Switching to a 2-drug regimen of dolutegravir plus rilpivirine maintained viral suppression among people on successful 3- or 4-drug antiretroviral therapy (ART) in a pair of Phase 3 clinical trials, according to a recent announcement from ViiV Healthcare.
HIV and Hepatitis reports that ViiV’s dolutegravir (Tivicay, also in the Triumeq single-tablet regimen) is a potent integrase inhibitor with a high barrier to resistance. Janssen/Johnson & Johnson‘s rilpivirine (Edurant, also in the Complera or Eviplera combination pills) is a non-nucleoside reverse transcriptase inhibitor.
SWORD-1 (NCT02429791) and SWORD-2 (NCT02422797) are Phase 3 studies evaluating the safety and efficacy of switching people with undetectable viral load from a standard 3- or 4-drug antiretroviral regimen to dolutegravir plus rilpivirine. These parallel studies each enrolled about 500 participants.
Participants in these open-label trials were assigned to either switch to once-daily dolutegravir plus rilpivirine or remain on their current regimen containing an integrase inhibitor, NNRTI, or boosted protease inhibitor.After a year, the current therapy group will also switch to the dual regimen.
The study met its primary endpoint, showing that dolutegravir plus rilpivirine was non-inferior to staying on current therapy, with similar proportions of patients maintaining HIV RNA
Secondary endpoints will include viral resistance and safety and tolerability measures including changes in kidney, bone, and cardiovascular biomarkers. The company said detailed results will be presented at an upcoming scientific meeting (likely the Conference on Retroviruses and Opportunistic Infections next February in Seattle).
“These are important results for the HIV scientific community and represent an important milestone in our understanding of how HIV can be treated,” said ViiV CEO Dominique Limet. “The results support our strategy of investigating 2-drug regimens as innovative treatment options for people living with HIV and we are planning regulatory submissions for this 2-drug regimen as a single tablet in 2017.”
The SWORD studies are the first large Phase 3 trials to demonstrate the efficacy of 2-drug maintenance therapy, according to ViiV. A regimen using fewer drugs could potentially reduce side effects, drug interactions, and cost.
At the International Aids Conference in July, researchers reported results from PADDLE, a small pilot study showing that a dual regimen ofdolutegravir plus lamivudine (Epivir and generic equivalents) led to sustained viral suppression at 48 weeks for most people starting ART or the first time. The Phase 3 GEMINI trial (NCT02831673) is testing this regimen in a larger study. Other small studies have suggested that even dolutegravir alone may be potent enough to maintain viral suppression in some patients.