Tafinlar (dabrafenib)

Tafinlar® (dabrafenib) is used to treat certain kinds of advanced melanoma. Tafinlar can be used alone or in combination with a drug called Mekinist® (trametinib).1 Tafinlar alone is used for melanoma with a mutation called BRAF V600E. The combination of Tafinlar and Mekinist is used to treat melanoma with BRAF V600E or V600K mutation. Your doctor will test for BRAF mutation. Tafinlar is not used for melanoma with a normal BRAF gene.

Tafinlar is used when the melanoma:1

  • Cannot be removed with surgery (unresectable) or
  • Has spread to distant parts of the body (metastasized)

Tafinlar does not come in generic form. Tafinlar is similar to Zelboraf® (vemurafenib), another drug that is approved to treat unresectable or metastatic melanoma.

How does Tafinlar work?

Tafinlar is a type of medication called a kinase inhibitor.1 It works by blocking certain proteins that pass along signals for cell growth. One of the proteins is called BRAF.

Mutations in the gene (instructions) for BRAF are found in 10% of melanomas that develop on sun-exposed skin.2 BRAF mutations are found in 50% of melanomas that occur in skin that rarely has sun exposure.2 V600E and V600K are mutation subtypes. V600E is more common. This subtype makes up 80% to 90% of the BRAF mutations in melanoma.3 About 8% of BRAF mutations are the V600K subtype.4

BRAF proteins have a role in a pathway called MAPK (also called ERK). These proteins are part of a chain of events that allow cells to grow and survive. Normally, there are mechanisms that turn each protein “on” and “off,” keeping the cell processes under control. Certain mutations cause BRAF to stay “on,” sending continuous signals for uncontrolled cell growth.5

Tafinlar turns the BRAF protein off. It is called a targeted therapy because it targets one feature that makes cancer cells different from normal cells.

Mekinist is a drug that inhibits a protein called MEK. Tafinlar and Mekinist can be used together to target the MAPK pathway at two points. This combination stops or slows the growth of melanomas with BRAF mutations better than either drug alone.1

How effective is Tafinlar?

Tafinlar was studied in alone and together with Mekinist. All of the patients in these trials had metastatic or unresectable melanoma with BRAF V600 mutations.

Treatment-Naïve Patients. Among patients who had not had other melanoma treatment, 52% had a response to Tafinlar.1 “Response” has to do with whether the tumor shrinks or grows more slowly while on treatment. Response is only about tumor changes and it does not measure whether you—as a whole patient—have improved. Response is also different from survival. Response to treatment can be partial or complete. In this trial, 3% had a complete response and 48% had a partial response. The response lasted for a median of 5.6 months.

Progression-free survival is how long a person survives after treatment without the cancer getting worse. The median progression-free survival in this study was 5.1 months.1

Patients with Brain Metastasis. Tafinlar was studied in patients with brain metastases. Half the study participants’ brain metastases had been treated before with surgery or radiation therapy and half were untreated. Regardless of treatment history, 18% of participants had a response to treatment.1 Median duration of response was 4.6 months in both groups.1

Tafinlar plus Mekinist. Two trials were done to study patients with unresectable or metastatic melanoma who had not been treated for melanoma before. One study compared Tafinlar plus Mekinist with Tafinlar alone. The other study compared Tafinlar plus Mekinist with Zelboraf alone.

Combination therapy resulted in:

  • Greater response to treatment
  • Fewer deaths
  • Longer overall survival
  • Fewer people with cancer progression
  • Longer time until cancer progression

Median progression-free survival for patients receiving combination treatment was about 9 to 11 months. Median overall survival was 25 months in one trial; in the other trial, the median has not been reached. About 65% of people had a response to treatment.1

How do I take Tafinlar?

Before taking Tafinlar, read the Medication Guide that comes in the package. Follow your doctor’s instructions for taking Tafinlar.

Tafinlar comes as a capsule that you take by mouth.1 Do not open, crush, or break the capsules. Take Tafinlar twice a day, approximately 12 hours apart. Take Tafinlar at least 1 hour before or 2 hours after a meal.

You will continue taking Tafinlar until the cancer progresses or the side effects are unacceptable.1

What are the side effects of Tafinlar?

Taking Tafinlar alone or with Mekinist can cause other cancers.1 It has been linked to another type of skin cancer called squamous cell carcinoma or new melanoma lesions. Tafinlar with Mekinist is linked with new basal cell carcinoma. Possible signs of new cancers include: new wart, skin sore, reddish bump, or mole that changes in size or color.

The most common side effects of Tafinlar alone or with Mekinist are:

  • Thickening of the skin
  • Headache
  • Joint aches
  • Cough
  • Warts
  • Hair loss
  • Skin reaction on the hands or feet
  • Rash

Less common but serious side effects are:

  • Bleeding problems in the brain or stomach
  • Heart problems
  • Eye problems
  • Fever
  • Severe skin reaction
  • Increased blood sugar
  • Low red blood cells (anemia)

Tafinlar may make it difficult to get pregnant or father a child. If this is a concern for you, discuss this with your doctor.

Who should not take Tafinlar?

Pregnant women should not take Tafinlar.1 Women who could become pregnant should use birth control during treatment. Continue using birth control for at least 2 weeks after the last dose of Tafinlar or 4 months after taking Tafinlar with Mekinist. Hormonal birth control (pills, injections, patches) may not work during treatment. Discuss effective birth control options with your doctor.

Do not breastfeed while taking Tafinlar. Do not breastfeed for 2 weeks after the last dose of Tafinlar or 4 months after Tafinlar with Mekinist.

Tell your doctor about any other medical conditions you have, especially:1

  • Bleeding problems
  • Heart problems
  • Eye problems
  • Liver problems
  • Kidney problems
  • Diabetes
  • An enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD)

Tell your doctor if you have had or are planning to have surgery, dental work, or other medical procedures.

What precautions are needed when taking Tafinlar?

Regular skin exams are needed while taking Tafinlar.1 Your doctor will do a skin exam before you start this medication. You will need skin exams every 2 months while taking Tafinlar and for up to 6 months afterward. Your doctor will also look for non-skin cancers.

During treatment and for at least 2 weeks after the last dose of Tafinlar or 4 months after Tafinlar and Mekinist:1

  • Women who can become pregnant should use non-hormonal birth control, such as condoms.
  • Women should not breastfeed.
Written by: Sarah O'Brien | Last reviewed: May 2017.
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