CROI 2016: Long-Acting Injectable Cabotegravir + Rilpivirine Works Well as HIV Maintenance Therapy

alt

A combination of 2 long-acting injectable antiretrovirals, cabotegravir and rilpivirine, given once every 4 or 8 weeks, maintained viral suppression as well as standard oral antiretroviral therapy (ART) and appeared safe and well-tolerated, according to results from the LATTE 2 trial presented at the Conference on Retroviruses and Opportunistic Infections (CROI 2016) taking place this week in Boston.

Long-acting medications could offer an attractive option for people with HIV facing a lifetime of antiretroviral treatment. These agents have the advantage of being more convenient and potentially improving adherence, but the drawback is that a long-lasting drug cannot be easily removed from the body, so it is especially important to establish safety in advance.

To this end, the LATTE (Long-Acting Antiretroviral Treatment Enabling) trial evaluated ViiV Healthcare's experimental integrase inhibitor cabotegravir (formerly GSK1265744) and Janssen's NNRTI rilpivirine (Edurant) as a simplified 2-drug oral maintenance regimen for people who had already achieved undetectable viral load using standard 3-drug ART.

At last year's CROI David Margolis from ViiV presented 96-week findings showing that 76% of participants who switched to oral cabotegravir plus rilpivirine dual therapy maintained viral suppression, compared to 63% of people who stayed on a 3-drug regimen containing efavirenz (Sustiva); these results were also published in the October 2015 edition of Lancet Infectious Diseases.

The oral combination was safe and well-tolerated, which laid the groundwork for testing the long-acting injectable formulations of cabotegravir and raltegravir in the phase LATTE 2 trial (NCT02120352). Margolis presented 32-week results from LATTE 2 at this year's conference.

This Phase 2b analysis included 309 previously untreated HIV-positive participants. More than 90% were men, about 80% were white, and the median age was 35 years. At baseline the median CD4 T-cell count was 489 cells/mm3 and nearly one-fifth had a high viral load >100,000 copies/ml.

Participants in this open-label study first started a 3-drug induction regimen consisting of 30 mg once-daily cabotegravir plus abacavir/lamivudine (the drugs in Epzicom or Kivexa).

Those who achieved viral suppression (<50 copies/mL) during the induction period were randomly assigned either to receive intramuscular injections of cabotegravir and rilpivirine every 4 weeks (Q4W) or every 8 weeks (Q8W), or to stay on the same oral regimen. Previous research showed that injectable cabotegravir remains at therapeutic levels with either monthly or quarterly dosing.

The injectable regimen consists of separate 2-3 ml injections of cabotegravir and rilpivirine in the buttocks. Margolis suggested injections in the thigh might be possible to allow self-administration. He said there is some flexibility in dosing, so people can get the shots within a week before or after their scheduled date.

Results

Study participants reported a high level of satisfaction with their treatment -- more than 90% receiving the long-acting injections reported that they were satisfied, compared with about 70% of those on the oral regimen.

Neither the Q4W or Q8W dosing regimen was clearly better. LATTE 2 follow-up will continue through week 96 and researchers plan to further evaluate the long-acting injectable regimen in larger Phase 3 trials.

The long-acting formulations of cabotegravir and rilpivirine are also being studied for pre-exposure prophylaxis, or PrEP -- data that are also being presented this week at CROI.

2/23/16

Reference

DA Margolis, J González-García; H-J Stellbrink et al. Cabotegravir+Rilpivirine as Long-Acting Maintenance Therapy: LATTE-2 Week 32 Results.Conference on Retroviruses and Opportunistic Infections. Boston, February 22-25, 2016. Abstract 31LB.

Other Source

ViiV Healthcare. ViiV Healthcare announces phase II study results for first two drug, long-acting injectable regimen for HIV-1 treatment. Press release. February 23, 2016.