Maternal Tenofovir Use May Not Adversely Affect Bone Mineral Content in Infants

BOSTON — Results from the a substudy of mothers and infants enrolled in the IMPAACT PROMISE trial showed that tenofovir use by mothers was not associated with a loss of bone mineral content in infants.

A previous study reported 12% lower newborn mean bone mineral content after maternal tenofovir disoproxil fumarate (TDF) use.

“The good news is that [these results] give some reassurance that tenofovir was not having a major adverse impact on infant bones,” George Siberry, MD, MPH, with the US Office of Global AIDS Coordinator said at CROI 2016, the annual Conference on Retroviruses and Opportunistic Infections. “Tenofovir is part of first-line regimens for pregnant and nonpregnant women throughout the world so this is very good news.”

P1084s is a nested, comparative substudy of IMPAACT PROMISE. IMPAACT PROMISE is a 3-arm trial:  

• Arm 1: zidovudine[ZDV] (+ single-dose nevirapine+ TDF/emtricitabine[FTC] tail);
• Arm 2: ZDV/lamivudine/lopinavir-ritonavir[LPVr];
• Arm 3: TDF/FTC/LPVr

Women with HIV and their infants in the substudy were randomly assigned to a maternal tenofovir-containing regimen or a no maternal tenofovir-containing regimen during pregnancy or breastfeeding for prevention of mother-to-child transmission.

In the study, 425 infants underwent whole-body and lumbar spine dual-energy X-ray absorptiometry (DXA) bone mineral content measurements by age 28 days at 8 African sites. The primary objective was pairwise comparison between arms 2 and 3.

“We saw that was there was no difference in the bone mineral content between the infants whose mothers were assigned to take tenofovir during pregnancy and those whose mothers were assigned to take the other triple ARV (antiretroviral) regimen,” Dr Siberry said. “We did however see that the bone mineral content in those infants was lower in both triple ARV arms compared to the infants whose mothers were assigned to the AZT (zidovudine) alone.”

Pairwise comparisons showed no significant differences in lumbar spine bone mineral content between arm 2 (1.64 g) and arm 3 (1.72 g). Similarly, there was no significant difference between arm 2 (65.1 g) and arm 3 (63.3 g) for whole body bone mineral content.

Researchers noted that results for lumbar spine bone mineral content and whole body bone mineral content for both groups was significant lower than arm 1. However, Dr Siberry said the benefits of triple ARV treatment for both the patient and for prevention of mother to child transmission “outweigh the concerns we see, potentially, in lower bone mineral content.”

Reference

1. Siberry G, Tierney C, Stranix-Chibanda L, et al. 36. Impact of Maternal Tenofovir Use on HIV-Exposed Newborn Bone Mineral. Presented at: CROI 2016; February 22-25, 2016; Boston, MA.

This article originally appeared on Infectious Disease Advisor