Clinical outcomes of two-drug regimens vs. three-drug regimens in antiretroviral treatment-experienced people living with HIV. Clinical Infectious Diseases.
Greenberg et al. on behalf of the RESPOND (International Cohort Consortium of Infectious Diseases) Study Group aimed to compare clinical outcomes with use of 2-drug regimens (2DRs) versus 3-drug regimens (3DRs) in people living with HIV.
Antiretroviral treatment–experienced individuals in RESPOND who switched to a new 2DR or 3DR from 1 January 2012–1 October 2018 were included. The incidence of clinical events (AIDS, non-AIDS cancer, cardiovascular disease, end-stage liver and renal disease, death) was compared between regimens.
Of 9’791 individuals included, 1’088 (11.1%) started 2DRs and 8’703 (88.9%) started 3DRs. The most common 2DRs were dolutegravir plus lamivudine (22.8%) and raltegravir plus boosted darunavir (19.8%); the most common 3DR was dolutegravir plus 2 nucleoside reverse transcriptase inhibitors (46.9%). Individuals on 2DRs were older (median, 52.6 years [interquartile range, 46.7–59.0] vs 47.7 [39.7–54.3]), and a higher proportion had ≥1 comorbidity (81.6% vs 73.9%). There were 619 events during 27’159 person-years of follow-up (PYFU): 540 (incidence rate [IR] 22.5/1000 PYFU; 95% confidence interval [CI]: 20.7–24.5) on 3DRs and 79 (30.9/1000 PYFU; 95% CI: 24.8–38.5) on 2DRs. The most common events were death (7.5/1000 PYFU; 95% CI: 6.5–8.6) and non-AIDS cancer (5.8/1000 PYFU; 95% CI: 4.9–6.8). After adjustment for baseline demographic and clinical characteristics, there was a similar incidence of events on both regimen types (2DRs vs 3DRs IR ratio, 0.92; 95% CI: .72–1.19; P = .53).
In conclusion, after accounting for demographic and clinical characteristics, there was a similar incidence of severe clinical events on 2DRs and 3DRs. 2DRs appear to be a viable treatment option with regard to clinical outcomes in the first 2–3 years of exposure, although further research on resistance barriers and long-term durability of 2DRs is needed.