The short answer would be yes. It's how to do it that would be the challenge.
There are some real challenges, in that these trials, which are typically called phase three trials, which are the human, reasonably large-population trials on the basis of which an application for licensing is submitted, take time. I know one worry might be that it may take enough time that what was a comparator when the study was designed may not be a comparator anymore when it's completed, and how does it affect the marketability of the product if that was the comparator used? That's one question that does get asked when that question comes up.
However, as far as I know, there are companies who do earlier trials using existing treatments instead of placebo. So I think somehow we should encourage, if nothing else, a move to that. But that requires some agreement on what a comparator will be.
Australia was one of the first countries to develop guidelines for what a submission should contain for reimbursement purposes, particularly the economic part of it. Canada followed soon after. These were the two leading countries in the early 1990s. At the time, in Australia the industry would ask that question: tell us what comparator you want. Typically, what the companies are told is to provide all the information they have, and then we will judge it.
So I think that if a comparator is to be used instead of a placebo, there should be some agreement beforehand by all parties that it would be accepted as a comparator in a reasonable amount of time. It just can't be rejected because a new, more effective technology in the meanwhile has come in and has taken over the bulk of the practice.