A double blind, randomised, placebo-controlled trial to evaluate the efficacy of metformin to treat preterm pre-eclampsia (PI2 Trial): study protocol

INTRODUCTION:Pre-eclampsia is a major complication of pregnancy, globally responsible for 60 000 maternal deaths per year, and far more fetal losses. There is no definitive treatment other than delivery. A therapeutic that could quench the disease process would be useful to treat preterm pre-eclampsia, as it could allow these pregnancies to safely continue to a gestation where fetal outcomes are significantly improved. We have published preclinical data to show that metformin, a drug known to be safe in pregnancy and commonly used to treat gestational diabetes, has potent biological effects making it another promising candidate to treat pre-eclampsia. Here, we describe a phase II clinical trial to examine whether administering extended-release metformin may be effective in treating women with preterm pre-eclampsia (PI2 Trial). METHODS:The PI2 Trial is a phase II, double blind, randomised controlled trial that aims to recruit 150 women with preterm pre-eclampsia (gestational age 26+0 to 31+6 weeks) who are being managed expectantly. Participants will be randomised to receive either 3 g of metformin or placebo daily. The primary outcome is time from randomisation until delivery. A delay in delivery of 5 days is assumed to be clinically relevant. The secondary outcomes will be a maternal composite and neonatal composite outcome. All other outcomes will be exploratory. We will record adverse events. ETHICS AND DISSEMINATION:This study has ethical approval (Protocol number M16/09/037 Federal Wide Assurance Number 00001372, Institutional Review Board Number IRB0005239), is registered with the Pan African Clinical Trial Registry (PACTR201608001752102) and the South African Medicine Control Council (20170322). Data will be presented at international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER:PACTR201608001752102; Pre-results.Catherine Cluver, Susan P Walker, Ben W Mol, David Hall, Richard Hiscock, Fiona C Brownfoot, Tu’uhevaha J Kaitu’u-Lino, Stephen Ton

MMP-14 is expressed in preeclamptic placentas and mediates release of soluble endoglin

Soluble endoglin is an anti-angiogenic protein that is released from the placenta and contributes to both maternal endothelial dysfunction and the clinical features of severe preeclampsia. The mechanism through which soluble endoglin is released from the placenta is currently unknown; however, recent work in colorectal cancer identified matrix metalloproteinase 14 (MMP-14) as the cleavage protease of endoglin. To determine whether this is also the mechanism responsible for soluble endoglin release in preeclampsia, we investigated the expression of MMP-14 within the placenta and the effects of its inhibition on soluble endoglin release. Placentas were obtained from severe, early onset preeclamptic pregnancies (n = 8) and gestationally matched preterm controls (n = 8). MMP-14 was predominately localized to the syncytiotrophoblast. Results from a proximity ligation assay showed protein interactions between endogenous MMP-14 and endoglin within the preeclamptic placenta. To demonstrate that this interaction produces soluble endoglin, we treated trophoblastic BeWo cells with either a broad-spectrum MMP inhibitor (GM6001) or MMP-14 siRNA. Both treatments produced a decrease in soluble endoglin (P ≤ 0.05). Treatment of mice bearing BeWo xenografts with GM6001 decreased circulating soluble endoglin levels in mouse serum (P ≤ 0.05). These findings indicate that MMP-14 is the likely cleavage protease of endoglin in the setting of preeclampsia. This approach provides a novel method for the development of potential therapeutics to reduce circulating soluble endoglin and ameliorate the clinical features of severe preeclampsia.Tu'uhevaha J.Kaitu'u-Lino, Kirsten R.Palmer, Clare L.Whitehead, Elizabeth Williams, Martha Lappas, Stephen Ton

EGFL7 gene expression is regulated by hypoxia in trophoblast and altered in the plasma of patients with early preeclampsia

INTRODUCTION:Preeclampsia is a severe complication of pregnancy, and likely arises from abnormal placental development in early pregnancy. Persistent placental hypoxia is thought to trigger the release of anti-angiogenic factors into the maternal circulation leading to widespread endothelial dysfunction. Epidermal growth factor-like domain 7 (EGFL7) is a secreted angiogenic factor that may play a key role in the disrupted angiogenesis seen in response to placental hypoxia that characterizes preeclampsia. METHODS:Primary trophoblasts were isolated and cultured in both normoxic and hypoxic conditions. Under hypoxia HIF1α was silenced and EGFL7 mRNA expression was assessed. EGFL7 mRNA expression was measured in placentas obtained from women with early (2-fold, p < 0.0001), however this was not regulated via a HIF1α dependent manner. EGFL7 mRNA expression was not altered in placenta from women with early or late onset preeclampsia. Circulating EGFL7 protein levels were not different in women with severe preeclampsia. In contrast, EGFL7 mRNA expression was increased in maternal blood in women with early onset preeclampsia (∼1.6-fold, p < 0.05). DISCUSSION:EGFL7 mRNA expression is increased with hypoxia in human trophoblast and is increased in the maternal circulation in women with preeclampsia. Further studies aimed at understanding the role and regulation of EGLF7 in the pathophysiology of preeclampsia are required.Clare L.Whitehead, Tu'uhevaha J.Kaitu'u-Lino, Natalie K.Binder, Sally Beard, Natasha De Alwis, Fiona Brownfoot ... et al

Use of metformin to prolong gestation in preterm pre-eclampsia: randomised, double blind, placebo controlled trial

OBJECTIVE To evaluate whether extended release metformin could be used to prolong gestation in women being expectantly managed for preterm pre-eclampsia. DESIGN Randomised, double blind, placebo controlled trial. SETTING Referral hospital in Cape Town, South Africa. PARTICIPANTS 180 women with preterm pre-eclampsia between 26+0 to 31+6 weeks’ gestation undergoing expectant management: 90 were randomised to extended release metformin and 90 to placebo. INTERVENTION 3 g of oral extended release metformin or placebo daily, in divided doses, until delivery. MAIN OUTCOME MEASURE The primary outcome was prolongation of gestation. RESULTS Of 180 participants, one woman delivered before taking any trial drug. The median time from randomisation to delivery was 17.7 days (interquartile range 5.4-29.4 days; n=89) in the metformin arm and 10.1 (3.7-24.1; n=90) days in the placebo arm, a median difference of 7.6 days (geometric mean ratio 1.39, 95% confidence interval 0.99 to 1.95; P=0.057). Among those who continued to take the trial drug at any dose, the median prolongation of gestation in the metformin arm was 17.5 (interquartile range 5.4-28.7; n=76) days compared with 7.9 (3.0-22.2; n=74) days in the placebo arm, a median difference of 9.6 days (geometric mean ratio 1.67, 95% confidence interval 1.16 to 2.42). Among those who took the full dosage, the median prolongation of gestation in the metformin arm was 16.3 (interquartile range 4.8-28.8; n=40) days compared with 4.8 (2.5-15.4; n=61) days in the placebo arm, a median difference of 11.5 days (geometric mean ratio 1.85, 95% confidence interval 1.14 to 2.88). Composite maternal, fetal, and neonatal outcomes and circulating concentrations of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin did not differ. In the metformin arm, birth weight increased non-significantly and length of stay decreased in the neonatal nursery. No serious adverse events related to trial drugs were observed, although diarrhoea was more common in the metformin arm. CONCLUSIONS This trial suggests that extended release metformin can prolong gestation in women with preterm preeclampsia, although further trials are needed. It provides proof of concept that treatment of preterm pre-eclampsia is possible. TRIAL REGISTRATION Pan African Clinical Trial Registry PACTR201608001752102 https://pactr.samrc.ac.za/.Catherine A Cluver, Richard Hiscock, Eric H Decloedt, David R Hall, Sonja Schell, Ben W Mol, Fiona Brownfoot, Tu, uhevaha J Kaitu, u-Lino, Susan P Walker, Stephen Ton

Maternal circulating SPINT1 is reduced in small-for-gestational age pregnancies at 26 weeks: Growing up in Singapore towards health outcomes (GUSTO) cohort study

10.1016/j.placenta.2021.05.007Placenta11024 - 28PLAC