Safety and Efficacy of Triple Therapy With Dolutegravir Plus 2 Nucleoside Reverse Transcriptase Inhibitors in Treatment-Naive Human Immunodeficiency Virus Type 2 Patients: Results From a 48-Week Phase 2 Study

Background: Integrase strand transfer inhibitor-based regimens are recommended for first-line therapy in human immunodeficiency virus type 2 (HIV-2). Nonetheless, dolutegravir (DTG) clinical trial data are lacking.

Methods: We conducted a phase 2, single-arm, open-label trial to evaluate the safety and efficacy of a triple therapy regimen that included DTG in persons with HIV-2 (PWHIV-2) in Portugal. Treatment-naive adults receive DTG in combination with 2 nucleoside reverse transcriptase inhibitors (NRTIs). Treatment efficacy was evaluated by the proportion of patients who achieved a plasma viral load (pVL) <40 copies/mL and/or by the change from baseline in CD4+ T-cell count and in CD4/CD8 ratio at week 48.

Results: A total of 30 patients were enrolled (22 women; median age, 55 years). At baseline, 17 (56.7%) individuals were viremic (median, pVL 190 copies/mL; interquartile range [IQR], 99-445). The median CD4 count was 438 cells/μL (IQR, 335-605), and the CD4/CD8 ratio was 0.8. Three patients discontinued the study. At week 48, all participants (27) had pVL <40 copies/mL. No virological failures were observed. Mean changes in CD4 count and CD4/CD8 ratio at week 48 were 95.59 cells/µL (95% confidence interval [CI], 28-163) and 0.32 (95% CI, .19 to .46). The most common drug-related adverse events were headache and nausea. One participant discontinued due to central nervous system symptoms. No serious adverse events were reported.

Conclusions: DTG plus 2 NRTIs is safe and effective as first-line treatment for PWHIV-2 with a tolerability profile previously known. No virological failures were observed that suggest a high potency of DTG in HIV-2 as occurs in HIV-1.

Clinical trials registration: M NCT03224338.