Dabrafenib (Tafinlar®) is a kinase inhibitor and used in the treatment of certain melanomas with BRAF V600E or V600K mutation, and locally advanced or metastatic anaplastic thyroid cancer with BRAF V600E mutation with no locoregional treatment options.
Dabrafenib is also used in the treatment of metastatic non-small cell lung cancer (NSCLC) with the BRAF V600E mutation.1
How does dabrafenib work?
The BRAF V600E mutation is a specific change in the BRAF gene that has been found in some types of cancer, including NSCLC, melanoma, and colorectal cancer. The BRAF gene normally makes a protein that is involved in cell growth, and the mutation may increase the growth and spread of cancer cells.2
Dabrafenib is an inhibitor of the BRAF protein. When used in combination with trametinib, the two medications block different proteins along the same pathway that leads to the growth of cancer cells. By blocking these proteins, the combination of dabrafenib and Mekinist inhibit the growth of the cancer.1
What are the possible side effects of dabrafenib?
Dabrafenib may cause serious side effects, including tears of stomach/intestine. Patients are advised to watch for the following symptoms: bleeding, diarrhea, stomach pain, fever, and nausea. Dabrafenib may increase the risk of developing new cancers. When used alone or with trametinib, dabrafenib may cause skin cancers such as cutaneous squamous cell carcinoma, new melanoma lesions, or basal cell carcinoma. Patients should also be monitored for cancers that may not be visible on a patient’s skin.1,3
Dabrafenib can cause serious bleeding issues, including brain or stomach bleeds, and this can lead to death. Seek immediate medical attention if you have any signs of bleeding, including:
- Feeling weak
- Coughing up blood or blood clots
- Vomiting blood (may look like coffee grinds)
- Red or black stools (may look like tar)3
Tafinlar can cause heart problems, including heart failure. Your doctor should check your heart function before and during treatment with dabrafenib. Call your doctor if you have any signs of a heart problem, including:
- Racing heartbeat
- Shortness of breath
- Swelling in the feet or ankles
Dabrafenib can cause serious eye problems, and some can lead to blindness. Call your doctor if you have any signs of eye problems, including:
- Blurry vision, loss of vision, or other changes
- Seeing colored dots
- Seeing a halo around objects
- Eye pain, swelling, or redness3
Dabrafenib frequently causes a fever. Occasionally, a fever can be serious, if it causes dehydration, low blood pressure, dizziness, or kidney problems. Tell your doctor right away if you experience a fever with Tafinlar.3
Dabrafenib can cause serious skin reactions, like a rash. Call your doctor if you have any signs of skin reactions, including:
- A rash or redness that bothers you or doesn’t go away
- Redness, swelling, peeling, or tenderness of the hands or feet3
Dabrafenib can cause increased blood sugar (hyperglycemia). If you have diabetes, you will need to check your blood sugar levels closely, as dabrafenib may worsen your diabetes. Call your doctor if you have any signs of severe high blood sugar, including:
- Increased thirst
- Urinating more frequently or urinating an increased amount of urine3
Dabrafenib can cause hemolytic anemia in people with G6PD deficiency. Call your doctor if you have any signs of anemia, including:
- Jaundice (yellow skin or eyes)
- Shortness of breath3
The most common side effects experienced by NSCLC patients in clinical trials taking dabrafenib in combination with trametinib include:
- Swelling of the face, arms, and legs
- Dry skin
- Decreased appetite
- Shortness of breath3
Dabrafenib can cause fertility problems in women, which may affect your ability to become pregnant.3 This is not a complete list of side effects.
Tafinlar can cause low sperm counts in men, which can affect your ability to father a child.3
Things to know about dabrafenib
Tafinlar should only be used in in NSCLC patients who have the BRAF V600E mutation. Your doctor will perform a test to see if your NSCLC has this mutation.3
Because of the increased risk of developing some kinds of skin cancer, you should have your skin checked by a doctor before starting treatment with dabrafenib, every two months during treatment, and for up to six months after you stop taking Tafinlar for any new skin cancers. In addition, you should check your skin regularly and contact your doctor if you see any skin changes, such as a new wart, a sore or reddish bump that bleeds or doesn’t heal, or a change in the size or color of a mole.1,3
Before starting treatment with dabrafenib, talk to your doctor about all your health conditions, including:
- Bleeding problems
- Heart (cardiovascular) problems
- Eye problems
- Liver or kidney problems
- Plans to have surgery, dental, or other medical procedures
- Deficiency of the glucose-6-phosphate dehydrogenase (G6PD) enzyme
- Pregnancy or planning to become pregnant1,3
Talk to your doctor about all medications you are taking, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Dabrafenib may change how other medicines work, and certain combinations of medicine can cause side effects.3
Dabrafenib can harm an unborn baby (during pregnancy) and should not be taken by women who are pregnant or are planning to become pregnant. Women who are able to become pregnant should use effective birth control during treatment with dabrafenib and for at least four months after the last dose of dabrafenib and trametinib. Hormonal birth control methods, like birth control pills, injections, or patches, may not work as well during treatment with dabrafenib, so another form of birth control should be used (patients should discuss appropriate birth control methods with their doctor).1,3
It isn’t known if dabrafenib can pass into breast milk. Talk to your doctor if you are breastfeeding or plan to breastfeed. It is recommended that you do not breastfeed during treatment with dabrafenib and for at least four months after the last dose of dabrafenib and Mekinist.1,3
Dabrafenib should only be used in adults, as it is not known if dabrafenib is safe or effective for use in children.3
Dabrafenib comes in a capsule that is taken by mouth twice daily (in combination with trametinib for NSCLC). The medication should be taken at least one hour before or two hours after a meal. The two doses of medication should be taken approximately 12 hours apart. Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their dabrafenib (or trametinib) regimen.1
For more information, read the full prescribing information for Taflinlar.
- Taflinlar prescribing information. Available at https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/202806s002lbl.pdf. Accessed 10/3/17.
- BRAF V600E mutation, National Cancer Institute. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=721263. Accessed 10/3/17.
- Taflinlar + Mekinist medication brochure. Available at https://www.hcp.novartis.com/globalassets/products/tafmek/pdf/tafinlar-mekinist-patient-medication-guide.pdf. Accessed 10/3/17.