Dasatinib is a targeted therapy medication, known by the brand name Sprycel, used for specific cancers with certain genetic markers. It belongs to a class of drugs called kinase inhibitors. These drugs work by interfering with signaling pathways that allow cancer cells to grow, providing a more focused attack than traditional chemotherapy.
Medical Uses for Dasatinib
Dasatinib is approved for treating specific types of leukemia. Its primary use is for Philadelphia chromosome-positive Chronic Myeloid Leukemia (Ph+ CML), a slowly progressing cancer where the bone marrow produces an excessive number of white blood cells due to a specific genetic abnormality.
The medication is also prescribed for Philadelphia chromosome-positive Acute Lymphoblastic Leukemia (Ph+ ALL), a rapidly progressing cancer affecting immature white blood cells. Dasatinib is an option for newly diagnosed adults and for those who have become resistant or intolerant to other treatments, such as imatinib. It can also be used with chemotherapy for children over one year old with Ph+ ALL.
How Dasatinib Works
Dasatinib functions as a Tyrosine Kinase Inhibitor (TKI), blocking specific enzymes called tyrosine kinases. In patients with Ph+ CML and Ph+ ALL, the Philadelphia chromosome leads to the production of an abnormal protein known as BCR-ABL. This protein is a tyrosine kinase that is perpetually active, acting like a constant “on” switch for cell division.
This unregulated signaling causes the bone marrow to produce cancerous white blood cells uncontrollably. Dasatinib works by binding to the BCR-ABL protein, blocking its growth signals and effectively turning the “switch” off. This action halts the multiplication of cancer cells, helping to control the leukemia. Dasatinib is effective against both imatinib-sensitive and imatinib-resistant leukemia cell lines.
Administration and Dosage
Dasatinib is an oral tablet taken once each day, at approximately the same time, and can be consumed with or without food. The prescribed dosage may vary; for chronic phase CML, a common starting dose is 100 mg daily, while for advanced CML or Ph+ ALL, the initial dose is 140 mg daily. A healthcare provider may adjust the dose based on the patient’s response and any side effects.
The tablets must be swallowed whole and should not be crushed, cut, or chewed, as this can alter the drug’s absorption. If a dose is missed, skip that dose and take the next one at its regularly scheduled time. Taking two doses at once to make up for a missed one should be avoided.
Potential Side Effects
Treatment with dasatinib can lead to common side effects, which are often manageable but should be communicated to a healthcare provider. These include:
- Fluid retention (edema)
- Diarrhea
- Headaches
- Fatigue
- Skin rash
- Nausea
- Muscle and joint pain
- Mouth sores
More serious side effects can occur and require immediate medical attention. One concern is severe fluid retention, which can manifest as swelling in the limbs or as fluid accumulation around the lungs or heart. Other serious risks include bleeding events, low blood cell counts (myelosuppression), heart problems like heart failure, and pulmonary arterial hypertension (PAH).
Important Precautions and Interactions
Before and during treatment, regular monitoring is necessary, including blood tests to check blood cell counts and assess liver and kidney function. Patients should also be evaluated for any underlying heart or lung conditions before starting the therapy. The medication can cause embryo-fetal toxicity, and its use during pregnancy may harm the fetus.
Dasatinib can interact with other substances. Medications that reduce stomach acid, such as antacids and proton pump inhibitors, can decrease the drug’s absorption. It is recommended to take antacids two hours before or after the dasatinib dose. Grapefruit and grapefruit juice can dangerously increase the drug’s levels in the blood and should be avoided. St. John’s wort, an herbal supplement, can decrease dasatinib levels and should also be avoided.