(1117) Efficacy Outcomes in Virologically Suppressed People Living with HIV-1 Receiving Dolutegravir/lamivudine Across Age Groups: TANDEM Subgroup Analysis

Objectives: Aging with HIV has unique challenges, including comorbidities and drug-drug interactions. TANDEM was a retrospective medical chart review conducted across 24 US sites. This subgroup analysis examines stable-switch people living with HIV-1 receiving dolutegravir/lamivudine by age.

Methods: Eligible individuals were adults initiating dolutegravir/lamivudine prior to Sept/30/2020 with ≥6 months of clinical follow-up. Stable-switch individuals were defined as having HIV-1 RNA < 50 copies/mL and on a stable antiretroviral regimen for ≥3 months upon dolutegravir/lamivudine initiation. Clinical characteristics, treatment history, and outcomes were analyzed for 3 age groups among dolutegravir/lamivudine stable-switch individuals. Analyses were descriptive.

Results: The number of dolutegravir/lamivudine stable-switch people living with HIV-1 in each age group was 86 ( < 50 years), 106 (≥50 years), and 20 (≥65 years). A greater proportion of individuals in the older age groups were female sex at birth (14.0% < 50 years; 20.8% ≥50 years; 30.0% ≥65 years). More people in the older age groups had reported comorbidities (12.8% < 50 years; 34.9% ≥50 years; 45.0% ≥65 years) and polypharmacy (5.8% < 50 years; 17.9% ≥50 years; 30.0% ≥65 years). Avoidance of long-term toxicities was the biggest driver for initiating dolutegravir/lamivudine in the older age groups (32.1% ≥50 years; 30.0% ≥65 years) while simplification/streamlining of treatment was the most common (27.9%) primary reason for people to switch to dolutegravir/lamivudine in the < 50 years group. For individuals aged < 50 years, 95.3% remained virologically suppressed for the study period. Similarly, 96.2% of people aged ≥50 years and 95.0% of those aged ≥65 years remained virologically suppressed for the study period. Three individuals with NRTI resistance at baseline remained suppressed.

Conclusions: Virological suppression rates were high and similar by age group among dolutegravir/lamivudine stable-switch people living with HIV-1 despite higher rates of comorbidities and polypharmacy in the older age groups. This real-world analysis is consistent with clinical study data supporting dolutegravir/lamivudine as an effective treatment strategy in individuals aged ≥50 years.