Pregnancy Exposure Registry

There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to etravirine during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263.

Risk Summary

Prospective pregnancy data from clinical trials and the APR are not sufficient to adequately assess the risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Etravirine use during pregnancy has been evaluated in a limited number of individuals as reported by the APR, and available data show 1 birth defect in 66 first trimester exposures to etravirine-containing regimens (see Data). 

The estimated background rate for major birth defects is 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP). The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. The background risk of major birth defects and miscarriage for the indicated population is unknown.

In animal reproduction studies, no adverse developmental effects were observed with orally administered etravirine at exposures equivalent to those at the maximum recommended human dose (MRHD) of 400 mg daily (see Data). 

Data

Human Data

Based on prospective reports to the APR of 116 live births following exposure to etravirine-containing regimens during pregnancy (including 66 exposed in the first trimester and 38 exposed in the second/third trimester), the number of birth defects in live births for etravirine was 1 out of 66 with first trimester exposure and 0 out of 38 with second/third trimester exposure. Prospective reports from the APR of overall major birth defects in pregnancies exposed to etravirine are compared with a U.S. background major birth defect rate. Methodological limitations of the APR include the use of MACDP as the external comparator group. Limitations of using an external comparator include differences in methodology and populations, as well as confounding due to the underlying disease; these limitations preclude an accurate comparison of outcomes.

Etravirine (200 mg twice daily) in combination with other antiretroviral agents was evaluated in a clinical trial enrolling 15 pregnant subjects during the second and third trimesters of pregnancy and postpartum. Thirteen subjects completed the trial through postpartum period (6 to 12 weeks after delivery). The pharmacokinetic data demonstrated that exposure to total etravirine was generally higher during pregnancy compared with postpartum [see Clinical Pharmacology (12.3)]. 

Among subjects who were virologically suppressed (HIV-1 RNA less than 50 copies/mL) at baseline (9/13), virologic suppression was maintained through the third trimester and postpartum period. Among subjects with HIV-1 RNA greater than 50 copies/mL and less than 400 copies/mL at baseline (3/13), viral loads remained less than 400 copies/mL. In one subject with HIV-1 RNA greater than 1,000 copies/mL at baseline (1/13), HIV-1 RNA remained greater than 1,000 copies/mL during the study period. Thirteen infants were born to 13 HIV-infected pregnant individuals in this study. HIV-1 test results were not available for 2 infants. Among the eleven infants with HIV-1 test results available, who were born to 11 HIV-infected pregnant individuals who completed the study, all had test results that were negative for HIV-1 at the time of delivery. No unexpected safety findings were observed compared with the known safety profile of etravirine in non-pregnant adults.

Animal Data

Reproductive and developmental toxicity studies were performed in rats (at 250, 500 and 1,000 mg/kg/day) and rabbits (at 125, 250 and 375 mg/kg/day) administered etravirine on gestation days 6 through 16, and 6 through 19, respectively. In both species, no treatment-related embryo-fetal effects were observed. In addition, no treatment-related effects were observed in a pre- and postnatal development study performed in rats administered oral doses up to 500 mg/kg/day on gestation days 7 through lactation day 7. The systemic drug exposures achieved at the high dose in these animal studies were equivalent to those at the MRHD.