Study Finds Medication Switch to More Expensive PrEP Had No Clinical Support for Change

A majority of patients who switched to a significantly costlier medication for HIV pre-exposure prophylaxis (PrEP) had no documented clinical reason to do so, according to a study published in Open Forum Infectious Diseases. According to the investigators, the PrEP medications co-formulated tenofovir disoproxil fumarate and emtricitabine (TDF/FTC, or Truvada; Gilead) and the newer tenofovir alafenamide with emtricitabine (TAF/FTC, or Descovy; Gilead) are safe and highly effective, with no significant differences in adverse events (AEs). However, generic TDF/FTC became available in the United States in October 2020, and now costs as low as $30 per month, compared with about $1800 per month for branded TAF/FTC.

“One of the most critical barriers to broad and equitable PrEP use in the U.S. has been cost, including both perceived and actual costs,” said Julia Marcus, PhD, associate professor in the Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute, in a press release. “Generic TDF/FTC could revolutionize PrEP access, but that opportunity will be missed if resources are invested in a far more expensive medication without proportional improvements in clinical outcomes.”

PrEP is an oral antiretroviral medication that is 99% effective in preventing HIV acquisition when taken as prescribed. TAF/FTC was approved by the FDA in 2019 for the prevention of sexual transmission of HIV, except for people at risk through receptive vaginal sex. TDF/FTC has been associated with small decreases in renal function and bone mineral density, and TAF/FTC has been associated with minor weight gain and dyslipidemia, but neither medication is associated with major AEs.

To conduct the current study, the investigators used electronic health record data from 2892 adults who were assigned male sex at birth, were prescribed TDF/FTC for PrEP in the year before FDA approval of TAF/FTC, and had at least 1 PrEP prescription in the following year. They analyzed how many PrEP users switched to TAF/FTC and whether patients had a clinical indication for switching. According to the results of the study, 11.9% of the study population switched to TAF/FTC in the first year it was available.

The findings indicated that only 7% of those who switched to TAF/FTC had clinical indications to do so, based on the documented renal, bone, and cardiovascular risk factors. When including risk factors for developing renal dysfunction, such as hypertension and diabetes, up to 27% of switching was clinically indicated.

“Efforts to end the HIV epidemic may be threatened if more expensive medicines are used when comparably effective, cheaper options are available,” said Kenneth Mayer, MD, professor at Harvard Medical School and medical research director at Fenway Health, in the press release. “Our study highlights the need to ensure that decisions about PrEP medications are both clinically sound and cost-effective.”

REFERENCE

Two PrEP medications are now available. Equally safe/effective. The biggest difference? The price tag [news release]. EurekAlert; August 5, 2021. Accessed August 5, 2021. https://www.eurekalert.org/news-releases/923960