Effective treatment with pre-exposure prophylaxis (PrEP) for HIV puts a cap on the additional cost patients should be willing to pay for long-acting injectable cabotegravir (CAB-LA), reports a US study.
The investigators conducted a simulation cost-effectiveness analysis using trial and published data, including estimated HIV incidence (5.32, 1.33, and 0.26 per 100 person-years for off-PrEP, generic oral emtricitabine–tenofovir disoproxil fumarate [F/TDF] and branded emtricitabine–tenofovir alafenamide [F/TAF], and CAB-LA, respectively). Annual base-case drug costs were $360 for generic F/TDF and $16,800 for branded F/TAF.
A total of 476,700 men who have sex with men and transgender women (MSM/TGW) at very high risk for HIV (VHR) in the US were included in the analysis. Participants on CAB-LA were compared with those on generic F/TDF or branded F/TAF for HIV PrEP.
Base-case analysis revealed that life expectancy increased by 28,000 quality-adjusted life-years (QALYs) with CAB-LA compared with generic F/TDF or branded F/TAF among those at VHR. Compared with no PrEP, branded F/TAF cost more per QALY gained than generic F/TDF.
At 10 years, CAB-LA could achieve an incremental cost-effectiveness ratio (ICER) of $100,000 per QALY relative to generic F/TDF at a maximum price premium of $3,700 per year over generic F/TDF (CAB-LA price <$4,100 per year).
In sensitivity analysis, CAB-LA could achieve an ICER of $100,000 per QALY compared with generic F/TDF at a maximum price premium of $1,100 per year over generic F/TDF (CAB-LA price <$1,500 per year) among PrEP-eligible individuals at high risk for HIV rather than at VHR (n=1,906,800; off-PrEP incidence, 1.54 per 100 person-years).
The study was limited by uncertain clinical and economic benefits of preventing future transmissions, the investigators noted.