Dolutegravir plus lamivudine dual therapy - a new option for initial antiretroviral therapy

The current standard of care for treating HIV infection is the use of three antiretroviral drugs: a combination of two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) and a third agent from either the integrase strand transfer inhibitor (INSTI), boosted protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) classes. In an effort to minimize the long-term adverse effects and cost of antiretroviral therapy, the use of regimens with fewer drugs in the combination has been under active investigation. To this end, the combination of dolutegravir (DTG) plus lamivudine (3TC), two antiretroviral drugs with a long track record of efficacy and safety in the treatment of HIV infection, is undergoing clinical evaluation in treatment-naive HIV-infected participants. The promising results of the PADDLE study, with 90% of study participants achieving the primary endpoint of HIV-1 RNA lower than 50 copies/mL, were confirmed by the results of ACTG A5353, a phase II, single-arm, open-label study. Subsequently, GEMINI-1 and -2, two phase III, double-blind, noninferiority studies, compared DTG + 3TC to a three-drug regimen of DTG, tenofovir disoproxil fumarate and emtricitabine in 1,433 antiretroviral treatment-naive adults, and demonstrated noninferior efficacy at 48 weeks with no emergence of NRTI or INSTI mutations and a more favorable safety profile. This dual regimen should be avoided in those patients with existing mutations and chronic hepatitis B virus infection. In addition, data in patients with CD4 counts less than 200/mm3 is limited.