Zelboraf (vemurafenib)

Zelboraf® (vemurafenib) is used to treat advanced melanoma with a mutation called BRAF V600E. Your doctor will test for BRAF mutation. Zelboraf is not used for melanoma with a normal BRAF gene.

Zelboraf is used when the melanoma:1

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

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

Zelboraf can be used alone, or it may be used together with a drug called Cotellic® (cobimetinib).

How does Zelboraf work?

Zelboraf is a type of medication called a kinase inhibitor. 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

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.3

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

Cotellic is a drug that inhibits a protein called MEK. Zelboraf and Cotellic are sometimes used together to target the MAPK pathway at two points. Some patients have better results with combination treatment than with Zelboraf alone.4

How effective is Zelboraf?

Zelboraf was studied in different groups of patients with melanoma. All of the patients had metastatic or unresectable melanoma with BRAF V600E mutations. Some had tried other melanoma treatments, such as interleukin-2 or Yervoy® (ipilimumab).5 Others had not been treated before.6 One study was conducted in patients with melanoma that had spread to the brain (brain metastasis).7 Results from each of these studies are described below. Together, they show that the melanoma shrinks or grows more slowly in about 50% of people treated with Zelboraf.6 This response typically lasts 5 to 7 months.4

Treatment-Naïve Patients. Among patients who had not had other melanoma treatment, 48% had a response to Zelboraf.6 “Response” has to do with how the tumor changes during treatment and the effectiveness of the treatment on the tumor. Response 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.

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 5.3 months.1

In this study, 84% of participants were alive 6 months after starting Zelboraf.6 The median overall survival for treatment with Zelboraf was 13.6 months.1 Median overall survival is the length of time from treatment that half the study population is still alive. In this case, 337 people were treated with Zelboraf. A little more than 13 months later, half the study participants (about 169 people) were still alive.

Previously Treated Patients. A separate study was done of people who had previously been treated for melanoma with interleukin-2 or Yervoy. Overall, 52% of participants had a response to Zelboraf.1 This included 2.3% with a complete response and 50% with a partial response. Response to treatment lasted a median of 6.5 months.1

Patients with Brain Metastasis. In patients with brain metastases, 18% of participants had a response to treatment.1 The overall response rate was the same whether patients had been treated before or not. Nearly all patients had a partial response, rather than a complete response. A small percentage (2%) of the previously untreated patients had a complete response; none of the treatment-experienced patients did. Previous treatment for the brain tumor included surgery or radiation therapy. Median duration of response was 4.6 to 6.6 months, depending on treatment history.1

How do I take Zelboraf?

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

Zelboraf comes as a tablet that you take by mouth.1 Do not crush or chew the tablet. Take Zelboraf twice a day, 12 hours apart. You can take it with or without food.

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

What are the side effects of Zelboraf?

Taking Zelboraf can cause other cancers.1 It has been linked to another type of skin cancer called squamous cell carcinoma. It also may cause squamous cell carcinoma in locations other than the skin. Some people have developed new melanoma lesions while taking Zelboraf. 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 Zelboraf are:1

  • Joint pain
  • Rash (can be severe)
  • Hair loss
  • Tiredness
  • Sensitivity to the sun and sunburn
  • Nausea
  • Itching
  • Warts

Less common but serious side effects include allergic reactions, severe skin reactions, changes in your heart rhythm, liver or kidney damage, or eye problems.

Who should not take Zelboraf?

Pregnant women should not take Zelboraf.1 Women who could become pregnant should use birth control during treatment and for at least 2 weeks after the last dose. Do not breastfeed while taking Zelboraf or for 2 weeks after the last dose.

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

  • Heart problems
  • Liver problems
  • Kidney problems
  • Low levels of potassium, calcium, or magnesium in your blood

Tell your doctor if you have had or are planning to have radiation therapy.

What precautions are needed when taking Zelboraf?

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

Try to avoid sunlight while taking Zelboraf.1 This medication makes your skin sensitive to sunlight and you may burn more easily. If you are outside, wear a wide-brimmed hat and long clothing. Use sunscreen and lip balm with a sun protection factor (SPF) of 30 or more.

During treatment and for at least 2 weeks after the last dose of Zelboraf:1

  • Women who can become pregnant should use birth control.
  • Women should not breastfeed.
Written by: Sarah O'Brien | Last reviewed: May 2017.
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