BACKGROUND:
IMPAACT PROMISE 1077BF/FF was a randomized study of antiretroviral therapy (ART) strategies for pregnant and postpartum women with high CD4+ T-cell counts. We describe postpartum outcomes for women in the study who were randomized to continue or discontinue ART after delivery.

METHODS:
omen with pre-ART CD4+ cell counts ≥350 cells/mm3 who started ART during pregnancy were randomized postpartum to continue or discontinue treatment. Women were enrolled from India, Malawi, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe. The primary outcome was a composite of progression to AIDS-defining illness or death. Log-rank tests and Cox regression models assessed treatment effects. Incidence rates were calculated per 100 person-years. A post hoc analysis evaluated WHO Stage 2/3 events. All analyses were intent-to-treat.

FINDINGS:
1611 women were enrolled (June 2011–October 2014) and 95% were breastfeeding. Median age at entry was 27 years, CD4+ count 728 cells/mm3 and the majority of women were Black African (97%). After a median follow-up of 1.6 years, progression to AIDS-defining illness or death was rare and there was no significant difference between arms (HR: 0·55; 95%CI 0·14, 2·08, p = 0.37). WHO Stage 2/3 events were reduced with continued ART (HR: 0·60; 95%CI 0·39, 0·90, p = 0.01). The arms did not differ with respect to the rate of grade 2, 3, or 4 safety events (p = 0.61).

INTERPRETATION:
Serious clinical events were rare among predominately breastfeeding women with high CD4+ cell counts over 18 months after delivery. ART had significant benefit in reducing WHO 2/3 events in this population.