Evaluating Microarray Patches for Long-Acting PrEP and Contraceptives

Microarray patches (MAPs) are an alternative option for intradermal delivery of vaccines and pharmaceuticals that are in clinical development. MAPs are applied to the skin like a bandage and consist of an array of micron-scale projections (< 1 mm in height) that are amassed on a baseplate.

As bringing long-acting injectables to the continuum of care for HIV is becoming more realistic, investigators are looking to develop a MAP, also known as a microneedle patch, for delivery. MAPs could be key to providing a self-delivery system that is also discreet, which could administer HIV prevention and contraception to women in low-resource settings.

At IDWeek 2019, a team of investigators from PATH presented their research on the development of a MAP to deliver long-acting cabotegravir (CAB LA) for HIV pre-exposure prophylaxis along with co-delivery of hormonal contraceptive in order to evaluate multipurpose prevention technology.

In a late breaker oral abstract session, the investigators presented preclinical pharmacokinetic results from a 3-year research project funded by the United States Agency for International Development.

The purpose of the research is to develop a MAP for CAB LA through phase 1 clinical readiness. The investigators created a target product profile which identified key attributes for the patch. These attributes included patch size between 20 to 140 cm2 which is similar to commercially available transdermal patches, an ideal wear-time of 20 minutes, weekly or monthly administration to achieve therapeutic efficacy, and simple instructions that lead to successful self-administration.

“We successfully formulated and optimized MAP projection geometry to accommodate high drug-loading requirements of CAB LA (5.86 mg CAB LA per 1 cm² MAP), a hydrophobic drug,” the authors wrote in their abstract. “The MAPs are stable for 6 months under accelerated aging conditions in foil packaging, readily pierce the skin, and rapidly dissolve.”

When evaluated in rats, plasma concentration levels of CAB LA were maintained above therapeutic targets of 4xPA-IC90 for 28 days; however, bioavailability was lower than intramuscular or intradermal injections.

The authors note that further development is needed. Future research should focus on optimizing bioavailability as well as evaluating MAPs as a maintenance dose in vivo. Additionally, future research is warranted on the cost of both manufacturing and delivery analyses and an assessment on the potential end-user acceptability.

The abstract, Microarray Patch Delivery of Long-Acting HIV PrEP and Contraception, was presented in a late breaker session on Friday, October 4, 2019, at IDWeek 2019 in Washington DC.