Key Takeaways
Despite the availability of a generic version, most HIV preexposure prophylaxis (PrEP) prescriptions for commercially insured patients from 2019 to 2021 were for branded formulations, particularly Descovy (TAF/FTC).
Providers substantially overprescribe Descovy relative to its clinical value, with Descovy accounting for nearly half of 2021 commercial PrEP utilization and 60% of spending, despite offering only a modest clinical improvement over generic TDF/FTC.
If commercial insurers in the sample had replaced spending on Descovy and Truvada with generic TDF/FTC in 2021, they could have reduced their PrEP costs by $98 million, or 33% of their total spending on PrEP.
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, a technique often called ‘product-hopping2. 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 premium3. 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 $644.
Existing estimates of PrEP utilization are generally across market sectors5. 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 product6; we compare utilization by 340B status.
Methods
We used Healthcare Cost Institute (HCCI) claims data for employer-sponsored insurance to assess PrEP utilization from 2019 to 2021 by formulation. HCCI data includes approximately 55 million commercially insured individuals across all 50 states, about one-third of all individuals with employer-sponsored insurance7. We identified all patients with a claim for Descovy, Truvada, or generic TDF/FTC in each year and omitted any patients who had any claims for a separate antiretroviral during the calendar year to exclude those under HIV treatment. We identified 340B claims by linking the prescriber practice location to the 340B covered entity database using an established method8. To estimate 2021 excess spending on Truvada and Descovy, we first established the cost-effective price for Descovy by amortizing the $370 annual cost-effectiveness premium identified in the literature for TAF/FTC relative to TDF/FTC to the observed mean unit cost of generic TDF/FTC3. We note that the authors of this cost-effectiveness estimate for TAF/FTC over TDF/FTC describe it as ‘an extreme upper bound’ for the incremental value of TAF; therefore, we consider our estimates to be conservative. We then subtracted the cost-effective price for Descovy from the observed mean unit cost of Descovy and also subtracted the observed mean unit cost of generic TDF/FTC from the observed unit cost of Truvada; we then multiplied the excess per-unit costs by total units of Descovy and Truvada to estimate excess spending.
