"If you take the drugs they work, it you don’t they don’t work." Ho said, simplifying the problem with nonadherence. "Long acting agents will take human behavior out of the equation."
"How do you administer long-lasting antiretrovirals administered to high risk individuals?" He asked rhetorically, before spelling out the answers: One: he said, through potent and broad virus-neutralizing monoclonal antibodies. Two: through slow-release formulationof antiretroviral drugs. "Cabotegravir (GSK 744) is a potent integrase inhibitor of HIV. This drug has unusual physical properties: a high melting point, low water solubility, high potency, low metabolic clearance, and can be put into an injectable."
"Will this be protective against HIV infection?" Dr. Ho wondered, considering the potential of a long-acting PrEP. Recent experiments to answer that question involved 16 monkeys, divided into two groups. Both were exposed to the simian version of the HIV virus rectally. One group was injected with Cabotegravir, and, among them, there were no HIV infections a the eight-week point. In a related intravaginal study, six out of eight monkeys did not acquire SIV upon exposure when using the drug. Ho summarized the findings regarding using Cabotegravir as a long-acting PrEP agent:
"It proves highly protective against intrarectal, intravaginal, and intravenous virus challenges in monkey studies." They have already completed Phase 1 and Phase 2 human studies. So far, "over 1000 subjects having received the drug; and they have an outstanding tolerability profile and none to minimal side effects."
Several Phase 3 studies to measure protective efficacy anticipated in different high-risk populations, (gay men and black women) will begin soon.
Long-acting injectables are the future of HIV treatment and prevention. And that is good news, indeed.