FDA's Norman Stockbridge wants to abandon thorough QT studies by 2015, replacing them with a preclinical assay suite better able to detect proarrhythmia side effects than existing assays. However, it remains unclear whether two years is sufficient time to develop and validate the assays to a level that convinces stakeholders the QT trials are no longer necessary.

According to Stockbridge, director of CDER's Division of Cardiovascular and Renal Products, the new approach is needed because the focus on QT prolongation under the agency's current guidance has likely hindered drug development, potentially killing compounds that do not in fact cause fatal arrhythmia.