Surprise US FDA approval for United Thera's Orenitram ER for PAH

In what was seen by some observers as unexpected, the US Food and Drug Administration has approved United Therapeutic’s (Nasdaq: UTHR) Orenitram (treprostinil) extended-release tablets for the treatment of pulmonary arterial hypertension (PAH) in WHO Group I patients to improve exercise capacity. The firm's shaes rose 23% to $107.60 on the news.

Orenitram is an oral version of United’s injectable drug Remodulin, which treats the same disease. It is also marketed as Tyvaso inhalation solution. According to Mark Schoenebaum at ISI Group quoted by Forbes magazine, the approval is “an enormous surprise - arguably, one of the top 10 biggest upside surprises in the history of the biotech sector.”

For one thing, Orenitram’s benefit is not that compelling, he commented. The FDA-approved labeling for the product characterizes the treatment effect as “small.” And the FDA had already rejected it twice, in March and October 2012. It seemed nearly impossible that the medicine would be approved without additional data. Yet that’s exactly what has happened, noted Forbes.