Subdermal Implant Delivers Potent HIV Therapy

Implant delivers sustained release of ARV drugs up to 40 days with no adverse side effects.

A new approach to drug delivery may offer a promising future for HIV therapy.

A study published in Antimicrobial Agents and Chemotherapy analyzed the use of a novel subdermal implant to deliver potent antiretroviral (ARV) drugs in dogs. The matchstick size implant can deliver a controlled, sustained release of ARV drugs for up to 40 days with no adverse events.

"To our knowledge this is the first implant to be used for this purpose," Oak Crest Institute of Science President and founder Marc Baum said in a press release.

The daily administration of oral or topical ARV drugs to uninfected individuals in vulnerable populations offers a promising preventative strategy for HIV, but medication adherence remains a critical hurdle in determining whether this approach is effective.

"This novel device will revolutionize how we treat or prevent HIV/AIDS as it delivers powerful HIV-stopping drugs and eliminates one of the key obstacles in HIV/AIDS prevention -- adherence to proper dosing regimens," Dr. Baum said.

Adherence remains a significant issue in the treatment of HIV, which prompted the need for new treatment strategies.

"It's unfortunate, but patients do not always follow the dosing instructions as prescribed," Dr. Baum said. "In clinical trials erratic administration of drugs has led to highly variable efficacy outcomes. That's what peaked our interest in the possible use of a subdermal implant for the prevention of HIV.”

The subdermal implant is a small flexible tube approximately 40mm in length that is inserted under the skin by a health care professional. Following insertion, the device prevents pregnancy by releasing hormones that stop ovaries from releasing eggs and through thickening cervical mucous.

"Our subdermal implant is used in the same manner as a contraceptive implant,” Dr. Baum added. “It is easily inserted and removed and provides sustained release of the potent prodrug tenofovir alafenamide, which is roughly 10 times more potent against HIV than tenofovir disoproxil fumarate, another tenofovir prodrug that has been shown to prevent sexually transmitted HIV when used as a pre-exposure prophylaxis. We are very pleased with the results of our preliminary studies and are working diligently to develop a subdermal implant for HIV prevention that will remain effective for a full 12 months."