A trial designed to show a new treatment is "not much worse" than an existing standard — sometimes a legitimate scientific goal, sometimes a way to get approval without proving superiority.The margin for "not much worse" (the non-inferiority margin) is set in advance and needs clinical justification. Pexiganan’s Phase III failure for diabetic foot infections was a regulatory decision about whether the non-inferiority design met the evidentiary standard — the FDA advisory committee actually voted to approve it, but the FDA rejected the NDA because it felt the non-inferiority design wasn’t the right test. This is a regulatory standard dispute, not a safety failure or evidence of inefficacy.O↑ Top