A multicenter, prospective cohort study of the mutation status of patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) who are being treated with first or subsequent tyrosine kinase inhibitor (TKI) therapy in the UK, Ireland, or France.

Inclusion Criteria:

• Adult patients (age ≥ 18 years) with CML (in all phases of disease) or Ph+ ALL with detectable BCR-ABL levels who are being treated with a first or subsequent TKI.

• Patients with CML must meet the warning or failure criteria as per the ELN guidelines for first second and subsequent treatment line, including:

  • BCR-ABL/ABL IS transcripts > 10% at 3 months
  • BCR-ABL/ABL IS transcripts > 1% at 6 months
  • BCR-ABL/ABL IS transcripts > 0.1% at 12 months or later

• Patients with CML must not currently be in MMR (ie, have disease with BCR-ABL1/ABL1 transcripts > 0.1% IS).

OR

• Patients with Ph+ ALL with any level of BCR-ABL/ABL IS transcripts. Patients with Ph+ ALL should have BCR-ABL1/ABL1 transcript levels > 0.1% and should not be currently enrolled in UKALL14 but may have relapsed during or after participation in UKALL14.
• Patients with an intermediate or high Sokal score (> 0.8) can be recruited into the study from 3 months after diagnosis, irrespective of BCR-ABL1/ABL1 transcript levels at 3 months.
• Patients with additional chromosomal abnormalities at diagnosis and patients with AP-CML may be recruited into the study, irrespective of BCR-ABL1/ABL1 transcript levels at 3 months and beyond provided BCR-ABL1/ABL1 transcript levels are > 0.1% IS. It is recommended that these patients have mutational analysis performed every 3 months irrespective of BCR-ABL1/ABL1 transcript levels until they reach MR3/MMR (BCR-ABL1/ABL1 < 0.1% IS).
• Any patients who have previously undergone testing for KD mutations, irrespective of KD mutational analysis test results.
• Patients who have the ability to understand the requirements of the study and provide written informed consent.

Exclusion Criteria:

Patients without detectable BCR-ABL and patients who have switched TKI due to intolerance but who have met the criteria for optimal response (CP-CML, ELN 2013 guidelines).

Approximately 50 centers in the UK, Ireland and France that treat adult patients with CML and Ph+ ALL will be selected for participation in the study. The sites selected will be a mixture of hospital and academic centers.

The target study population will include adult patients with CML who meet the ELN criteria for warning or failure or have high SOKAL score > 0.8 or presence of additional chromosomal abnormalities (ACAs), all with detectable BCR-ABL levels. Ph+ ALL patients must have detectable BCR-ABL levels. Patients will be taking their first or subsequent TKI.

Consecutive patients within each prescriber's practice who meet the enrollment criteria and provide informed consent will be invited to enroll into the study.

Repeat NGS KD mutation testing is permitted under the protocol as deemed part of the standard management of patients.

Blood samples will be identifiable by a code consisting of numbers and initials. Samples may be stored and tested for up to 5 years after the completion of the study.