Cost-effectiveness of DTG + ABC/3TC Versus EFV/TDF/FTC for First-line Treatment of HIV-1 in the United States

Objective: Data from the SINGLE trial demonstrated that 88% of treatment-naïve HIV-1 patients treated with dolutegravir and abacavir/lamivudine (DTG + ABC/3TC) achieved viral suppression at 48 weeks compared with 81% of patients treated with efavirenz/tenofovir disoproxil fumarate/emtricitabine (EFV/TDF/FTC). It is unclear how this difference in short-term efficacy impacts long-term cost-effectiveness of these regimens. This study sought to evaluate long-term cost-effectiveness of DTG + ABC/3TC vs EFV/TDF/FTC from a US payer perspective.

Methods: This study is an individual discrete-event simulation which tracked the disease status and treatment pathway of HIV-1 patients. The model simulated treatment over a lifetime horizon by tracking change in patients' CD4 count, clinical events occurrence (opportunistic infections, cancer, and cardiovascular events), treatment switch, and death. The model included up to four lines of treatment. Baseline patient characteristics, efficacy, and safety of DTG + ABC/3TC and EFV/TDF/FTC were informed by data from the SINGLE trial. The efficacy of subsequent treatment lines, clinical event risks, mortality, cost, and utility inputs were based on literature and expert opinion. Outcomes were lifetime discounted medical costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER).

Results: Compared with EFV/TDF/FTC, DTG + ABC/3TC increased lifetime costs by $19,153 and per person survival by 0.12 QALYs, resulting in an ICER of $158,890/QALY. ICERs comparing DTG + ABC/3TC to EFV/TDF/FTC remained above the traditional, US willingness-to-pay threshold of $50,000/QALY gained in all scenarios, and above $100,000 or $150,000/QALY gained in most scenarios.

Limitations: Due to data limitations, the treatment patterns, CD4 count during viral rebound and treatment switch, viral rebound after trial end, and long-term adverse event-related treatment discontinuation were based on assumptions, presented to and approved by clinical experts.

Conclusions: Compared with EFV/TDF/FTC, DTG + ABC/3TC resulted in higher cost and only slightly increased QALYs over a lifetime, with an ICER that exceeded the standard cost-effectiveness threshold. This indicates that the incremental benefit in effectiveness associated with DTG + ABC/3TC may not be worth the incremental increase in costs.