Imatinib (Gleevec) — Glivec: The First Targeted CML Therapy
Imatinib is a living legend in oncology, often called the first "magic bullet" that changed the lives of millions. Before its discovery, Chronic Myeloid Leukemia (CML) was a fatal diagnosis. Imatinib turned this deadly cancer into a manageable chronic condition that patients can live with for decades.
Known by the brand name Gleevec (or Glivec), it acts like a molecular switch. It specifically targets and blocks the BCR-ABL tyrosine kinase protein produced by the "Philadelphia chromosome." Essentially, Imatinib turns off the signal that tells cancer cells to multiply, leaving healthy cells largely untouched.
It remains the "Gold Standard" of targeted therapy: an oral medication taken at home, allowing patients to maintain a normal quality of life.
Indications
- Chronic Myeloid Leukemia (CML): For adults and children with Philadelphia chromosome-positive (Ph+) CML in chronic, accelerated, or blast crisis phases.
- Gastrointestinal Stromal Tumors (GIST): For patients with Kit (CD117) positive unresectable and/or metastatic malignant tumors.
- Other rare conditions: Dermatofibrosarcoma protuberans (DFSP), Hypereosinophilic syndrome (HES).
Dosage and administration
Success with Imatinib relies on discipline and protecting your stomach.
- Standard Dose: Typically 400 mg or 600 mg once daily.
- The Golden Rule: Take the tablet with a meal and a large glass of water (at least 200 ml). This is crucial to prevent nausea and stomach irritation.
- Missed Dose: If you forget a dose, do not double up. Just take the next scheduled dose the following day.
- Hypersensitivity to Imatinib.
- Pregnancy and breastfeeding (teratogenic risk to the fetus).
- Severe liver failure (requires dose adjustment).
- Children under 2 years of age (for CML).
Imatinib is generally well-tolerated but has signature side effects.
- Edema (Very Common): Fluid retention, specifically puffiness around the eyes (periorbital edema) and swelling in the legs. Limiting salt intake often helps.
- Muscles: Muscle cramps, especially in the legs/calves. Magnesium or calcium supplements may help (consult your doctor).
- Digestive: Nausea, vomiting, diarrhea (mitigated by taking with food).
- Skin: Rash, itching, dryness.
