Two-drug regimens may be as effective and safe as multi-drug therapies, according to investigators evaluating paired down treatment options for HIV.
“I don’t mean to say that everyone should be on dual therapy,” but it could be the beginning of a new era in HIV treatment, said Pedro Cahn, MD, from the Buenos Aires University Medical School in Argentina.
Previous attempts to treat people living with HIV with only two drugs were found to be ineffective at suppressing the HIV virus and led to drug resistance.
But results from a prespecified secondary analysis of data from the GEMINI studies (NCT02831673 and NCT02831764), presented here at the International AIDS Society (IAS) 2019 Conference on HIV Science, showed that the two-drug regimen of dolutegravir and lamivudine (Dovato, ViiV Healthcare) suppresses HIV in people new to treatment for 96 weeks, with zero drug-resistant mutations.
Also presented at the meeting were results from the TANGO study (NCT03446573), which demonstrated that the combination of dolutegravir and lamivudine is as effective, as durable, and as free of resistance at 48 weeks as traditional triple therapy in people who switch from three-drug regimens, and results from a phase 2b trial of 121 people that showed that islatravir, Merck’s investigational agent, plus doravirine is as safe and effective as a three-drug regimen at 48 weeks.
These findings add to the body of evidence established by the SWORD 1 and 2 trials, which showed that dolutegravir plus rilpivirine is effective in people switching from three-drug regimens.
Together, the findings provide an opportunity “to think about the position of dual therapy in international guidelines.”
GEMINI and TANGO
This time last year, Cahn was on another stage talking about similar data, At the time, the 1433 participants in GEMINI 1 and 2 had been on their new regimen for 48 weeks. Rates of viral loads below 50 copies/mL were comparable in patients treated with the two-drug and three-drug regimens in GEMINI 1 (90% vs 93%) and GEMINI 2 (93% vs 94%).
At 48 weeks, the rate of viral suppression (<50 copies/mL) was similar in the dolutegravir plus lamivudine group and the dolutegravir plus tenofovir disoproxil fumarate and emtracitabine (Truvada, Gilead Sciences) group (91.5% vs 93.3%).
But when Cahn presented those data last year, there were questions about the durability of the response and whether resistance could develop.
This year, Cahn was able to report that the response is durable and resistance did not develop. The combination of dolutegravir plus lamivudine “has been shown to be as effective as triple therapy,” he explained.