A long-acting injectable formulation of ViiV’s cabotegravir and Janssen’s Edurant (rilpivirine), dosed every four or eight weeks, is safe and generally well tolerated and suppresses HIV as well as a daily oral regimen in an ongoing trial. The companies intend to start Phase III trials of long-acting cabotegravir/Edurant, dosed every eight weeks, later this year. If this research is successful, the treatment will likely hit the market in 2019.

The Phase IIb, ongoing, open-label, parallel group, international multicenter LATTE-2 study of the long-acting injectable formulations of experimental integrase inhibitor cabotegravir and Janssen’s non-nucleoside reverse transcriptase inhibitor (NNRTI, or non-nuke) Edurant (rilpivirine) includes 309 treatment-naive participants living with HIV. Results were presented at the 2016 Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.

Top-line results from this trial were released in November 2015.

Participants were first treated for 20 weeks with daily oral cabotegravir plus two nucleoside reverse transcriptase inhibitors (NRTIs). Then they were randomized into three groups for what was called the study’s maintenance period: They received intramuscular injections of Edurant/cabotegravir either every four or eight weeks, or they continued taking the oral regimen.

After 32 weeks of maintenance treatment, the viral suppression rates in the four- and eight-week injection groups and the oral medication group were a respective 94 percent, 95 percent and 91 percent. One participant in the eight-week dosing group and one in the oral drug group developed virologic failure. Neither of them had evidence of drug resistance.

The most commonly reported drug-related adverse health problem among those receiving the injectable drugs was injection site pain (92 percent). Eighty-two percent of these cases were mild, while 17 percent were moderate in severity. Injection site reactions lasted a median of three days, and decreased in frequency after the first dose. Such reactions led two participants (less than 1 percent) to drop out of the trials.

The most commonly reported adverse health problems not related to injection site reactions during the maintenance period were upper respiratory infection (20 percent), headache (14 percent) and diarrhea (12 percent). Six percent of participants receiving the injectable medication experienced a serious adverse health problem, one of which was related to the drug, while 5 percent of those in the oral drug group experienced such a health problem, none of which were drug related.

One person in the eight-week injectable group died from a seizure that was unrelated to the drug. Nine participants dropped out of the study because of adverse health matters. Sixteen percent of those receiving the injectable drug and 14 percent of those on the oral drugs experienced Grade 3 or above lab abnormalities.

Ninety-seven percent of those in the eight-week dosing group and 96 percent of those in the four-week dosing group said at the 32-week point that they were satisfied with their current treatment, compared with 71 percent of those in the oral drug group.

The study will continue through 104 weeks of maintenance treatment.

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