Safety and Efficacy of RLX030 in Pregnant Women With Pre- Eclampsia

Key Inclusion criteria: * Written informed consent was obtained before any assessment was performed. * Women at 18 to 40 years of age with a pregnancy 28 weeks (0 days) and 33 weeks (+4 days) gestational age. Gestational age was based on mother's last menstruation; if last menstruation was unknown, an alternative method was used as applicable and was documented in the (electronic) Case Report/Record Form \[(e)CRF\]. * Women with a diagnosis of pre-eclampsia or superimposed pre-eclampsia requiring hospitalization. Pre-eclampsia was defined as new onset of hypertension (SBP ≥ 140 or DBP ≥ 90 mmHg) or gestational hypertension accompanied by proteinuria (\>= 0.3 g/24h) after 20 weeks of gestation. Superimposed pre-eclampsia was defined as chronic hypertension with new onset of proteinuria after 20 weeks of gestation. * Reassuring fetal testing (cardiotocography and biophysical profile) Key Exclusion criteria: * Severe hypertension (SBP ≥ 160 mmHg or DBP ≥ 110 mmHg) and /or those receiving anti-hypertensive treatment at time of randomization. * Clinically relevant electrocardiogram (ECG) abnormalities at screening excluding those abnormalities commonly seen in pregnancy according to the Investigator. * Symptoms indicative of severe pre-eclampsia or HELLP syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelet count) for which immediate delivery of the baby may be indicated. Symptoms include persistent CNS symptoms (severe headaches, visual changes, altered mentation), persistent right upper quadrant or epigastric pain, nausea or vomiting, severe thrombocytopenia (\<100,000/mm3) and abnormal (\> 2X upper limit of normal) liver enzymes (alanine aminotransferase \[ALT\] or aspartate aminotransferase \[AST\]). * Eclampsia during current pregnancy, vaginal bleeding present at screening, abruptio placentae, oligohydramnios * Current diagnosis of a seizure disorder that requires chronic medication. * Pre-gestational diabetes (Type 1 or Type 2) with or without diabetic retinopathy. Diagnosis (previous or current) of gestational diabetes, regardless of treatment, was allowed * Known allergy to magnesium sulfate or steroids. * Multifetal gestation, known major fetal anomaly, intrauterine growth restriction (\<5th percentile).