This phase II trial studies how well bosutinib works in treating patients with chronic myeloid leukemia in chronic phase after frontline tyrosine kinase inhibitor (TKI) failure. Bosutinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth.
PRIMARY OBJECTIVES: I. To assess the response rate within 24 weeks in patients in chronic phase receiving bosutinib with the starting dose of 300 mg per day, with potential escalation to 400 mg, 500 mg and 600 mg per day. SECONDARY OBJECTIVES: I. Safety of dosing schedule. II. Frequency of treatment interruptions and dose reductions. III. Determine the rate of BCR-ABL/ABL \< 10% at 3 months and \< 1% at 6 months on the international scale and the rate of complete cytogenetic response (CCyR) at 6 months after the start of treatment. IV. Determine the cumulative rate of CCyR. V. Determine the rate of major molecular response, molecular response (MR)4, MR4.5 and complete molecular response. VI. Determine long-term outcomes, including progression-free survival, event-free survival, and overall survival. VIII. Investigate the correlation between ABL kinase domain mutations, if present at the time of enrollment, with outcome. IX. Determine the rate of development and type of ABL kinase domain mutations during therapy with bosutinib. OUTLINE: Patients receive bosutinib orally (PO) daily on days 1-28. Cycles repeat every 28 days for up to 2 years in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 12 weeks for up to 2 years, every 24 weeks for 2 years.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
8
Given PO
Correlative studies
M D Anderson Cancer Center
Houston, Texas, United States
Response Rate
Response is defined as follows: 1) For patients who do not currently have a partial cytogenetic response (PCyR), achievement of major cytogenetic response is considered a response. 2) For patients who are currently in PCyR, achievement of CCyR is considered a response. The Simon's optimal two-stage design will be used for interim futility monitoring. Will be estimated along with the 95% credible interval.
Time frame: Up to 6 months
Number of Participants With Treatment Interruptions and Dose Reductions
Will be summarized.
Time frame: Up to 2 years
Rates of Major Molecular Response (MR), MR4, MR4.5 and Complete Molecular Response
Will be estimated along with the exact 95% confidence intervals. Molecular assessments are based on quantitative reverse transcriptase polymerase chain reaction for Bcr-Abl in peripheral blood. Molecular response is categorized as MMR (Bcr-Abl/Abl ratio of \</= 0.1% in the international scale), MR4 (Bcr-Abl/Abl \</= 0.01%), and MR4.5 (BCR-ABL/ABL \</=0.0032%).
Time frame: Up to 2 years
Rates of BCR-ABL/ABL <10%
Will be assessed using the international scale. Will be estimated along with the exact 95% confidence intervals.
Time frame: At 3 months
Rates of BCR-ABL/ABL < 1%
Will be assessed using the international scale. Will be estimated along with the exact 95% confidence intervals.
Time frame: At 6 months
Overall Survival
Will be assessed by Kaplan-Meier methods. Cox proportional hazards regression models will be fit to assess the association between patient characteristics including survival outcome. Time from date of treatment start until date of death due to any cause or last Follow-up.
Time frame: Up to 2 years
Event-free Survival
Time from date of treatment start until the date of first objective documentation of disease-relapse.
Time frame: Up to 2 years
Transformation-free Survival
Will be assessed by Kaplan-Meier methods. Transformation-free survival is defined as the time from treatment initiation until either progression to AP/BP or death from any cause.
Time frame: Up to 2 years
Change of ABL Kinase Domain Mutation Status
Will be summarized and its association with survival outcomes will be analyzed through landmark analyses. Cox proportional hazards regression models will be fit to assess the association between patient characteristics including ABL kinase domain mutation status.
Time frame: Baseline up to 2 years
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