Inclusion Criteria:

- Participant must have a histologically or cytopathologically confirmed blast phase
Ph+ CML or Ph+ ALL.

- Participant is 18 years of age on the day of signing informed consent

- Participant must have performance status 0-3 on the Eastern Cooperative Oncology
Group (ECOG) Performance Scale

- Participant has at least 30 percent blasts in peripheral blood; or at least 30
percent lymphoblasts in peripheral blood or bone marrow

- For Part II:

- Participant has progressed while taking imatinib or is unable to tolerate imatinib,
being defined as discontinuing imatinib treatment as a result of nonhematologic toxic
effects of any grade

- If female, participant is either post-menopausal, free from menses for >2 years,
surgically sterilized or willing to use 2 adequate barrier methods of contraception
to prevent pregnancy or agrees to abstain from heterosexual activity throughout the
study, starting with Visit 1

- Female participants of childbearing potential must have a negative serum or urine
pregnancy test (beta hCG) at screening

- If male, participant is surgically sterilized, agrees to use an adequate method of
contraception, or agrees to abstain from heterosexual activity for the duration of
the study

- Participant or the patrticipant's legal representative has voluntarily agreed to
participate by giving written informed consent

- Participant must be available for periodic blood sampling, study related assessments,
and management at the treating institution for the duration of the study

Exclusion Criteria:

- Participant is currently participating in or has participated in a study with an
investigational compound or device within 30 days or 5 half-lives, whichever is
longer, of the start of treatment

- Participant has known human immunodeficiency virus (HIV) infection or HIV-related
malignancy

- Participant is a female who is pregnant or breastfeeding, or is expecting to conceive
within the projected duration of the study

- Participant has a known allergy or hypersensitivity to imatinib, dasatinib or
nilotinib

- Participant has a history or current evidence of any condition, therapy, or
laboratory abnormality that might confound the results of the study, interfere with
the participant's participation for the full duration of the study, or is not in the
best interest of the participant to participate

- Participant has known psychiatric or substance abuse disorders that would interfere
with cooperation with the requirements of the trial

- There is any concern by the investigator regarding the safe participation of the
participant in the study or for any other reason, the investigator considers the
participant inappropriate for participation in the study