Treatment of spontaneous preterm labour with retosiban: a phase 2 proof‐of‐concept study. (1st June 2015)

• Record Type: Journal Article
• Authors: Thornton, Steven; Miller, Hugh; Valenzuela, Guillermo; Snidow, Jerry; Stier, Brendt; Fossler, Michael J.; Montague, Timothy H.; Powell, Marcy; Beach, Kathleen J.
• Is Part Of: British journal of clinical pharmacology. Volume 80:Number 4(2015:Oct.)
• Page Start: 740
• Page End: 749
• Publication Date: 2015-06-01
• Subjects: Pharmacology -- Periodicals; Drugs -- Periodicals; 615.1
• DOI: 10.1111/bcp.12646
• Languages: English
• ISSNs: 0306-5251

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="bcp12646-sec-0001" sec-type="section"> <title>Aim</title> <p>The aim was to investigate the efficacy and safety of intravenous retosiban in women with spontaneous preterm labour.</p> </sec> <sec id="bcp12646-sec-0002" sec-type="section"> <title>Methods</title> <p>This was a randomized, double‐blind, placebo‐controlled, phase 2 trial. Retosiban was administered intravenously for 48 h to women in spontaneous preterm labour between 30<sup>0/7</sup> and 35<sup>6/7</sup> weeks' gestation with an uncomplicated singleton pregnancy in an in‐patient obstetric unit. Outcome measures were uterine quiescence (primary endpoint), days to delivery, preterm delivery and safety.</p> </sec> <sec id="bcp12646-sec-0003" sec-type="section"> <title>Results</title> <p>Uterine quiescence was achieved in 62% of women who received retosiban (<italic>n</italic> = 30) compared with 41% who received placebo (<italic>n</italic> = 34). The relative risk (RR) was 1.53 (95% credible interval [CrI] 0.98, 2.48; NS). Retosiban resulted in a significant increase in time to delivery compared with placebo (mean difference 8.2 days, 95% CrI 2.7, 13.74). This difference was consistent across all gestational ages. The proportion of preterm births in the retosiban and placebo groups was 18.7% (95% CrI 7.4%, 33.7%) and 47.2% (95% CrI 31.4%, 63.4%), respectively. The RR of preterm birth in women treated with retosiban was 0.38 (95% CrI 0.15, 0.81). There were no deliveries within 7 days in the retosiban group, but there were six (17.6%) births in the placebo group. The maternal, fetal and neonatal adverse events were comparable in the retosiban and placebo groups.</p> </sec> <sec id="bcp12646-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Intravenous administration of retosiban in women with spontaneous preterm labour was associated with a greater than 1 week increase in time to delivery compared with placebo, a significant reduction in preterm deliveries, a non‐significant increase in uterine quiescence and a favourable safety profile.</p> </sec> </abstract>