When first proposed, the concept of long-acting injectable antiretroviral therapy (ART) met with a good measure of skepticism from HIV providers who had difficulty seeing the value of a treatment involving needles and clinic visits every two months or so in an era of once-a-day pill sparkly goodness. With time (and data) attitudes can change, and over the past year there has been a shift toward acceptance of long-acting ART and its possibilities.
In 2015, 96-week data from the LATTE trial, a proof-of-concept study that examined the maintenance of viral suppression with oral cabotegravir and rilpivirine (Edurant), was presented at the Conference on Retroviruses and Opportunistic Infections (CROI). Among those who achieved viral suppression after 24 weeks of either efavirenz (Sustiva, Stocrin) + two NRTIs (nucleoside reverse transcriptase inhibitors) or cabotegravir (at one of three doses) + two NRTIs, the simplified integrase-NNRTI (non-nucleoside reverse transcriptase inhibitor) combo kept viremia at bay better than continued therapy with the efavirenz-based regimen.
The follow-on LATTE-2 trial looked at use of actual long-acting injectable formulations of cabotegravir and rilpivirine as maintenance therapy following suppression with oral cabotegravir + two NRTIs. The injected meds were administered either every four or eight weeks and were compared to continued oral therapy with cabotegravir + two NRTIs. Rates of viral suppression at 32 weeks were high (>90%) in all three arms. Reportedly, the injections were well tolerated with only two of 230 participants assigned to the injections withdrawing for injection site reactions. Other details are forthcoming, as the results were reported not at a conference or in a medical journal, but in a press release (clearly the intended audience was less prescribers and more shareholders).
The Bottom Line
Long-acting ART is a next frontier of HIV therapeutics and will provide creative options for treating patients who are tiring of taking pills or are simply one of the many who identify as not being "pill people." That the eight-week dosing schedule proved to be effective in LATTE-2 is a relief.
Although at first glance long-acting injected ART would seem to be ideal for the super non-adherent, the image of trying to track down patients who are weeks passed their scheduled injection and have slowly declining levels of rilpivirine and cabotegravir in their blood should shut that notion down but quick. In addition, a several-weeks-long oral lead-in phase will be required to make sure the drugs are tolerated before being injected, and this will require decent pill-taking behavior.
Therefore, these injectable agents offer promise, but the companies who make them must invest not only in bringing them to market but also in strategies that bring them to patients in ways that support their proper use. Such initiatives are not the stuff of press releases, but are plain smart and the right thing to do.
What are some other top clinical developments of 2015? Read more of Dr. Wohl's picks.
David Alain Wohl, M.D., is an associate professor of medicine in the Division of Infectious Diseases at the University of North Carolina and site leader of the University of North Carolina AIDS Clinical Trials Unit at Chapel Hill.