HIV Prevention, Treatment: Playing the Long Game
Despite decades of research, there is still no vaccine against HIV. As a result, pre-exposure prophylaxis (PrEP) has emerged as the most promising preventive strategy against the virus that causes AIDS. PrEP is the use of antiretroviral medications by HIV-negative individuals who are at risk of contracting the disease to reduce that risk. But the PrEP regimens have involved taking a pill on a daily basis, which makes them candidates for nonadherence.
On Dec. 20, 2021, the FDA approved Apretude (cabotegravir extended-release injectable suspension), the first injectable formulation of PrEP. Instead of daily pills, Apretude will involve getting an injection in the muscle of the buttock by a healthcare professional every other month, (the first two shots are given a month apart).
“It will not be for everyone; some people may want to continue with a daily oral pill,” notes Carl Schmid, executive director of the HIV+Hepatitis Policy Institute, an advocacy organization funded by several pharmaceutical companies. “They are fairly easy to take and there are limited side effects.”
Gilead’s PrEP formulation, Truvada (tenofovir disoproxil fumarate and emtricitabine), was approved in 2012. The company also developed Descovy (tenofovir alafenamide and emtricitabine) for PrEP.
Generic versions of Truvada have come on the market since, particularly in the past year, and prices have dropped. GoodRx’s lowest price for a 30-day supply of the most common version of generic Truvada is about $35, although under the ACA, health plans are required to cover 100% of the cost of the PrEP because it is deemed a preventive service.
Use of PrEP has fallen off during the pandemic, partly because people haven’t been socializing in person as much and engaging in the risky behavior that would warrant taking the antiviral medications on a prophylactic basis. But before the pandemic, prescriptions were increasing.
CDC says about 25% of the 1.2 million people for whom PrEP is recommended were prescribed it in 2020, compared with about 3% in 2015. The agency credits PrEP and other factors with reducing the HIV incidence. New infections fell from 37,800 in 2015 to 34,800 in 2019, an 8% decrease.
Drugmakers are also working on long-acting drugs for HIV treatment as well as for PrEP. The FDA approved Cabenuva (cabotegravir and rilpivirine, injectable formulation), an injectable, once-a-month HIV treatment, in January 2021. Most companies involved in HIV research are developing long-acting drugs for both treatment and prevention, Schmid says.
“We are at the beginning stages for both and can look forward to once-monthly oral regimens, once-every-6-month injectables, or once-a-year implants in the future.”
Theodore Gideonse, Ph.D., an assistant professor of teaching, program in public health, at the University of California, Irvine, notes that Gilead also has a very promising injectable for both treatment and PrEP called lenacapavir. “It is a bit further away from approval, but it will be a huge deal if and when it’s approved,” he says. That approval may be a ways off, though.
In December, the FDA put a hold on trials of injectable lenacapavir because of concerns about vials made of borosilicate glass and the formation of subvisible glass particles in the solution. Merck’s investigational HIV drug, islatravir, has also run into problems. The FDA put a hold on trials of islatravir in December after the drug was associated with drops in lymphocyte and CD4 cell counts.