There are mixed data on the relationship between breastfeeding (BF) and disease progression in HIV-infected women. PROMISE 1077HS showed low rates of serious clinical events in formula-feeding (FF) women regardless of whether they continued or discontinued ART postpartum. We present clinical outcomes of predominately BF women in PROMISE 1077BF/FF and examine disease progression rates in light of those previously reported in FF women in 1077HS.
In PROMISE 1077BF/FF, HIV-infected women with pre-ART CD4 cell counts 350 cells/mm3 who started ART during pregnancy were randomized to continue (cART) or discontinue (dART) treatment after delivery. Women were enrolled from India, Malawi, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe. LPV/RTV with TDF/FTC or ZDV/3TC were the preferred study regimens. The primary efficacy endpoint was a composite of progression to AIDS-defining illness (WHO Stage 4 clinical event) or death. Log-rank tests and Cox regression models estimated treatment effects. Incidence rates were calculated per 100 person-years (PYs). A post-hoc analysis evaluated WHO Stage 2 and 3 events. All analyses were intent to treat.
1612 women from 15 sites were enrolled (June 2011-October 2014) and 95% were breastfeeding. Median age at entry was 26 years, CD4 count 698 cells/mm3 and the majority of women were Black African (97%) and enrolled from South Africa (32%), Malawi (28%), and Zimbabwe (19%). After a median follow-up of 1.6 years, there was no statistically significant difference in disease progression between arms (HR: 0.55; 95%CI 0.14, 2.08, p=0.37). WHO Stage 2 and 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 that women experienced a grade 2, 3 or 4 safety event (p=0.61). Rates of the primary endpoint, the safety endpoint, and WHO 2 and 3 events were similar to those previously reported in both arms of the FF women in 1077HS (Table).
In the largest multi-site, perinatal, randomized trial to date evaluating postpartum ART, serious clinical events were rare among women with high CD4 cell counts over 18 months after delivery, regardless of whether they received postpartum ART. Outcomes appear similar between a cohort of predominately BF women compared to FF women, suggesting no adverse impact of prolonged BF on health outcomes in women with high CD4 counts.