This is the study to test combination regimen of Nilotinib and Ruxolitinib therapy for the treatment of patients with Philadelphia positive chronic myeloid leukemia (CML) or acute lymphoblastic leukemia (ALL) who is resistant to multiple tyrosine kinase inhibitor therapies with BCR-ABL kinase inhibition activity. Ruxolitinib is a tyrosine kinase inhibitor blocking alternative pathway independent of BCR-ABL mediated pathway, thus having a potential to overcome tyrosine kinase inhibitor resistance in Philadelphia positive CML or ALL patients. Phase I study will be conducted to define a recommended phase II dose (RPTD) and phase II study will examine the hypothesis that combinational approach will increase response rate of resistant CML/ALL patients, thus evaluating efficacy of the combination regimen.