# A Stable Switch From Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/FTC/TAF) to Dolutegravir/Lamivudine (DTG/3TC) in the Absence of Historical Resistance Records: Results From the Switch to Dovato in Patients Suppressed on Biktarvy (SOUND) Cohort

## TL;DR

This study shows that switching HIV patients from B/FTC/TAF to DTG/3TC is safe and effective, even without prior resistance records, and may help reduce weight.

## Contribution

Demonstrates the safety and efficacy of switching to DTG/3TC in HIV patients without historical resistance data.

## Key findings

- 0% of participants had a viral load ≥50 c/mL at week 48 after switching regimens.
- No participants discontinued due to safety concerns or lab abnormalities.
- A significant decrease in weight was observed during the study period.

## Abstract

Objective: This article aims to examine the safety and efficacy of switching from bictegravir/emtricitabine/tenofovir alafenamide (B/FTC/TAF) to dolutegravir and lamivudine (DTG/3TC) in the absence of prior resistance records.

Design: Switch to Dovato in patients suppressed on Biktarvy (SOUND) is an open-label, single-arm, pilot study of adult people with HIV who were virologically suppressed (HIV-1 <50 copies/mL) on B/FTC/TAF for >24 weeks, and switched to DTG/3TC in the absence of available resistance records.

Methods: The primary endpoint was the percentage of participants with HIV viral load (VL) ≥50 c/mL at week 48. Secondary endpoints at weeks 48 and 96 included the percentage of participants with HIV-VL <50 c/mL, incidence and severity of adverse events, laboratory abnormalities, change in baseline CD4 cell count, and retrospective proviral DNA resistance testing on banked baseline samples.

Results: Of the 40 individuals enrolled, 0% had VL ≥50 c/mL at week 48. No participants discontinued due to laboratory abnormalities or safety-related concerns. Three participants withdrew from the study while virologically suppressed. Among the 32 baseline samples available for retrospective proviral DNA resistance testing, six (19%) had nucleoside reverse transcriptase inhibitor resistance-associated mutations (RAMs), all with M184V. Two (6%) participants had integrase strand transfer inhibitor RAMs at baseline (S147S/G and Q148Q/R); neither conferred resistance to DTG. Nonnucleoside reverse transcriptase inhibitor and protease inhibitor RAMs were observed in eight (25%) and three (9%) participants, respectively. A significant decrease in weight was observed over the study period.

Conclusions: Results from SOUND support the efficacy and safety of switching to DTG/3TC for people living with HIV-1 who are virologically suppressed on B/FTC/TAF with unknown resistance history and may confer a weight advantage.