How it is administered

Bosutinib is taken by mouth, usually once daily with food. It is available as tablets (100 mg, 400 mg, 500 mg) and capsules (50 mg, 100 mg). Tablets should be swallowed whole and not crushed, broken, or chewed. For patients who cannot swallow capsules, the contents can be mixed with applesauce or yogurt and taken immediately. The dose depends on age, body size (for children), and specific disease characteristics.

Typical adult doses:

• Newly diagnosed chronic phase Ph+ CML: 400 mg once daily with food
• Chronic, accelerated, or blast phase Ph+ CML with resistance or intolerance to prior therapy: 500 mg once daily with food

Pediatric doses are based on body surface area and range from 150 mg to 500 mg once daily with food.

How it works

Bosutinib is a type of medicine called a tyrosine kinase inhibitor (TKI). It works by blocking the activity of certain proteins (kinases) in cancer cells, especially the BCR-ABL protein, which is produced by the abnormal Philadelphia chromosome found in most cases of chronic myelogenous leukemia (CML).

By blocking BCR-ABL and related proteins, bosutinib helps stop the growth and multiplication of leukemia cells. This can slow down or stop the progression of CML and help bring blood counts back to normal. Bosutinib also inhibits other kinases (like Src-family kinases), which may help it work even in cases where other TKIs are less effective.

Bosutinib is effective in both newly diagnosed patients and those whose disease has not responded to or who cannot tolerate other TKIs.

Who Should take it

Bosutinib is used to treat adults and children (1 year and older) with Philadelphia chromosome-positive chronic myelogenous leukemia (Ph+ CML). It is approved for:

• Newly diagnosed chronic phase Ph+ CML
• Chronic, accelerated, or blast phase Ph+ CML that is resistant or intolerant to prior therapy (such as other TKIs like imatinib, dasatinib, or nilotinib)

It can be used as a first treatment or if other treatments have not worked or caused side effects. Your doctor will decide if bosutinib is right for you based on your specific type and stage of CML, previous treatments, and your overall health.

Who should not take it

You should not take bosutinib if you have had a severe allergic reaction (hypersensitivity) to bosutinib in the past. Symptoms of a serious allergic reaction include rash, itching, swelling, severe dizziness, or trouble breathing (anaphylaxis).

Bosutinib should be used with caution or may not be suitable for people with severe liver or kidney problems, or those who are pregnant or breastfeeding, as it can harm an unborn baby. It is also not recommended for children under 1 year old or for pediatric patients with advanced phase CML (accelerated or blast phase), as safety and effectiveness have not been established in these groups.

Always tell your doctor about all your medical conditions before starting bosutinib.

Commonly used with

Bosutinib is generally used alone as a targeted therapy for CML. It is not usually combined with other chemotherapy drugs for this disease. However, your doctor may prescribe other medications to help manage side effects, such as anti-diarrheal medicines, anti-nausea medicines, or medications to support blood counts if needed.

Commonly tested with

Bosutinib has been compared and tested with other TKIs such as imatinib, dasatinib, and nilotinib in clinical trials for CML. It is often studied in patients who have not responded to or cannot tolerate these other TKIs.

Routine blood tests are commonly performed alongside bosutinib treatment to monitor blood counts, liver and kidney function, and to check for side effects. Molecular tests to measure BCR-ABL levels are also used to monitor how well the treatment is working.