Elvitegravir boosted with cobicistat: avoid use in pregnancy due to risk of treatment failure and maternal-to-child transmission of HIV-1

Pharmacokinetic data indicate exposure of elvitegravir boosted with cobicistat (Genvoya▼, Stribild) is lower during the second and third trimesters of pregnancy than postpartum. Low elvitegravir exposure may be associated with an increased risk of treatment failure and an increased risk of HIV-1 transmission to the unborn child, and therefore elvitegravir/cobicistat should not be used during pregnancy.

Advice for healthcare professionals:

  • pharmacokinetic data show low exposure values of elvitegravir boosted with cobicistat (elvitegravir/cobicistat) during the second and third trimesters of pregnancy

  • although no cases have been reported of such transmission on elvitegravir/ cobicistat therapy to date, low elvitegravir exposure may be associated with an increased risk of treatment failure and an increased risk of mother-to-child transmission of HIV infection

  • therapy with elvitegravir/cobicistat should not be initiated during pregnancy

  • switch women who are pregnant and taking elvitegravir/cobicistat to an alternative regimen

  • report suspected adverse drug reactions with HIV medicines to the Yellow Card Scheme, including treatment failure that results in harm

Background

Elvitegravir is an integrase inhibitor that is used as one of the concomitant antiretroviral therapies to treat HIV-1. Cobicistat is a pharmacokinetic enhancer used to increase elvitegravir levels. Cobicistat is available on its own as a medicine called Tybost. Medicines in which elvitegravir/cobicistat are provided together are Genvoya ▼ (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) and Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil).

Data for lower exposure in pregnancy

In July 2018, we issued warnings not to use darunavir boosted with cobicistat in pregnancy after pharmacokinetic data suggested an increased risk of treatment failure and mother-to-child transmission of HIV infection due to lower exposures during pregnancy. The risk in treatments containing elvitegravir/cobicistat has also been reviewed.

Pharmacokinetic data from IMPAACT P1026s (International Maternal Pediatric Adolescent AIDS Clinical Trials P1026 study) show that compared with paired postpartum data, plasma concentration after 24 hours of elvitegravir boosted with cobicistat was 81% lower in the second trimester and 89% lower in the third trimester. Plasma concentration after 24 hours of cobicistat was 60% and 76% lower in the second and third trimester, respectively.

A review of safety data and the published literature has not to date identified any cases of mother to child HIV-1 transmission in women taking regimens containing elvitegravir/cobicistat during the second and third trimesters of pregnancy. However, due to the theoretical risk, therapy with elvitegravir/cobicistat should not be initiated during pregnancy and women who are pregnant and taking elvitegravir/cobicistat should be switched to an alternative regimen.

Updates to product information

The product information for Genvoya▼ (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) and Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil) are being updated to recommend against use in pregnancy and a letter has been sent to relevant healthcare professionals to inform them of this information.

Report suspected adverse drug reactions with HIV medicines

Report any suspected adverse drug reactions with black triangle drugs such as Genvoya▼ on a Yellow Card. Any cases of material-to-child transmission of HIV due to lack of efficacy of medicines used in HIV should be reported on a Yellow Card.

Article citation: Drug Safety Update volume 11, issue 9; April 2019: 5.

Published 16 April 2019