Positive results from the LATTE-2 study have been reported at the Conference on Retroviruses and Opportunistic Infections in Boston. Interim results were announced in November 2015.
LATTE-2 is an ongoing phase 2b, parallel-group, open-label study investigating long-acting, injectable formulations of cabotegravir (ViiV Healthcare) and rilpivirine (Edurant, Janssen Sciences Ireland) as a two-drug treatment for patients with human immunodeficiency virus-1 (HIV-1) infection who have already achieved HIV viral suppression with a three-drug oral regimen of cabotegravir plus two nucleoside reverse transcriptase inhibitors (NRTIs).
The study included 309 HIV-infected adults. The subjects were suppressed virologically (HIV-1 RNA of less than 50 copies/mL) during a 20-week induction period with daily oral cabotegravir (30 mg) plus two NRTIs and were subsequently assigned to one of three study arms during the maintenance period: an intramuscular (IM) cabotegravir long-acting formulation (400 mg) plus a rilpivirine long-acting formulation (600 mg) every four weeks; an IM cabotegravir long-acting formulation (600 mg) plus a rilpivirine long-acting formulation (900 mg) every eight weeks; or oral cabotegravir (30 mg) plus two NRTIs. The subjects will receive up to 104 weeks of treatment.
The study’s primary endpoint evaluated antiviral activity and safety through 32 weeks of maintenance therapy. At this time point, viral suppression rates for the two-drug regimen dosed every eight weeks (95%) or every four weeks (94%) were comparable with the rate observed in patients continuing with a three-drug oral regimen (91%). One patient in the eight- week dosing group and one patient in the oral regimen group met protocol-defined virological failure criteria; neither patient had evidence of resistance at failure.
The most common drug-related adverse event (AE) reported by patients receiving injectable study medication was injection- site pain (92%), which was usually mild (82%) or moderate (17%) in severity.
The most commonly reported AEs not related to injection-site reactions in the injectable-treatment groups included nasopharyngitis (20%), headache (14%), and diarrhea (12%). For the patients assigned to oral treatment, the most common AEs during the maintenance period were nasopharyngitis (25%), headache (7%), and diarrhea (5%). Serious AEs occurred in 6% of patients receiving injectable treatment (one drug-related) and in 5% of patients receiving oral cabotegravir (none drug-related). One patient in the eight-week injectable treatment group died from an event unrelated to the study drug (seizure). Nine patients withdrew from the study because of AEs. Laboratory abnormalities were noted in 16% of the injectable treatment group and in 14% of the oral treatment group through week 32.
Cabotegravir, an analogue of dolutegravir, is an investigational integrase strand transfer inhibitor. It is being developed for the treatment and prevention of HIV infection and is currently being evaluated as a once-daily oral tablet formulation and as a long-acting nanosuspension formulation for IM injection.
Rilpivirine is a prescription HIV medication that is used with other antiretroviral drugs to treat HIV-1 infection in patients who have never received HIV medications and who have a viral load that does not exceed 100,000 copies/mL.
Source: ViiV Healthcare; February 23, 2016.