I would resist to apply a full dose combination chemotherapy. Recovery of normal hematopoiesis is impossible in CML and the whole treatment aims to prepare for transplant.
Therefore, Dasatinib 100 mg/d should be the start, combined with an individually dosed chemotherapy with Ara-C and a intermediate dose of an anthracyclin.
A full dosed 7+3 or similar will result in long lasting cytopenias and may be disadvantageous.
With some more information about timing (diagnosis until myeloid sarcoma, histology of the lesions (% blasts), BCR-ABL mutations, cytogenetics) I would be happy to provide more detailed advice if you would like me to.