Long-Acting, Multi-Drug HIV Implant Shows Promise

People who currently have to take daily pills for HIV prevention or treatment may have access to a more convenient alternative in the near future, going by a recently-reported study by researchers at the University of North Carolina (UNC).

Images of HIV Implant (UNC School of Medicine)

Findings from a seven-year, animal study suggests that an injectable, multi-drug implant developed by researchers can make it easier to both treat and prevent HIV. This promising alternative can reportedly help to control the viral infection for up to a year.

The injectable implant features a polymer, an organic solvent, and HIV-fighting drug(s). A combination of these elements results in a liquid solution that resembles honey.

The formulation becomes solid in the body when injected. Thus enabling it to remain there for a longer time while exerting the desired effect.

“To have an HIV prevention treatment that consists of an injection once or twice a year would make an incredible impact for patients,” said study first author Rahima Benhabbour, assistant professor in the UNC NCSU Joint Department of Biomedical Engineering. “This technology is not only promising for HIV but for any kind of condition that requires a daily intake of medication.”

This new study carried out by a team of researchers from different departments at the UNC, appeared in the journal Nature.

Challenges of combating HIV

To treat and prevent the immunodeficiency caused by HIV, people usually rely on antiretroviral drugs. These medications must be taken every day and in combination to guard against drug resistance.

Many patients, however, find it difficult keeping to the daily pill regimen. This happens for reasons beyond their control in some cases.

Benhabbour noted that many people who need these pills in sub-Saharan Africa, which has the highest HIV cases, lack access. The stigma of being seen as having HIV further discourages those trying to protect themselves against the virus from going all out to get the drugs.

There are also cases where people who take antiretroviral drugs may miss taking them or do so at a less-ideal time. This can adversely impact their efficacy.

These challenges make the new long-acting drug delivery system developed by UNC researchers all the more interesting.

Long-acting and more Convenient Treatment

The injectable implant developed in this new research changes in consistency when injected under the skin. It assumes a solid form, thus eliminating the need to have it injected every day.

The organic solvent in the formulation diffuses into a user’s body after injection. The combination of the polymer and drugs determines the length of time the medications will remain in the body.

“Because one of the biggest difficulties associated with HIV prevention is lack of adherence to drug treatment, we wanted to create a drug delivery system that solved this problem,” said senior study author J. Victor Garcia, professor of medicine at UNC School of Medicine.

The researchers tested six antiretroviral medications in the study. These retained their physical and chemical properties both as part of the formulation and upon release. The drugs were released at consistently effective levels for a period of one month to a year.

The First of its kind

Benhabbour said researchers in the current study were the first to use this multi-drug delivery system.

There is currently no long-acting HIV prevention technology approved by the FDA. The new injectable seeks to address a major concern about similar systems, which is how to get rid of it along with any residual drug(s).

The long-acting implant is biodegradable. After some time, it turns into lactic and glycolic acids. The body can easily absorb these acids.

If the patient wishes to stop treatment for one reason or another, the implant can be surgically removed effortlessly. It is the first of its kind that can be removed in as little time as one week.

There are plans to continue with further development and fine-tuning of the delivery system. More in-vivo studies are to be done before it can be evaluated in humans.