Intensified Drug Regimen May Prevent Intrapartum HIV Transmission After Late CART Start

By Reuters Staff

April 06, 2020

NEW YORK (Reuters Health) - Perinatal antiretroviral intensification may prevent intrapartum transmission of HIV in women who start combination antiretroviral therapy (cART) late in pregnancy, new research suggests.

Infants born to mothers with HIV who initiate cART soon before delivery face a high risk of perinatal transmission, Dr. Marc Lallemant of the Institut de Recherche pour le Developpement (IRD) in Marseille, France, and colleagues note in the Journal of Acquired Immune Deficiency Syndromes.

The new study was done in Thailand. It included pregnant women with HIV on standard-of-care antenatal lopinavir-based cART, followed by four weeks of zidovudine for non-breastfed infants. Those who had started cART eight weeks or less before their expected delivery were offered intensified therapy including a single dose of nevirapine at labor, two weeks of infant zidovudine-lamivudine-nevirapine, and two weeks of infant zidovudine-lamivudine.

Before starting the study, the authors modeled the probability of intrapartum transmission using data from 3,738 mother/child pairs from three previous studies they had conducted in Thailand.

In the current study, 88 women received the intensified treatment, and 234 who had started cART earlier in pregnancy served as an observational group.

There were no cases of intrapartum transmission in the intensified treatment group, and two cases in the observation group.

The authors estimated the probability of intrapartum transmission at 0.5% with antiretroviral intensification and 2.2% without intensification. There was a 94.4% probability that intensification was superior to the standard of care, and an 83.5% chance that it reduced transmission risk two-fold or more.

"This study demonstrates that perinatal antiretroviral intensification . . . significantly reduces intrapartum HIV transmission for women who received too short a cART duration to suppress viral load by the time of delivery," Dr. Lallemant and colleagues write. "Antiretroviral intensification was found to be safe and well tolerated and is recommended in the most recent Thai National guidelines."

The study had no commercial funding, and the researchers report no conflicts of interest.

SOURCE: Journal of Acquired Immune Deficiency Syndromes, online March 19, 2020.