Imatinib (GLEEVEC)

Philadelphia chromosome positive (Ph+) Chronic myeloid leukemia  

Philadelphia chromosome positive (Ph+) Acute Lymphoblastic Leukemia (ALL)

Gastrointestinal Stromal Tumor (GIST)

Philadelphia chromosome positive (Ph+) Chronic myeloid leukemia

• Oral: Chronic phase - 400mg once daily continuously until disease progression or unacceptable toxicity  
• Oral: Accelerated or blast phase – 600-800mg once daily continuously until disease progression or unacceptable toxicity  

Philadelphia chromosome positive (Ph+) Acute Lymphoblastic Leukemia (ALL)

• Dose – Oral: 400-800mg once daily
• Dosing may differ depending on practice site with regards to how long to take imatinib and when to stop prior to transplant. Please refer to local protocol
• Given in combination with chemotherapy

Gastrointestinal Stromal Tumor (GIST)

• Dose – Oral: 400mg once daily continuously
• For disease progression, dose may be increased to 400mg twice daily continuously

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Note: Dividing 800mg once daily dosing into 400mg twice daily dosing is suggested to reduce iron exposure

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Available as 100 mg, 400 mg tablets. Tablets can be dissolved for patients unable to swallow them, please discuss with your pharmacy team. Store at room temperature.

BCR-ABL Tyrosine Kinase Inhibitor

Take with food to avoid gastric irritation

Once daily dosing: If a dose is missed, patients should be instructed to take it as soon as they can if it is within 12 hours of the missed dose. If it is over 12 hours since the missed dose, patients should skip the missed dose and resume with the next scheduled dose.

Twice daily dosing: If a dose is missed, patients should be instructed to take it as soon as they can if it is within 6 hours of the missed dose. If it is over 6 hours since the missed dose, patients should skip the missed dose and resume with the next scheduled dose.

Common: Anemia, Neutropenia, Thrombocytopenia, Edema, Diarrhea, Nausea.

Less Common: Elevated bilirubin, Elevated ALT/AST/alkaline phosphatase.

The adverse effects listed above are not exhaustive. Please refer to the relevant product monograph for full details.

Monitoring for GIST tumors

Baseline: HBsAg,HBcoreAb

Every 4 weeks for cycles 1, 2 and 3, then at least every 3 months: CBC and diff, platelets, creatinine, bilirubin, alkaline phosphatase, ALT, LDH

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Monitoring for Leukemia

Baseline before treatment: CBC & differential, platelets, ALT, bilirubin, serum creatinine, BUN, body weight, bone marrow examination for cytogenetic analysis, FISH, RT-PCR (for BCR/ABL transcripts), BCR-ABL mutational analysis, ECG, HBsAg, HbcoreAb.

For disease progression: 

• CBC & differential, platelets: weekly until complete hematological response, then monthly.
  • After 6 months and if patient is clinically stable, may increase interval to every 3 months at the physician’s discretion.
• Serum creatinine, uric acid, ALT, bilirubin: weekly until stable then monthly.
  • After 6 months and if patient is clinically stable, may increase interval to every 3 months at the physician’s discretion.
• BCR-ABL transcripts every 3 months until MMR achieved and maintained for at least 12 months.
  • Frequency of transcript testing can then move to every 6 months.

Monitoring for dose modifications:

• First month: Weekly CBC & diff, Platelets, ALT, Bilirubin
• Month 2-6: Monthly CBC & diff, Platelets, ALT, Bilirubin
• After 6 months: CBC & diff, Platelets, ALT, Bilirubin every 3 months

• This drug can impact or be impacted by metabolic enzymes for absorption and excretion. Many drugs can also affect or be affected by these enzymes, so please consult with pharmacy to assess for interactions.
• Avoid grapefruit, grapefruit juice, Seville oranges, or Seville orange juice.
• Current drug interaction databases should be consulted for more information.

• Avoid in pregnancy and lactation.
• Imatinib is commonly associated with edema and occasionally serious fluid retention. Patients should be weighed and monitored regularly for signs and symptoms of fluid retention, weight gain, and edema (risk increases with higher doses and age >65 years). Edema is usually mild to moderate and most frequently periorbital or in lower limbs but may include pleural effusion, ascites, pulmonary edema and rapid weight gain with or without superficial edema.
• Reactivation of hepatitis B virus (HBV) has been reported in patients who are chronic carriers of HBV and received BCR-ABL TKIs. Patients should be tested for HBV infection prior to initiating treatment. Carriers of HBV must be monitored for signs and symptoms of active HBV infection throughout therapy and for several months following termination of therapy.

BC Cancer. BC Cancer Drug Manual. Imatinib.  Vancouver, British Columbia: BC Cancer Agency. Available at:http://www.bccancer.bc.ca/drug-database-site/Drug%20Index/Imatinib_monograph.pdf . Updated January  1, 2024. Accessed January 22, 2024.

Lexicomp. Imatinib Monograph. In: Lexi-Drugs. Hudson, Ohio: Lexi-Comp, Inc. Available at: https://online-lexi-com.qe2a-proxy.mun.ca/lco/action/doc/retrieve/docid/patch_f/7072?cesid=5JeA3i0GuOn&searchUrl=%2Flco%2Faction%2Fsearch%3Fq%3Dimatinib%26t%3Dname%26acs%3Dtrue%26acq%3Dimatinib. Updated January 27, 2024. Accessed January 31, 2024.

Cancer Care Ontario. Imatinib Monograph. Drug Formulary. Toronto, Ontario: Cancer Care Ontario. Available at: https://www.cancercareontario.ca/en/drugformulary/drugs/monograph/43866. Updated June 2019. Accessed January 22, 2024.

Novartis Pharmaceuticals Canada Inc. GLEEVEC® Product monograph. Dorval, Quebec. Updated August 31, 2022.