3TC+ PI dual therapy during pregnancy for PMTCT of HIV-1-naïve or pretreated women

Purpose of the study : Perinatal transmission of HIV has fallen dramatically in countries where access to antiretrovirals is available, placing the focus of research on safety. The aim of this study is to assess whether in naive or pretreated HIV-1 women, a dual, zidovudine sparing regimen (3TC+ PI) initiated during pregnancy can control maternal viral load while preventing maternal and infant toxicities related to in utero exposure to zidovudine. Methods : We performed a retrospective, descriptive study between January 2006 and 2012. Seventeen naive and 28 pretreated women who received dual therapy (3TC+PI) during pregnancy were included in the studied group and compared to 49 women on standard triple therapy (3TC/ ZDV+ PI), who delivered in the same time interval, at the same hospital. The primary endpoint was the % of women with viral loads (VL) ≤ 50 cp/ml at delivery. Secondary endpoints included % of women with VL ≤400 cp/ml after one month of dual therapy and of women who remained under dual therapy until delivery and achieved a VL ≤50 cp/ml at delivery. We also compared safety outcomes during pregnancy and until 18 months in children. Summary of results : Groups had indistinguishable median VL at day zero (200 vs. 1680, p=0.29) and gestational ages at initiation of therapy (19.6 vs 18 weeks, p=0.18). At initiation of dual therapy (in 80% of cases: 3TC+LPV/r; ATV/r or ATV), the median VL was 21,692 cp/ml (6589 to 31,269) for naive women and 43 cp/ml (20 to 200) for pretreated women. In intent-to-treat analysis of the dual therapy group, 41/45 women (91.11%, 95% CI 78.7 to 97.5%) achieved their primary endpoint. The table presents proportions of viral success at primary and secondary endpoints in the dual (N=45) and control (N=49) groups. Groups had similar proportions of cesarean section (28.8% vs 34.7%, p=0.65) and of prematurity and changes in ART due to intolerance. There was one case of MTCT for the controls and none in the dual therapy group. Newborns with prenatal ZDV exposure had higher proportions of clinical syndromes at birth (50% vs 25%, p=0.02) and SAE in the first 18 months of life (90.3% vs 68.2%, p=0.05) and worse haematological values at birth, with lower levels of haemoglobin (15.6 vs 17.5 g/dl, p=0.05). Conclusions : The 3TC+ PI dual therapy strategy in naive or pretreated women achieved a satisfactory virologic effectiveness and resulted in less SAE in the first 18 months of life and better haematological parameters at birth for children. (Published: 11 November 2012) Citation: Abstracts of the Eleventh International Congress on Drug Therapy in HIV Infection Gliga S et al. Journal of the International AIDS Society 2012, 15 (Suppl 4):18222 http://www.jiasociety.org/index.php/jias/article/view/18222 | http://dx.doi.org/10.7448/IAS.15.6.18222