Effectiveness, Durability, and Safety of Dolutegravir and Lamivudine Versus Dolutegravir, Lamivudine, and Abacavir in a Real-Life Cohort of HIV-Infected Adults

Background: Dolutegravir (DTG) plus lamivudine (2-DR) is suggested as an initial and switch option in HIV-1 treatment. Objective: To analyze the effectiveness, durability, and safety of 2-DR compared with DTG plus abacavir/lamivudine (3-DR). Methods: This was an observational, ambispective study that included all treatment-naive (TN) and treatment-experienced (TE) patients who started 2-DR or 3-DR between July 1, 2018, and November 30, 2020. The primary end point was noninferiority, at 24 and 48 weeks, of 2-DR versus 3-DR regarding the percentage of patients with viral load (VL)>= 50 and 200 copies/mL in TN (4% margin) and VL<50 and 200 copies/mL in TE (margin 12%). Durability of response, and safety were also measured. Results: 242 patients were included (53 TN and 189 TE). Two TN patients on 2-DR had VL >= 50 copies/mL and 1 had VL >= 200 copies/mL at week 24. In TE patients on 2-DR, 90.2% achieved VL<200 copies/mL at week 24 (difference: 3.8%; 95% CI = -6.3% to 14%) and 91.8% at week 48 (difference: 0.06%; 95% CI = -9% to 10%), meeting noninferiority criteria. Among the 53 TN patients, only 1 VF was observed in 2-DR. In TN patients, the risk of treatment discontinuation was similar between groups (hazard ratio [HR] = 0.37; P = 0.15); similar rates were also found in TE patients (HR = 0.94; P = 0.85). TE patients on 2-DR showed a better safety profile compared with 3-DR patients (P<0.001). Conclusion and Relevance: Our results did not show noninferiority in terms of virological effectiveness. Nevertheless, all effectiveness measures support the use of 2-DR in a real-life cohort of TN and TE. Additionally, durability and safety of 2-DR were confirmed to be similar to that of 3-DR.

Automated summary

The study did not demonstrate noninferiority in terms of virological effectiveness, but all effectiveness measures supported the use of Dolutegravir plus Lamivudine as an initial and switch option in a real-life cohort of treatment-naive and treatment-experienced patients. Additionally, the durability and safety of 2-DR were confirmed to be similar to that of 3-DR.