AMAG seeks answers as approved preterm birth drug no better than placebo

Shares in AMAG Pharmaceuticals (Nasdaq: AMGA) slipped by nearly 18% on Friday after a drug that was approved by the US Food and Drug Administration (FDA) in 2011, failed in a confirmatory study.

The PROLONG trial is a randomized, double-blinded, placebo-controlled clinical study evaluating Makena (hydroxyprogesterone caproate) in patients with a history of a prior spontaneous singleton preterm delivery.

"The majority of patients in the PROLONG trial were enrolled outside of the USA, predominantly from Eastern European countries, with very different demographics"It was conducted as part of an approval commitment under the FDA’s Subpart H accelerated approval process.