ViiV Healthcare has presented three-year data from a clinical trial of a long-acting injectable formulation of cabotegravir and Edurant (rilpivirine), indicating that the regimen is safe and effective as HIV treatment when given every four or eight weeks.

Presenting their findings at the HIV Glasgow Drug Therapy meeting in Scotland, researchers conducted a Phase II multicenter, parallel group open-label trial, called LATTE-2, of intramuscular injections of long-acting cabotegravir and Edurant.

Edurant is a non-nucleoside reverse transcriptase inhibitor (NNRTI); cabotegravir is an integrase inhibitor.

After a 20-week period during which HIV-positive participants received oral therapy with cabotegravir and Epzicom (abacavir/lamivudine), virally suppressed participants were randomly assigned two to two to one to receive long-acting injectable cabotegravir and Edurant every eight weeks or every four weeks or to stay on the oral three-drug regimen. After 96 weeks of oral treatment, those in the oral treatment group were permitted to choose either dosing interval of the injectable regimen.

After 160 weeks of treatment, 90 percent (104 or 115) of those in the four-week injectable dosing group and 83 percent (95 of 115) of those in the eight-week injectable dosing group remained virally suppressed. At this point in the study, of those in the oral treatment group who elected to switch to injectable treatment at week 96, 97 percent (33 of 34) of those in the eight-week group and 100 (10 of 10) of those in the four-week group were virally suppressed.

Through week 48 of the trial, two participants in the eight-week group developed virologic failure, including one who developed resistance to the NNRTI and integrase inhibitor classes of antiretrovirals.

No other cases of virologic failure occurred through week 160 of the study.

Most of the participants reported side effects at the injection site, 85 percent of which were mild and 14 percent of which were moderate. Eighty-seven percent of these reactions resolved within one week of a participant receiving an injection.

Outside of injection-site reactions, the most common adverse health events reported by participants were symptoms of the common cold (38 percent of participants), diarrhea (22 percent) and headache (22 percent). Three percent (3 of 115) of those in the eight-week dosing group and 10 percent (12 of 115) of those in the four-week dosing group had adverse health events causing them to withdraw from the study or discontinue treatment.

Three (1 percent) of the 274 individuals who received injectable treatment during the study discontinued treatment due to injection-site reactions.

To read a press release about the study, click here.