Currently, it is already possible to prevent HIV infection thanks, above all, to pre-exposure prophylaxis (PrEP), however, for it to be effective it is essential to have adequate adherence to treatment and many patients do not take the medication as scheduled, or even forget it . Now a new therapeutic approach could solve this problem. It is a rechargeable implant that is placed under the skin and is responsible for administering antiretroviral drugs continuously for up to 20 months.
The new implant is made of titanium and has been successfully tested in rhesus macaque monkeys. “Forgetting to take oral pills or injections reduces the effectiveness of PrEP and therefore increases the chances of contracting HIV,” said Alessandro Grattoni, chair of the Department of Nanomedicine at the Houston Methodist Research Institute and author of the study. , which adds that there is also no way to reverse a possible adverse reaction in a patient after receiving a PrEP injection.
However, he says, the implant solves these problems and, so far, tests in non-human primates suggest that it is a safe technique and that it offers full protection against HIV infection, although the results of animal research do not they always carry over to humans. The findings have been published in Science Translational Medicine.
Administer antivirals safely and prolonged
The implants are specifically designed to prevent leakage and rupture, and hold about 0.57 milliliters of the experimental antiviral drug islatravir (ISL). The researchers tested these implants with an injectable formulation of the drug in non-human primates, where they were shown to be safe and maintained protective concentrations of the drug in blood, rectal and vaginal tissues for 20 months.
“Our implant offers flexibility for combination with other antiretroviral drugs, such as tenofovir alafenamide or cabotegravir, and has potential for the addition of contraceptive drugs”
In addition, they met their goal of fully protecting animals from simian immunodeficiency virus infections after repeated exposures. As planned the ISL drug was successfully delivered through the implant and into the bloodstream of each animal. And the researchers explained that throughout the study the concentrations of ISL in circulating blood matched the desired levels of protection that would have been observed if ISL had been administered to the monkeys as a weekly pill. “Our implant offers flexibility for combination with other antiretroviral drugs, such as tenofovir alafenamide or cabotegravir, and has potential for the addition of contraceptive drugs,” the authors said.
Grattoni has stated that “The next steps are to determine what is the lowest dose necessary for continued protection, and whether the implant is effective against different routes of HIV infection, [tanto] injection drug users as sexual”. The researcher said that they are now preparing to conduct a human trial, “and we expect clinical trials within three years. If all goes well with human trials, we believe the implant could be available within five years.”
In statements collected by SMC Spain, Josep Mallolas, head of the HIV-AIDS unit at the Clínic Hospital in Barcelona, states that “it is a high-quality study. Parenteral administration of long-acting antiretroviral drugs has recently begun, and in the future it is hoped that subcutaneous injection options or reservoirs will be available. A long-standing theoretical option is the one analyzed in the article: islatravir in a refillable subcutaneous reservoir with long action for almost two years with excellent results”, which would mean “a great advance in the prevention of infection”.
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