Perinatal Antiretroviral Intensification to Prevent Intrapartum HIV Transmission When Antenatal Antiretroviral Therapy Is Initiated Less Than 8 Weeks Before Delivery

• Main Authors: Marc Lallemant, Billy Amzal, Patumrat Sripan, Saïk Urien, Tim R. Cressey, Nicole Ngo-Giang-Huong, Virat Klinbuayaem, Boonsong Rawangban, Prapan Sabsanong, Thitiporn Siriwachirachai, Tapnarong Jarupanich, Prateep Kanjanavikai, Phaiboon Wanasiri, Suporn Koetsawang, Gonzague Jourdain, Sophie Le Coeur
• Format: Journal
• Published: 2020
• Subjects: Medicine
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85086524375&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/70826
• Institution: Chiang Mai University

INTRODUCTION: Infants born to women living with HIV initiating combination antiretroviral therapy (cART) late in pregnancy are at high risk of intrapartum infection. Mother/infant perinatal antiretroviral intensification may substantially reduce this risk. METHODS: In this single-arm Bayesian trial, pregnant women with HIV receiving standard of care antiretroviral prophylaxis in Thailand (maternal antenatal lopinavir-based cART; nonbreastfed infants 4 weeks' postnatal zidovudine) were offered "antiretroviral intensification" (labor single-dose nevirapine plus infant zidovudine-lamivudine-nevirapine for 2 weeks followed by zidovudine-lamivudine for 2 weeks) if their antenatal cART was initiated ≤8 weeks before delivery. A negative birth HIV-DNA polymerase chain reaction (PCR) followed by a confirmed positive PCR defined intrapartum transmission. Before study initiation, we modeled intrapartum transmission probabilities using data from 3738 mother/infant pairs enrolled in our previous trials in Thailand using a logistic model, with perinatal maternal/infant antiretroviral regimen and predicted viral load at delivery as main covariates. Using the characteristics of the women enrolled who received intensification, prior intrapartum transmission probabilities (credibility intervals) with/without intensification were estimated. After including the transmission data observed in the current study, the corresponding Bayesian posterior transmission probability was derived. RESULTS: No intrapartum transmission of HIV was observed among the 88 mother/infant pairs receiving intensification. The estimated intrapartum transmission probability was 2·2% (95% credibility interval 0·5-6·1) without intensification versus 0·3% (0·0-1·6) with intensification. The probability of superiority of intensification over standard of care was 94·4%. Antiretroviral intensification appeared safe. CONCLUSION: Mother/infant antiretroviral intensification was effective in preventing intrapartum transmission of HIV in pregnant women receiving ≤8 weeks antepartum cART.