BackgroundAntiretroviral therapy (ART) in people with HIV (PWH) can lead to weight gain, but the effects of nucleoside reverse transcriptase inhibitors such as abacavir (ABC) are not well understood. In this study, we investigated whether discontinuing ABC would mitigate weight changes and metabolic complications in PWH.MethodsIn a randomized controlled trial including PWH on dolutegravir, ABC, and lamivudine (DTG/ABC/3TC), participants were randomized 2:1 to either switch to DTG/3TC or continue DTG/ABC/3TC. Data was collected at baseline, week 24, and week 48. This study was powered to detect a difference of 2 kg in weight between groups. Secondary outcomes included body composition, fat and muscle distribution, and metabolic parameters. Weight and metabolic changes were analyzed by linear mixed modeling.ResultsEighty-one participants were randomized. Switching from DTG/ABC/3TC to DTG/3TC was not associated with a significant change in weight at 48 weeks in the intention to treat (ITT) analysis (mean difference − 0.5 kg, 95% confidence interval (CI): -2.5 to 1.5, p = 0.599) or the modified ITT, (-0.1 kg, 95% CI: -1.7 to 1.5, p = 0.914). In the ITT analysis, the DTG/3TC group gained 0.4 kg ± 5.1 SD (p = 0.589) compared to 0.9 kg ± 2.3 SD (p = 0.054) in the DTG/ABC/3TC group, while in the modified ITT, the changes were 0.9 ± 3.2 kg (p = 0.054) and 0.9 ± 3.6 kg (p = 0.071), respectively. The were no differences between groups in secondary outcomes.ConclusionContinuing or discontinuing abacavir for 48 weeks was associated with modest gains in weight that did not differ between groups. Similarly, fat distribution, or metabolic parameters were comparable between groups. BACKGROUND: Antiretroviral therapy (ART) in people with HIV (PWH) can lead to weight gain, but the effects of nucleoside reverse transcriptase inhibitors such as abacavir (ABC) are not well understood. In this study, we investigated whether discontinuing ABC would mitigate weight changes and metabolic complications in PWH.METHODS: In a randomized controlled trial including PWH on dolutegravir, ABC, and lamivudine (DTG/ABC/3TC), participants were randomized 2:1 to either switch to DTG/3TC or continue DTG/ABC/3TC. Data was collected at baseline, week 24, and week 48. This study was powered to detect a difference of 2 kg in weight between groups. Secondary outcomes included body composition, fat and muscle distribution, and metabolic parameters. Weight and metabolic changes were analyzed by linear mixed modeling.RESULTS: Eighty-one participants were randomized. Switching from DTG/ABC/3TC to DTG/3TC was not associated with a significant change in weight at 48 weeks in the intention to treat (ITT) analysis (mean difference - 0.5 kg, 95% confidence interval (CI): -2.5 to 1.5, p = 0.599) or the modified ITT, (-0.1 kg, 95% CI: -1.7 to 1.5, p = 0.914). In the ITT analysis, the DTG/3TC group gained 0.4 kg ± 5.1 SD (p = 0.589) compared to 0.9 kg ± 2.3 SD (p = 0.054) in the DTG/ABC/3TC group, while in the modified ITT, the changes were 0.9 ± 3.2 kg (p = 0.054) and 0.9 ± 3.6 kg (p = 0.071), respectively. The were no differences between groups in secondary outcomes.CONCLUSION: Continuing or discontinuing abacavir for 48 weeks was associated with modest gains in weight that did not differ between groups. Similarly, fat distribution, or metabolic parameters were comparable between groups.