1265. Effectiveness and Durability of Dolutegravir (DTG)-Based Regimens in Older People Living with HIV (PLWH) from the Veterans Aging Cohort Study (VACS)

Abstract Background HIV management among older people living with HIV (PLWH) may be complicated by the presence of multiple comorbidities and polypharmacy. This study evaluated effectiveness and durability of modern 3-drug antiretroviral regimens among older PLWH. Methods Using data from the Veterans Aging Cohort Study (VACS), PLWH ≥50 years old initiating a dolutegravir (DTG), bictegravir (BIC), elvitegravir (EVG), raltegravir (RAL), or darunavir (DRV)-based 3-drug regimen for the first time between January 1, 2014, and March 31, 2020 were followed from regimen initiation (baseline) until regimen discontinuation (d/c), death, loss to follow-up, or end of study (September 30, 2020). Suppression [viral load (VL)< 50 copies/mL], change in CD4 cell count, and regimen d/c were compared between regimens 6- and 12-months post-baseline using multivariable logistic or linear regression. Virologic failure (VF; 2 consecutive VLs ≥ 200 copies/ml, or 1VL ≥ 200 copies/ml followed by regimen d/c) was evaluated over 12 months. For all outcomes, DTG-based regimens were compared to each other regimen. Outcomes were stratified by treatment experience (ART-naïve and ART-experienced). Results 2,489 ART-naive (DTG: 912, BIC: 432, EVG: 751, RAL: 159, DRV: 235) and 13,810 ART-experienced (DTG: 5097, BIC: 1765, EVG: 3582, RAL: 1486, DRV: 1880) individuals were included. Included PLWH were 97% male and 30% were ≥65 years old (Table 1). For both naive and experienced PLWH, those on DTG were more likely suppressed and had greater increases in CD4 counts at 6 and 12 months compared to those on DRV or RAL (Table 2). Odds of VF did not differ by regimen for ART-naive. For ART-experienced, DTG showed reduced likelihood of VF compared to DRV and RAL. Discontinuations within the first year were higher for RAL and DRV compared to DTG. For ART-experienced PLWH, 6-month d/c was greater for DTG vs. EVG. Regardless of treatment status, no other statistical differences in outcomes were observed between DTG-, BIC-, and EVG-based regimens. Conclusion For both ART-naïve and ART-experienced PLWH >50 years old, treatment responses during the first 12 months of follow-up were similar for those taking DTG-, BIC-, and EVG-based regimens. DTG-based regimens demonstrated greater effectiveness and durability compared to DRV- or RAL-based regimens. Disclosures Cassidy Henegar, PhD, MSPH, GlaxoSmithKline: Stocks/Bonds|ViiV Healthcare: full-time employee Charles Hicks, MD, MD, ViiV Healthcare: I am a full time employee of ViiV Healthcare. Vani Vannappagari, MBBS, MPH, PhD, ViiV Healthcare: I am full time employee of ViiV Healthcare and receive GlaxoSmithKline stock as part of my compensation package|ViiV Healthcare: Stocks/Bonds.