1049 - Weight Gain in Persons Living with HIV (PLWH) Treated with Bictegravir Compared to Other Integrase Strand Transfer Inhibitors

Background: Recent studies have given rise to the concern that some integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy may lead to weight gain in PLWH. The objectives of this study were to compare the incidence of weight gain following initiation of bictegravir (BIC) compared to other INSTIs, and to assess whether any differences were associated with changes in metabolic indices.

Methods: Patients from the VA San Diego Healthcare System (VASDHS) were included in this retrospective cohort study if they were at least 18 years old and being treated for HIV with an INSTI that was started exclusively with FTC/TAF for at least 6 months. INSTI-containing regimens were excluded if initiated with non-FTC/TAF antiretroviral agents or if the patient was pregnant, using prescription weight loss drugs, or did not have weights recorded after the start of the studied regimen. The primary outcome was weight gain at 12 and 18 months after the start of the studied regimen. Secondary outcomes included changes in parameters used to define metabolic syndrome. Statistical analysis was performed using Mann-Whitney U, Chi-square, and Spearman’s Rho tests.

Results: 560 patients with 809 instances of new INSTI prescriptions from VASDHS during November 2015 to October 2019 were reviewed for inclusion. Raltegravir-based regimens were excluded from analysis due to the limited number of eligible regimens. Study groups included group 1 (BIC, n=265), group 2 (elvitegravir/cobicistat, n=123), and group 3 (dolutegravir, n=35). There were no significant differences in baseline weight between groups. Median weight change at 12 months was 2.8 lbs. in group 1, 4.4 lbs. in group 2 (p=0.328 vs. group 1), and 5.3 lbs. in group 3 (p=0.133 vs. group 1). At 18 months, median weight change was 4.5 lbs. in group 1, 3.4 lbs. in group 2 (p=0.597 vs. group 1), and 7.7 lbs. in group 3 (p=0.585 vs. group 1). Within group 1, there was a significant increase in weight at 3, 6, 12, and 18 months compared to index date.

Conclusion: These results support the growing body of evidence associating INSTI use with weight gain, which was persistent over 18 months in all groups and in the context of a consistent FTC/TAF backbone in this study. No significant differences in magnitude of weight gain were observed between INSTIs.