Abstract
In a cross-sectional analysis of HIV preexposure prophylaxis (PrEP) utilization by commercially insured patients from 2019 to 2021, most prescriptions were for branded formulations of PrEP despite the availability of a generic version. Accounting for the modest relative clinical benefit of branded TAF/FTC (tenofovir alafenamide fumarate/emtricitabine) PrEP over generic TDF/FTC (tenofovir disoproxil fumarate/emtricitabine) PrEP, use of generic TDF/FTC PrEP would have reduced commercial insurers’ spending by 33%.
Introduction
In October 2019, Descovy (tenofovir alafenamide fumarate/emtricitabine; TAF/FTC) received an indication for HIV prophylaxis, the second drug to do so following Truvada (tenofovir disoproxil fumarate/emtricitabine; TDF/FTC) [1]. Descovy is a prodrug of Truvada whose clinical development was delayed to coincide with the expiry of Truvada patents [1], a technique often called ‘product-hopping [2]’. Descovy offers an extremely modest clinical improvement over TDF/FTC; switching all current preexposure prophylaxis (PrEP) patients from TDF/FTC to Descovy would generate a 5-year 0.1% increase in QALYs, meriting only a $370 annual premium [3]. Generic TDF/FTC was released in August 2020; in 2021, list prices for generic TDF/FTC were less than $1 per pill while branded Truvada cost $61 and Descovy cost $64 [4].
Existing estimates of PrEP utilization are generally across market sectors [5]. This article presents the first disaggregation of PrEP utilization by formulation in the commercially insured market and estimates unnecessary spending on Truvada and Descovy instead of generic TDF/FTC. Prior commentary suggested 340B Program providers may over-prescribe Descovy instead of generic TDF/FTC because of greater revenue on the brand product [6]; we compare utilization by 340B status.