If DNDN did that, they'd be completing a filing that shows pieces of efficacy across different stages of disease, hoping that the FDA would consider it whole.
I would look at it differently - that they are asking for approval of 9901 and P-11 would be supporting data (vs contradictory data in the event of a complete bust).
As you know I actually consider favorable data in multiple stages to actually be stronger data than, say, two trials in one stage. But on this I think we will agree to disagree.