United Therapeutics withdraws European application for Tyvaso

United Therapeutics will conduct an additional clinical trial for European approval of Tyvaso (treprostinil) for pulmonary arterial hypertension, which will start in early 2011 and take two to three years to complete. The firm announced it was withdrawing the marketing authorization application for the indication Feb. 19, following a major objection from the Committee for Medicinal Products for Human Use on data integrity issues; CHMP found non-compliance with good clinical practice at two clinical sites, one in the U.S. and one in the EU. The sites account for approximately 10 percent of patients in the TRIUMPH-1 study, and company management reports that without those patients, the efficacy data improves. FDA discovered similar findings at one of the sites in its own inspections, but deemed it non-critical. Tyvaso was approved in the U.S. in mid-2009. The additional trial for European approval will be designed to also expand U.S. labeling (e.g., it could include clinical worsening as an endpoint or include Class II patients, Lazard analyst Terence Flynn suggests), and will use a new, more convenient inhalation device