV drugs over the course of 1 week. Once all the drug is released, the capsule then disintegrates into smaller components that pass through the digestive tract.

The investigators took their research a step further to determine the potential impact the capsule could have on preventing HIV infections once it is implemented. According to the release, “Working with the Institute for Disease Modeling in Bellevue, Washington, [the investigators] calculated that going from a daily dose to a weekly dose could improve the efficacy of HIV preventative treatment by approximately 20%. When this figure was incorporated into a computer model of HIV transmission in South Africa, the model showed that 200,000 to 800,000 new infections could be prevented over the next 20 years.”

Speaking on the ramifications of this research in the release, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Disease, which partly funded the research is quoted as saying, “Substantial progress has been made to advance ART, enabling a person living with HIV to achieve a nearly normal lifespan and reducing the risk of acquiring HIV. However, lack of adherence to once-daily therapeutics for infected individuals and pre-exposure prophylaxis for uninfected at-risk people remain a key challenge. New and improved tools for HIV treatment and prevention, along with wider implementation of novel and existing approaches, are needed to end the HIV pandemic as we know it. Studies such as this help us move closer to achieving this goal.”