The “Factorial on Top of Optimized Background Therapy” concept
Assuming that we can get two or more sponsors to support a salvage trial, we would like to see that trial produce the maximum useful information, while also doing it’s best to assure patient safety.
In the case of two experimental drugs, such a study might look like this:
OBT vs OBT+Drug A vs. OBT+Drug B vs OBT+A+B
Such a design allows us to examine the individual contribution of each drug, as well as the combination.