Background and importance A non-comparative study, a randomised pilot clinical trial and a cohort suggest that the change is virologically safe. There are still no results from two large randomised clinical trials in development. In naive patients, this pattern has shown no inferiority of dolutegravir and lamivudine compared with triple treatment with dolutegravir plus tenofovir/emtricitabine.

Aim and objectives To evaluate the efficacy, economic impact and reduction in adverse effects in HIV patients undergoing bi-therapy treatment with dolutegravir and lamivudine.

Material and methods A retrospective observational study was conducted in a second level hospital. Patients who started antiretroviral treatment or switched to dual therapy based on lamivudine and dolutegravir between June 2018 and September 2019 were included. Study variables were age, sex, date and reason for the change, duration of treatment, viral load (CV, copies/mL), CD4 and CD8 cells (cells/µL) before and after the change and on the date of the last available analysis, previous therapy, glomerular filtration rate (GFR) (mL/min), and levels of cholesterol (mg/dL), low density lipoprotein (LDL, mg/dL) and triglycerides (mg/dL).

Results Nine patients (66.66% men) with a mean age of 49 years (30–58), 3 of whom were naive patients (33.33%) were analysed. Effectiveness was 100% of patients who achieved CV <50 copies at 4–6 weeks, maintaining the virological response for an average of 26 weeks. CD4 and CD8 counts increased significantly from 690 to 805 and 910 to 943, respectively. The lipid profile showed differences in LDL from 170 to 120. A significant decrease in GFR was observed from 102 to 87. The annual cost saw a decrease of 1690€/patient/year.

Conclusion and relevance Simplification to dual therapy was a safe and effective option that allowed optimisation of the resources against triple therapy.

References and/or acknowledgements 1. Taiwo BO, Marconi VC, Berzins B, et al. Dolutegravir plus lamivudine maintains human immunodeficiency virus-1 suppression through week 48 in a pilot randomised trial. Clin Infect Dis 2018;66:1794–1797.

2. Cahn P, Sierra Madero J, Arribas J, et al. Non-inferior efficacy of dolutegravir (DTG) plus lamivudine (3TC) versus DTG plus tenofovir/emtricitabine (TDF/FTC) fixed-dose combination in antiretroviral treatment-naïve adults with HIV-1 infection: 48-week results from the GEMINI studies. 22nd International AIDS Conference, 23–27 July 2018, Amsterdam. Abstract TUAB0106LB.

No conflict of interest.