OBE022

To date, preterm labor is a condition for which only treatments with limited efficacy or restrictive safety issues are available. This includes the off-label use of tocolytics, which have a limited efficacy in suppressing uterine contractions and delaying birth.

OBE022 is a potential first-in-class, novel, orally-active prostaglandin F2α (PGF2α) receptor antagonist designed to control preterm labour by reducing inflammation and uterine contractions without causing the potentially serious vasoconstriction in the foetus (e.g. premature closure of the ductus arteriosus and/or renal impairment) seen with non-specific PG inhibitors such as indomethacin.

The PROLONG study is the first clinical trial of OBE022 in pregnant women with threatened spontaneous PTL. We reported the results of Part A of the trial, in which OBE022 was administered open-label to 9 patients with gestational ages (GA) 28 to 34 weeks, in order to assess PK and safety.

Part B of the trial, is a randomized, placebo-controlled, double-blind design to assess the efficacy, safety and PK of OBE022 in 120 patients at GA 24 to 34 weeks.

In Part A, OBE022 was well tolerated after oral administration for 7 days to women with threatened spontaneous PTL receiving atosiban. OBE022 was well absorbed; plasma concentrations and PK were comparable to those observed in non-pregnant women. OBE022 dosing regimen is 500 mg twice a day for 7 days with a loading dose of 1000 mg on Day 1.

Eight of nine patients completed the seven-day dosing period without delivering a baby.

Part B is the multicenter, randomized, double-blind, placebo-controlled portion of the trial that may enroll up to 120 patients with preterm labor at a gestational age of between 24 and 34 weeks. 

In 4Q 2019 an initial interim efficacy analysis is expected in the first 60 patients in Part B of the Phase 2a PROLONG clinical trial of OBE022 in acute preterm labor