BOSULIF® (bosutinib) Mechanism Of Action

Important Safety Information

Contraindications: History of hypersensitivity to BOSULIF. Reactions have included anaphylaxis.

Gastrointestinal Toxicity: Diarrhea, nausea, vomiting, and abdominal pain occur with BOSULIF. In the study of adults with newly diagnosed CP Ph+ CML, the median time to onset for diarrhea (all grades) was 4 days and the median duration per event was 3 days. In the study of adults with CML who were resistant or intolerant to prior therapy, median time to onset of diarrhea (all grades) was 2 days, median duration was 2 days, and the median number of episodes per patient was 3 (range 1-268). Among 49 pediatric patients with CP Ph+ CML that was newly diagnosed or resistant or intolerant to prior therapy, the median time to onset of diarrhea (all grades) was 2 days, median duration was 2 days, and the median number of episodes was 2 (range, 1–198). Monitor and manage patients using standards of care, including antidiarrheals, antiemetics, and/or fluid replacement. Withhold, dose reduce, or discontinue BOSULIF as necessary.

Myelosuppression: Thrombocytopenia, anemia, and neutropenia occur with BOSULIF. Perform complete blood counts weekly for the first month and then monthly thereafter, or as clinically indicated. Withhold, dose reduce, or discontinue BOSULIF as necessary.

Hepatic Toxicity: In adults with mild, moderate, or severe hepatic impairment, the recommended starting dose is 200 mg daily. BOSULIF may cause elevations in serum transaminases (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). Out of 1711 adults in BOSULIF clinical trials, 2 cases consistent with drug-induced liver injury have occurred without alternative causes. In the study of adults with newly diagnosed CP Ph+ CML, the incidence of ALT and AST elevations was 68% and 56%, respectively. In adults with CML who were resistant or intolerant to prior therapy, the incidence of ALT and AST elevations was 53% and 47%, respectively; 60% of these patients experienced an increase in either ALT or AST.

Among 49 pediatric patients with CP Ph+ CML that was newly diagnosed or resistant or intolerant to prior therapy, the incidence of ALT and AST elevations was 59% and 51%, respectively; 76% of patients experienced an increase in either ALT or AST.

Perform hepatic enzyme tests at least monthly for the first 3 months and as clinically indicated. In patients with transaminase elevations, monitor liver enzymes more frequently. Withhold, dose reduce, or discontinue BOSULIF as necessary.

Cardiovascular Toxicity: BOSULIF can cause cardiovascular toxicity, including cardiac failure, left ventricular dysfunction, and cardiac ischemic events. Cardiac failure events occurred more frequently in previously treated adults than in those with newly diagnosed CML and were more frequent in patients with advanced age or risk factors, including previous medical history of cardiac failure. Cardiac ischemic events occurred in both previously treated adults and in those with newly diagnosed CML and were more common in adults with coronary artery disease risk factors, including history of diabetes, body mass index greater than 30, hypertension, and vascular disorders. In a randomized study of adults with newly diagnosed CML, cardiac failure occurred in 1.9% of adults treated with BOSULIF compared to 0.8% of those treated with imatinib. Cardiac ischemic events occurred in 4.9% of adults treated with BOSULIF compared to 0.8% of those treated with imatinib. In a single-arm study of adults with CML who were resistant or intolerant to prior therapy, cardiac failure was observed in 5.3% of patients and cardiac ischemic events were observed in 4.9% of patients treated with BOSULIF.

Among 49 pediatric patients with CP Ph+ CML that was newly diagnosed or resistant or intolerant to prior therapy, 4 patients (8%) had Grade 1-2 cardiac events, including tachycardia (n=2), angina pectoris, right bundle branch block, and sinus tachycardia (n=1 each). Monitor patients for signs and symptoms consistent with cardiac failure and cardiac ischemia and treat as clinically indicated. Interrupt, dose reduce, or discontinue BOSULIF as necessary.

Fluid Retention: Fluid retention occurs with BOSULIF and may manifest as pericardial effusion, pleural effusion, pulmonary edema, and/or peripheral edema. Monitor and manage patients using standards of care. Interrupt, dose reduce, or discontinue BOSULIF as necessary.

Renal Toxicity: An on-treatment decline in estimated glomerular filtration rate has occurred in patients treated with BOSULIF. Monitor renal function at baseline and during therapy, with particular attention to patients with preexisting renal impairment or risk factors for renal dysfunction. Lower starting doses are recommended for patients with renal impairment. For patients who have declining renal function while on BOSULIF or who cannot tolerate the starting dose, follow dose adjustment recommendations for toxicity.

Embryo-Fetal Toxicity: BOSULIF can cause fetal harm. Women of childbearing potential should be advised of the potential risk to the fetus and advised to use effective contraceptive measures while on treatment and for at least 2 weeks after the final dose.

Adverse Reactions: The most common adverse reactions (≥20%), in adult and pediatric patients with CML are diarrhea, abdominal pain, vomiting, nausea, rash, fatigue, hepatic dysfunction, headache, pyrexia, decreased appetite, respiratory tract infection, and constipation. The most common laboratory abnormalities (≥20%) in adult and pediatric patients are creatinine increased, hemoglobin decreased, lymphocyte count decreased, platelets decreased, ALT increased, calcium decreased, white blood cell count decreased, AST increased, absolute neutrophil count decreased, glucose increased, phosphorus decreased, urate increased, alkaline phosphatase increased, lipase increased, creatine kinase increased, and amylase increased.

CYP3A Inhibitors and Inducers: Avoid concurrent use with strong or moderate CYP3A inhibitors or strong CYP3A inducers.

Proton Pump Inhibitors (PPIs): Consider using short-acting antacids or H2 blockers instead of PPIs to avoid a reduction in BOSULIF exposure. Separate antacid or H2 blocker dosing and BOSULIF dosing by more than 2 hours.

Lactation: Because of the potential for serious adverse reactions in a nursing child, breastfeeding is not recommended during treatment with BOSULIF and for at least 2 weeks after the last dose.

Indications

BOSULIF is indicated for the treatment of:

Adult and pediatric patients 1 year of age and older with chronic phase (CP) Philadelphia chromosome-positive chronic myelogenous leukemia (Ph+ CML), newly-diagnosed or resistant or intolerant to prior therapy
Adult patients with accelerated phase (AP), or blast phase (BP) Ph+ CML with resistance or intolerance to prior therapy

Please see full Prescribing Information.