SEATTLE — A two-drug regimen for treating HIV-1 could become an alternative to three- or four-drug regimens in the future, according to a pair of studies presented here.
At 48 weeks of treatment, a combination of Tivicay (dolutegravir,ViiV Healthcare) and Edurant (rilpivirine, Janssen) was noninferior to the current multidrug regimen in virologically suppressed patients in the SWORD I and II studies.
“It has been a long-term dream to try to identify safe strategies that can control the disease with a reduced number of drugs in particular subjects,” study researcher Josep M. Llibre, MD, from the Hospital Universitari Germans Trias i Pujol, in Barcelona, Spain, said during a press conference.
“It’s the first time that we can prove a two-drug combination with an integrase inhibitor and a non-nucleoside reverse transcriptase inhibitor is noninferior in a once-daily regimen … This opens the door to new two-drug regimen strategies that will come in the future.”
The twin, identically designed randomized global studies included 1,024 patients. In all, 513 of the patients switched to the dolutegravir/rilpivirine combination (DTG+RPV) and 511 continued with their current antiretroviral regimen (CAR).
At 48 weeks of treatment, 95% of each group achieved viral suppression with HIV-1 RNA of less than 50 copies/mL.
Patients had been receiving ART at a median of a little more than 4 years. The most commonly reported adverse effects (> 5%) for both groups were nasopharyngitis, headache, diarrhea and upper respiratory tract infection. Back pain was an additional commonly reported effect for the CAR group.
Twenty-seven serious adverse events were reported among the DTG+RPV patients, and 21 serious adverse events were reported among the CAR group.
Virologic failure rates were low for both groups, recorded at less than 1% for the DTG+RPV patients and 1% for the CAR patients. The dolutegravir and rilpivirine safety profiles were consistent with their product labeling, researchers said. No unexpected adverse events were identified using this new combination.
Llibre said dolutegravir and rilpivirine are being taken in separate pills for the SWORD studies, but the goal is to provide both drugs in a single pill taken once a day. With only 75 mg of active drugs, it could be the smallest single tablet regimen so far.
The SWORD I and II studies will last a total of 148 weeks. The current results were reported on the same day that Gilead Sciences presented data from a clinical trial of its investigational HIV drug bictegravir, also at CROI.
That phase 2 study showed that bictegravir was effective and well-tolerated compared with dolutegravir. – by Joe Green
Llibre JM, et al. Phase III SWORD 1 & 2: Switch to DTG+RPV maintains virologic suppression through 48 weeks. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 13-16, 2017; Seattle.
Sax PE, et al. Abstract 41. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 13-16, 2017; Seattle.
Disclosure: The researchers report no relevant financial disclosures.