You can’t show that it has zero effect without indefinite numbers of patients enrolled in the study. It hasn’t shown any dramatic improvements in the studies th

You can’t show that it has zero effect without indefinite numbers of patients enrolled in the study. It hasn’t shown any dramatic improvements in the studies that are there. The rest is a tradeoff between enrolling even more patients into studies to prove small improvements (or not) or to move on and spend resources on finding things that do have a major impact.