Pillar 3 - AML, page-115

I mist admit I don't fully understand why we are even doing dose escalation for FTO.
It's always mentioned that one of the pluses for Zantrene, is we know what doses are safe and work. My understanding is the dose escalation for toxicity is more relevant to chemo administration where you want to give as much as tolerable .. but for FTO we are supposed to be looking at much lower doses administered on a more frequent basis. so what is the need/advantage of doing dose escalation on a phase 2/3 drug which we keep saying Zantrene is? Is it just because of the drug combination?