The Life After Stopping Tyrosine Kinase Inhibitors Study (The LAST Study)

This is a non-randomized, prospective, single-group longitudinal study. The overall objective
is to improve decision making for TKI discontinuation in eligible CML patients. Patients with
CML on treatment with imatinib, dasatinib, nilotinib, or bosutinib and are in confirmed deep
molecular response will stop their TKI. Confirmed deep molecular response is defined as
BCR-ABL < 0.01%, (> MR4 i.e. > 4 log reduction) for at least 2 years. The study will closely
monitor patients using standard RQ-PCR testing for molecular recurrence, testing them monthly
for 6 months, then every other month until 24 months, and then quarterly until 36 months.
Concurrently, the study will assess a wide range of PROs before stopping TKIs and after
discontinuation in conjunction with PCR testing, though at fewer time points, utilizing
online and/or phone questionnaires. Patients who have molecular CML recurrence based on
RQ-PCR will restart imatinib, dasatinib, nilotinib, or bosutinib and will continue to be
monitored for disease status and health status until the end of the study.

Inclusion Criteria:

1. Age 18 or older at time of study entry

2. Willing and able to give informed consent

3. Diagnosed with CML in chronic phase and have either the b3a2 (e14a2) or b2a2 (e13a2)
variants that give rise to the p210 BCR-ABL protein

4. Currently taking imatinib, dasatinib, nilotinib or bosutinib

5. Patient has been on TKI therapy for at least 3 years

6. Documented BCR-ABL <0.01% (>MR4 i.e. >4 log reduction) or undetectable BCR-ABL by PCR
for at least 2 years according to the patient's local lab

7. Documented BCR-ABL <0.01% (>MR4 i.e. >4 log reduction) or undetectable BCR-ABL at
least 3 times prior to screening according to the patient's local lab

8. Two (2) Screening PCRs have been completed and both results are < 0.01% (>MR4 i.e > 4
log reduction) by central lab

9. Has been on any number of TKIs, but has not been resistant to any TKI (changes made
for intolerance are allowed)

10. Patient has been compliant with therapy per treating physician

Exclusion Criteria:

1. Prior hematopoietic stem cell transplantation

2. Poor compliance with taking TKI

3. Unable to comply with lab appointments schedule and PRO assessments

4. Life expectancy less than 36 months

5. Patients who have been resistant to previous TKI therapy are not eligible

6. Pregnant or lactating women