Effectiveness and safety of dual therapy with co-packaged dolutegravir and lamivudine compared to triple therapy as switching strategy in clinical practice.

Introduction: Dolutegravir plus lamivudine (DTG/3TC) dual therapy has demonstrated efficacy in HIV treatment, but access remains challenging in Latin America. Argentina approved a generic co-packaged DTG+3TC presentation to improve accessibility. This study evaluated the effectiveness and safety of co-packed DTG/3TC compared to DTG-based triple therapy in clinical practice.

Materials and methods: A retrospective observational cohort study conducted between October 2019 and November 2023 at a reference HIV center in Argentina. Treatment-experienced people living with HIV (PLWH) with viral suppression who switched to either co-packaged DTG/3TC or DTG-based triple therapy were included. Primary outcomes included persistence, virologic suppression rates (VSR), and safety at 6, 12, and 18 months.

Results: Of 599 PLWH, 245 (41%) switched to dual therapy and 354 (59%) to triple therapy. Persistence rates for dual therapy at 6, 12, and 18 months were 99%, 100% and 98%; for triple therapy: 99%, 97% and 97%, respectively. VSR for dual therapy were 99%, 98% and 99%; for triple therapy: 99%, 97% and 98% at the same timepoints. Adverse event rates were low in both groups: dual therapy (0.5%, 0%, 0.8% at 6, 12, 18 months) and triple therapy (1.2%, 0.7%, 0.4% at 6, 12, 18 months).

Conclusions: Co-packaged DTG/3TC demonstrated high persistence and virologic suppression rates with a favorable safety profile in clinical practice. Its effectiveness and safety were comparable to DTG-based triple therapy, supporting its use as a cost-effective alternative for treatment-experienced PLWH in resource-limited settings.