I think combination treatments are possible, but safety and tolerability are probably going to be a significant barrier to overcome, especially for chronic phase patients. I think we are more likely to see them first being used in refractory patients rather than upfront as a potentially curative treatment.
The idea of combination treatments is to target the cancer stem cells, so this is actually something you would try in well-controlled chronic phase patients rather than refractory patients. Combinations of a potent TKI with a hedgehog inhibitor is one such idea, but others have also been suggested.