Dolutegravir and lamivudine maintenance therapy in HIV-1 virologically suppressed patients: results of the ANRS 167 trial (LAMIDOL).

Objectives: To evaluate the dolutegravir+lamivudine combination in virologically suppressed patients living with HIV.

Methods: The ANRS 167 LAMIDOL trial was an open-label, single arm, multicentre trial assessing once-daily dolutegravir (50 mg)+lamivudine (300 mg) in virologically suppressed HIV-1 patients on first-line triple-drug regimens. The main criteria for inclusion in the trial were plasma viral load (pVL) ≤50 copies/mL for ≥2 years, CD4 nadir >200 cells/mm3 and WT HIV prior to treatment initiation. From week -8 (W-8) to day 0 (D0) (Phase 1), the current third agent was switched to dolutegravir. From D0 to W48 (Phase 2), patients received once-daily dolutegravir+lamivudine, except if intolerant or if pVL >50 copies/mL during Phase 1. Virological failure was defined as pVL >50 copies/mL in two consecutive samples. The study was designed to show that the strategy had an efficacy of ≥80%, assuming a 90% success rate with a type I error of 5% and a power of 90%.

Results: In total, 104 of 110 patients enrolled in Phase 1 were included in Phase 2. These 104 patients were 86% male, 72% MSM and 87% CDC stage A. Their characteristics were (median): age 45 years, CD4 nadir 339 cells/mm3, baseline CD4 743 cells/mm3 and duration of viral suppression 4.5 years. The overall success rate at W48 was 97% (95% CI: 94%-100%), meeting the design expectation/assumption. Three therapeutic failures occurred: one virological failure at W4, one lost to follow-up at W32 and one interruption of therapeutic strategy at W40 after a blip (pVL 59 copies/mL but control pVL <50 copies/mL). Three viral blips occurred in two additional patients. Neither M184V nor integrase resistance mutations were detected after failure or blips.

Conclusions: Dolutegravir+lamivudine is a promising maintenance therapy in HIV-1-infected patients with controlled virological suppression.