In the Pipeline's Derek Lowe reminds his readers that interesting Phase II results don't always translate into successful Phase III tests. He points to Antisoma's AS404 and GenVec's TNFerade as examples. Both companies announced that their Phase III trials were being halted after it became clear that neither was going to meet its endpoints. Antisoma, and its partner Novartis, had been developing AS404 as an addition to oncology treatments, Lowe says, but the trial was halted after an interim analysis showed "basically no hope of it showing benefit if things continued." And the trial for GenVec's TNFerade – a gene therapy approach to induce TNF-alpha expression in tumors that was being studied for use as a pancreatic cancer treatment – was also halted.
So is Phase II testing meaningless? Not at all, Lowe says. Phase II trials are smaller and their patient populations more carefully selected – they're designed to show some reason to proceed and often do, he adds. "If your drug candidate makes it through Phase II, that may say more about how you designed the trial than it says about the compound," Lowe writes.