United Skies Unfriendly After Treprostinil Flunks Oral Exam

United Therapeutics Inc. will stay in hunker-down mode for the next few months, as the company works to puzzle out exactly what the FDA wants, in the wake of a complete response letter that found the data package unacceptable in the new drug application for oral treprostinil in pulmonary arterial hypertension (PAH).