Elvitegravir is an integrase inhibitor used as one of the concomitant antiretroviral therapies to treat HIV-1. Cobicistat (Tybost) is a pharmacokinetic enhancer used to increase elvitegravir levels. Medicines in which elvitegravir/cobicistat are provided together are Genvoya ▼ (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) and Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil).
In July 2018, warnings issued against use of 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% and 89% lower in second and third trimester, respectively. While after 24 hours of cobicistat was 60% and 76% lower in second and third trimester, respectively.
A review of safety data and published literature has not till date identified any cases of mother-to-child HIV-1 transmission in women taking regimens containing elvitegravir/cobicistat during the second and third trimesters. However, due to 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.
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.
Healthcare professionals are advised to report suspected adverse drug reactions with black triangle drugs such as Genvoya▼and any cases of material-to-child transmission of HIV due to lack of efficacy of medicines used in HIV via the Yellow Card Scheme.