Vaginal Ring as Safe as Oral PrEP in Late Pregnancy

The long-acting dapivirine vaginal ring, which reduces HIV risk in young women, had a comparable safety profile in late pregnancy to an oral daily pre-exposure prophylaxis (PrEP) regimen, according to an interim analysis of a small open-label trial in sub-Saharan Africa.

Adverse pregnancy outcomes were rare, with one stillbirth and one neonatal death in the tenofovir disoproxil fumarate/emtricitabine (TDF/FTC; Truvada) arm out of 141 participants with pregnancy data available, reported Bonus Makanani, MBBS, of the Malawi College of Medicine-Johns Hopkins University Research Project in Blantyre, and colleagues in a late-breaking poster presented at the virtual International AIDS Society Conference on HIV Science.

Safety and efficacy data exist for the dapivirine vaginal ring among non-pregnant, reproductive-age, cisgender women, and the World Health Organization recommended it in January as a contraceptive option for women at high HIV risk. However, the authors noted that similar data were lacking for pregnant women.

MTN-042 DELIVER is an ongoing phase IIIb open-label trial in which eligible women ages 18 to 40 in South Africa, Malawi, Uganda, and Zimbabwe were randomized 2:1 to either the monthly dapivirine vaginal ring or oral TDF/FTC in the third trimester, from 36 weeks' to almost 42 weeks' gestation.

Overall, 150 participants were randomized, 101 to the dapivirine vaginal ring and 49 to TDF/FTC. Pregnancy outcome data were available for 99 women in the dapivirine ring arm and all 49 women in the TDF/FTC arm. Median age of participants was 25, with 31% reporting a prior pregnancy. Median gestational age at enrollment for both groups was about 36 weeks.

All 99 women in the dapivirine ring arm reported a live birth, with 98 reporting a full-term birth. There was one preterm birth in the dapivirine ring arm and two in the TDF/FTC arm, with 48 of 49 women reporting a live birth there.

Hypertensive disorders of pregnancy were rare, with three in the dapivirine ring arm and four in the TDF/FTC arm. Of these, all three cases in the dapivirine ring arm were gestational hypertension compared with two in the TDF/FTC arm. Two patients in the TDF/FTC arm had pre-eclampsia, one with severe features and one without. No women reported eclampsia.

Two women in the dapivirine ring arm reported postpartum hemorrhage, while two women in the TDF/FTC arm reported peripartum/antepartum hemorrhage and postpartum hemorrhage, respectively.

In addition, a woman in the TDF/FTC arm reported an incident of grade III nausea tied to the product.

Rates of adverse pregnancy outcomes were "similar to rates observed in the communities where the study is being conducted," the authors noted. "These data support plans for subsequent investigation of safety among pregnant women using dapivirine vaginal ring earlier in pregnancy."

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