This is a global, multi-center, open-label randomized and registrational phase 3 study of olverembatinib comprised of two parts: Part A and Part B. Part A is a randomized controlled part that is designed to compare the efficacy and safety of olverembatinib (investigational arm) versus bosutinib (control arm) in patients with CML-CP, previously treated with at least two tyrosine kinase inhibitors (TKIs). Part B is a single arm cohort to evaluate the efficacy and safety of olverembatinib in the CML-CP patients with T315I mutation previously treated with at least 1 TKI and without other available effective treatment options. 

Number of Subjects: A total of 285 patients will be randomized in a 2:1 ratio to either olverembatinib (n=190) or bosutinib (n=95) arm in Part A. In addition, 48 patients with T315I mutation will be enrolled in Part B.

Part A

Olverembatinib is administered orally, 30 mg, once every other day (QOD) with food. Consider dose escalation to 40 mg QOD in patients who are currently taking 30 mg QOD, do not have olverembatinib-related Grade 3 or higher adverse events and who:

• have not achieved complete hematological response (CHR) by week 8, or

• have not achieved MMR by week 12.

Part B

Olverembatinib is administered orally, 40 mg, QOD with food.

Total duration of study: 5-8 years, approximately 2 years for recruiting.

Duration of treatment:

There is no fixed duration of treatment projected for each patient. Patients are treated in the study up to the end of study treatment period, which is defined as up to 96 weeks after the last patient receives the first dose, unless patients have discontinued treatment earlier. Patients may be discontinued from treatment with study drug at any time due to unacceptable toxicity, disease progression and/or at the discretion of the investigator or the patient.