FDA warns that Prezcobix should not be used by HIV-positive pregnant women

Prezcobix is the brand name of a pill containing the anti-HIV drug darunavir and the boosting agent cobicistat. The purpose of cobicistat is to raise and maintain levels of darunavir so that once-daily dosing can be effective. However, during pregnancy, a woman’s weight increases and the standard dose (or combination) of some anti-HIV drugs may not be sufficient.

In June 2018, the U.S. Food and Drug Administration (FDA) changed the prescribing information on Prezcobix. It stated that Prezcobix should not be used by pregnant women because of “substantially lower exposures of darunavir and cobicistat during pregnancy.”

The FDA also stated that “an alternative regimen is recommended for women who become pregnant during therapy with Prezcobix.” It did not list a specific alternative regimen.

The recommendation by the FDA is based on data from a study of seven pregnant HIV-positive women who were evaluated during their second and third trimesters as well as 12 weeks after giving birth. Six women completed the study. The FDA reported that the concentrations of darunavir and cobicistat were very low during the second and third trimesters of pregnancy. Furthermore, one woman had virological failure (viral load greater than 1,000 copies/mL) during the third trimester of her pregnancy. The FDA did not release data on the HIV infection status of the infants born to these women.

—Sean R. Hosein


Struble K, Thompson E, Stanfield M. Prezcobix label. FDA HIV email updates. 5 June 2018.