TANGO Study Meets Primary Endpoint at 48 Weeks

The TANGO study evaluating the 2-drug regimen of dolutegravir plus lamivudine has met its primary endpoint, according to Week 48 results announced by ViiV Healthcare today.

The phase 3 randomized, open-label, active-controlled, multicenter study is assessing the switch to a 2-drug regimen (2DR) consisting of dolutegravir plus lamivudine in adults with HIV-1 who had maintained viral suppression for at least 6 months on a tenofovir alafenamide fumarate (TAF)-containing regimen of at least 3 drugs. The study is analyzing whether adults who make the switch are able to maintain similar rates of viral suppression, compared with a group of adults continuing on the TAF-containing regimen.

Dolutegravir plus lamivudine is a once-daily, single-pill, 2DR that combines the integrase inhibitor (INI) dolutegravir (Tivicay, 50 mg) with the nucleoside reverse transcriptase inhibitor (NRTI) lamivudine (Epivir, 300 mg).

The news today reports that TANGO met its primary endpoint for non-inferiority based on the proportion of participants with plasma HIV-1 RNA > 50 copies per milliliter using the US Food and Drug Administration (FDA) Snapshot algorithm at Week 48. No patients in the dolutegravir plus lamivudine arm of the study met confirmed virologic withdrawal criteria or developed treatment resistance.

The study enrolled participants with HIV-1 infection who had been on a TAF-containing regimen with HIV-1 RNA<50c/mL for at least 6 months, and did not have a history of virologic failure, NRTI or INI major resistance mutation, and no evidence of hepatitis B infection. For the study the participants were randomized to switch to dolutegravir plus lamivudine or continue on the TAF-containing regimen through Week 148.

“When we developed the TANGO study, we asked if virally suppressed people living with HIV could reduce the number of medicines in their HIV treatment regimen while maintaining viral suppression,” Kimberly Smith, MD, head of global research & medical strategy at ViiV Healthcare, said in a press release. “These Week 48 data clearly indicate that they can—individuals who are already on treatment can maintain viral suppression if they switch from a 3-drug, TAF-containing regimen to a 2-drug regimen of dolutegravir plus lamivudine.”

Earlier this year in April, dolutegravir plus lamivudine (Dovato) was approved by the FDA for the treatment of HIV-1 in treatment-naïve adults with no known resistance to either dolutegravir or lamivudine.

“Dolutegravir lamivudine is another interesting concept for treating HIV both as initial therapy and also for people who have viral suppression," Paul Edward Sax, MD, professor of medicine at Harvard Medical School and clinical director of the Division of Infectious Diseases at Brigham and Women’s Hospital, and a member of the Contagion® Editorial Advisory Board, said in a previous interview. "So, a 2-drug approach to treating HIV could potentially offer benefits in safety—because you're not exposing people to as many drugs&mdash;as well as in cost. And so, we've done some work modeling showing that 2-drug treatment with dolutegravir and lamivudine is likely to be highly cost-effective for both people starting therapy and for people who are already successfully treated.”

ViiV indicates that full results from the TANGO study will be presented at the 10^th International AIDS Society Conference on HIV Science (IAS 2019), to be held later this month in Mexico City, Mexico.